GW100 - Building OData Services Using SAP NetWeaver Gateway

GW100 Building OData Services Using SAP NetWeaver Gateway SAP NetWeaver

Date Training Center Instructors Education Website

Participant Handbook Course Version: 97 Course Duration: 3 Day(s) Material Number: 50111052

An SAP course - use it to learn, reference it for work

Copyright Copyright © 2012 SAP AG. All rights reserved. No part of this publication may be reproduced or transmitted in any form or for any purpose without the express permission of SAP AG. The information contained herein may be changed without prior notice. Some software products marketed by SAP AG and its distributors contain proprietary software components of other software vendors.

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SAP, R/3, SAP NetWeaver, Duet, PartnerEdge, ByDesign, SAP BusinessObjects Explorer, StreamWork, SAP HANA, and other SAP products and services mentioned herein as well as their respective logos are trademarks or registered trademarks of SAP AG in Germany and other countries. Business Objects and the Business Objects logo, BusinessObjects, Crystal Reports, Crystal Decisions, Web Intelligence, Xcelsius, and other Business Objects products and services mentioned herein as well as their respective logos are trademarks or registered trademarks of Business Objects Software Ltd. Business Objects is an SAP company. Sybase and Adaptive Server, iAnywhere, Sybase 365, SQL Anywhere, and other Sybase products and services mentioned herein as well as their respective logos are trademarks or registered trademarks of Sybase Inc. Sybase is an SAP company. Crossgate, m@gic EDDY, B2B 360°, and B2B 360° Services are registered trademarks of Crossgate AG in Germany and other countries. Crossgate is an SAP company. All other product and service names mentioned are the trademarks of their respective companies. Data contained in this document serves informational purposes only. National product specifications may vary.

Disclaimer These materials are subject to change without notice. These materials are provided by SAP AG and its affiliated companies (“SAP Group”) for informational purposes only, without representation or warranty of any kind, and SAP Group shall not be liable for errors or omissions with respect to the materials. The only warranties for SAP Group products and services are those that are set forth in the express warranty statements accompanying such products and services, if any. Nothing herein should be construed as constituting an additional warranty.

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About This Handbook This handbook is intended to complement the instructor-led presentation of this course, and serve as a source of reference. It is not suitable for self-study.

Typographic Conventions American English is the standard used in this handbook. The following typographic conventions are also used. Type Style

Description

Example text

Words or characters that appear on the screen. These include field names, screen titles, pushbuttons as well as menu names, paths, and options. Also used for cross-references to other documentation both internal and external.

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Example text

Emphasized words or phrases in body text, titles of graphics, and tables

EXAMPLE TEXT

Names of elements in the system. These include report names, program names, transaction codes, table names, and individual key words of a programming language, when surrounded by body text, for example SELECT and INCLUDE.

Example text

Screen output. This includes file and directory names and their paths, messages, names of variables and parameters, and passages of the source text of a program.

Example text

Exact user entry. These are words and characters that you enter in the system exactly as they appear in the documentation.

Variable user entry. Pointed brackets indicate that you replace these words and characters with appropriate entries.

© 2012 SAP AG. All rights reserved.

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About This Handbook

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Icons in Body Text The following icons are used in this handbook. Icon

Meaning For more information, tips, or background

Note or further explanation of previous point Exception or caution Procedures

Indicates that the item is displayed in the instructor's presentation.

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Contents Course Overview .......................................................... ix Course Goals ........................................................... ix Course Objectives ..................................................... ix

Unit 1: Gateway Overview and Introduction ......................... 1 Introduction to Gateway ................................................3 Introduction to REST ................................................. 22 Introduction to OData................................................. 30

Unit 2: Gateway Data Model Generator ............................. 61 Generating Data Model for Read ................................... 62 Generating Data Model for Update ................................100

Unit 3: Gateway Service Monitoring ................................ 129 Monitoring Gateway .................................................130

Unit 4: OData Channel Model Provider ............................ 137 Developing Model Provider Class .................................138 Creating Gateway Services.........................................159 Creating Complex Types............................................185

Unit 5: OData Channel Data Provider .............................. 201 Developing Data Provider Class for Read ........................202 Developing Data Provider Class for Update......................233 Using Associations and Navigation Paths ........................263

Unit 6: Front-end Application Development ...................... 281 Consuming Gateway Services .....................................282

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Contents

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Course Overview Target Audience This course is intended for the following audiences: • •

ABAP application developers Business Process developers

Course Prerequisites Required Knowledge • •

BC400 Introduction to the ABAP Workbench BC401 ABAP Objects

Recommended Knowledge • •

BC402 Advanced ABAP Java, JavaScript, HTML

Course Goals This course will prepare you to: • •

Use SAP NetWeaver Gateway to connect to data of a NetWeaver Application Server ABAP. Consume Gateway Services on different platforms and in different programming languages.

Course Objectives After completing this course, you will be able to: • • • • •

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Understand the various development and installation options for SAP NetWeaver Gateway. Explain what functionality SAP NetWeaver Gateway do and does not provide. Understand how to generate a Gateway Service starting from an RFC ABAP Function Module or an Object from the Business Object Repository. Develop from scratch your own Gateway Service in ABAP. Consume a Gateway Service using either a Java application or a JavaScript (browser) based application.


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Course Overview

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Unit 1 Gateway Overview and Introduction Unit Overview This unit provides you with a semi-technical introduction to the Gateway software and how it functions within the wider scope of an SAP system landscape. It covers the different installation options for Gateway, and how each installation option then affects the manner in which Gateway Services are developed. This is followed by an introduction to the concepts of how Gateway services are actually developed. Once developed, a Gateway service can then be consumed by applications written in a wide variety of programming languages. Since the topic of REST and RESTful services is widely talked about in software marketing and the computing press, an entire (short) chapter is provided to explain exactly what REST is – and more importantly, what REST is not. The last lesson of Unit 1 provides a semi-technical introduction to the OData protocol and its history. It shows how XML messages are structured and how they can be interpreted.

Unit Objectives After completing this unit, you will be able to: • • • • • • • •

Understand the high-level architecture of SAP NetWeaver Gateway Understand the different deployment and development scenarios Understand the different development options for creating Gateway Services and consuming Gateway Services Understand what Representational State Transfer (REST) is. Understand how REST has been implemented as HTTP(S). Understand the architecture of the Atom and OData protocols. Understand how SAP NetWeaver Gateway makes use of OData. Understand how to issue read-only OData requests from your browser.

Unit Contents Lesson: Introduction to Gateway ................................................3 Lesson: Introduction to REST .................................................. 22

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Unit 1: Gateway Overview and Introduction

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Lesson: Introduction to OData ................................................. 30 Exercise 1: Getting Started with OData .................................. 51

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Lesson: Introduction to Gateway

Lesson: Introduction to Gateway Lesson Overview This lesson covers: • • •

The high-level architecture of SAP NetWeaver Gateway The different deployment and development scenarios The different development options for – –

Creating Gateway Services Consuming Gateway Services

Lesson Objectives After completing this lesson, you will be able to: • • •

Understand the high-level architecture of SAP NetWeaver Gateway Understand the different deployment and development scenarios Understand the different development options for creating Gateway Services and consuming Gateway Services

Business Example High Level Gateway Architecture

Figure 1: SAP NetWeaver Gateway – High Level Architecture

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Gateway sits in between an SAP Business Suite or ECC 6.0 system and the outside world. When we say the “outside world”, what is meant is any software external to the backend Business Suite or ECC system. Typically, this will be some client-based application that consumes an OData service and interacts directly with an end user. However, it is also possible for the Gateway interface to supply information to server-based software, which then forwards the information to one or more client devices. In the case of SAP Workflow events, the Gateway interface can push a workflow event out to some server that consumes the information and then forwards its it to however many client devices have subscribed to that event. The software to consume workflow events coming out of the SAP system is not covered in the GW100 training course. The Sybase Unwired Platform (SUP) software offers a possible solution to event consumption, but is not the only software option a customer could use. Open The OData interface is an open standard that can be consumed by any software or device that can communicate using the HTTP(S) protocol and can parse and construct an XML document. People Gateway has been designed to provide a Business to Consumer (B2C) interface. Although it would be technically possible to use Gateway in a B2B style interface, this would be a use case that lies outside SAP's intended set of use cases for Gateway. Timeless Since the Gateway software has been implemented as a set of ABAP add-ons, these can be deployed to a wide range of SAP Business Systems. Delivery of the Gateway software as ABAP add-ons ensures the minimum level of interference with existing systems. Developers There are two major advantages that come with the use of an OData interface: •

•

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The OData interface is implemented using either XML or JSON. Both of these formats are well known, plain text protocols for the transmission of information over the Web. Irrespective of the protocol used to transmit an OData message, that message is self-describing. Therefore, any Web developer will be able to understand the message content without needing to have any internal knowledge of how an SAP system works.


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In the past, there has always been the issue that in order to consume SAP functionality from an external program over the RFC interface, developers have needed to have at least a basic knowledge of the internal workings of an SAP system. Now however, when taken together, these two factors lower the consumption barrier to the lowest possible level. A developer now needs no knowledge of the internal workings of an SAP system in order to consume a Gateway (OData) service. Standards The Gateway interface implements the OData protocol as described on www.odata.org

Figure 2: What is the Open Data Protocol (OData)?

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OData is a Microsoft developed standard that is built on the existing Atom Publishing and Atom Syndication protocols. •

Prior to development of OData, there were some major standardisation problems with the use of RESTful APIs. This topic will be covered in more detail in chapter 3 where we look at the specific details of OData, and how OData improves on the underlying protocols such as Atom.

•

The term “ODBC for the Web” is conceptually accurate, but there is no sense in which OData allows you to execute an exact SQL statement over the Web. Nonetheless, the OData interface exposes an API that allows collections of entities to be retrieved using syntax that provides a similar level of functionality to that offered by SQL. There is no cost or license agreement needed for the use of OData. The standard is open and can be used by anyone who cares to implement it. One of the reasons SAP chose to implement OData (over Google's GData) was that OData is extensible. This is particularly useful in cases where SAP specific values need to be described in this protocol; for instance, currency fields. A currency field contains two separate values, the currency amount and the currency code. These two values must always be treated as a linked pair, and OData's extensibility allows for this.

• •

Development and Deployment Scenarios

Figure 3: SAP NetWeaver Gateway Deployment Scenarios: 1/3

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In the first deployment scenario, the Gateway add-ons are deployed to an independent server that acts as the communication end point for all OData communication. This server is known as the “Gateway Hub” and does not hold any business data. •

In this scenario, the backend server needs to have the IW_BEP component installed. The IW_BEP component allows an ABAP programmer to develop a Gateway service directly in the back end server. This service is then exposed to the outside world through the Gateway Hub server.

The advantage of this development and deployment scenario is that the Gateway Service is developed within the same server wherein the actual business data resides. This development scenario offers the ABAP developer a much greater range of business flexibility. •

This deployment scenario relies on the fact that the customer permits the installation of add-ons into their productive system. It cannot be assumed that all customers will allow this.


As far as the deployment of SAP NetWeaver Gateway add-ons is concerned, this slide is identical to the previous slide. However, if the customer has no in-house ABAP developers, then it is possible to create Gateway Services using the service generation tool. This tool runs directly in the Gateway Hub and generates a fully functional Gateway service. No ABAP coding is needed.

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The generated service is executed in the Gateway Hub server, and relies on the fact that the required functionality is available from the backend server in the form of BAPIs or RFC Function Modules. Alternatively, if a basic ABAP dynpro screen implements the required functionality, then a Gateway Service can be created using screen scraping. For this to work, the IW_SCS component must be installed in the backend system. Either way, no ABAP coding needs to be written.


There are several situations in which it will not be possible to install the add-ons IW_BEP or IW_SCS into the backend business system. Either: The backend system is the wrong version (too old) to support these add-ons, or The installation of add-ons into the customer's system landscape would necessitate a repeat of some external compliance certification (this is particular true for customers in the defence or pharmaceuticals sectors), or The complexity of the customer's system landscape makes the installation of IW_BEP (and therefore the development of Gateway services directly on the backend server) impractical. Note: IW_BEP can also be installed in the Gateway Hub.

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Custom Gateway services can be developed in whichever system contains IW_BEP; the difference here however is that since the custom Gateway Service is running in the Gateway Hub and not directly in the backend, RFC calls will need to be made into the backend system in order to perform the required business functionality. For partner organisations developing their own Gateway Service, it is safe first to assume that IW_BEP cannot be installed in the backend business system. This is known as the non-invasive approach to Gateway Service development. That is, a Gateway Service developed using IW_BEP functionality, but this is for IW-BEP installed in the Gateway Hub, not the backend business system. A Backend Operation Proxy (BOP) is a wrapper that can be generated in the Gateway Hub in order to call an RFC module in the backend system. Such a wrapper is needed in cases where the Gateway Hub server and the backend business system are running on different SAP system versions. Not only this, but very often, the ABAP dictionary fields used to describe an RFC module's interface in the backend business system may well not exist in the Gateway Hub. In these cases it is necessary to have a wrapper generated that uses simple data types to describe the fields in the RFC module's interface. BOPs can be generated by accessing the transaction through the IMG.

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•

In this case, the backend system could be any at version back to R/3 4.6C.

•

Since the backend system cannot have any add-ons installed (either because it is too old, or because the customer does not permit it), the Gateway Service will not be able to use any screen scraping or event push functionality offered by IW_SCS and IW_BEP respectively.


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This is known as the all-in-one option. •

•

•

This is where all the Gateway add-ons are installed directly on the backend business system. This scenario is suitable for proof-of-concept development, or the deployment of Gateway Services within an intranet only environment. The backend server must conform to the minimum requirements for a Gateway Hub server, since the backend system has now become the Gateway Hub server. This is scenario is most definitely not recommended for deployment of services to the public internet since this would make the backend server directly accessible from the public internet.

The advantage of having a separate Gateway Hub server is that it sits in your network DMZ and communicates with the backend server through a firewall. This ensures that only the Gateway Hub server is visible to the public Internet and not the actual business system.

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Gateway Service Development

Figure 7: SAP NetWeaver Gateway Development Tools: Generators

SAP NetWeaver Gateway content generators do not support direct coding of the Gateway Service. They allow not only the reuse of existing Business Objects or screens but also provide data adaptation capabilities. Data coming from multiple objects can be aggregated, filtered and adapted based on the client application requirements. These generators can be used to generate structures that are then enhanced using the programming tools. Generation of new GW Data Models based on recordings of SAP transaction screens, and enables information from the recorded transactions to be consumed in an OData compliant way. Dynpro based Gateway Services utilize the transaction recorder (Batch Input) in order to capture business processes from the SAP System. However, any dynpros that contain web or ActiveX controls are not supported. The Gateway Service Generator is a tool that will take a BAPI, RFC Module or basic Dynpro as input, and from it create a Gateway service. This option is suitable for prototyping or where ABAP development skills are not available.

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Figure 8: Gateway Services Based on RFMs or BOR Objects Overview

The screen shot is taken from the RFC and BAPI Gateway Service Generation Tool. It shows that the individual CRUD operations are mapped to RFC modules.

Figure 9: Gateway Services Based on Screen Scraping Overview

This screen shot is taken from the Screen Scraping Gateway Service Generation Tool. It shows much the same information as the previous slide, except that individual CRUD operations are mapped to screens instead of function modules.

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Figure 10: Screen Scraping – When to Use

Two of the most frequent use cases for screen scraping are to expose search help functionality and to implement simple button push events for ABAP Dynpros where such functionality has not equivalent over the RFC interface.

Figure 11: Gateway Service Mapping Tool

General features provided by the service mapping tool.

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Figure 12: SAP NetWeaver Gateway Development Tools: Good ol' ABAP

ALREADY IN NOTES: The development of custom Gateway services takes place in whichever system component IW_BEP has been installed. This component provides (among other things) the ABAP classes that act as super-types for your own Gateway classes. From the perspective of developing custom Gateway Services, it is important to understand that this type of development takes place in whichever system the component IW_BEP has been installed. For partners developing a Gateway Service that is to be sold to a wide range of SAP customers (i.e. you cannot predict whether the customer will permit the installation of the IW_BEP add-on in their system landscape), the development will take place in the Gateway Hub. However, it could be...

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Figure 13: SAP NetWeaver Gateway Development Tools: Good ol' ABAP

... the backend server – as long as the installation of add-ons is permitted.

Figure 14: Gateway Service Architecture (OData Channel) – 1/5

When creating a Gateway Service, two distinct ABAP classes need to be developed. The metadata provider class defines the service's interface. The information provided by this class is used when an external application wishes to consume a Gateway Service. This class provides the consumer with a full description of the entities available from this service and how those entities are associated with each other.

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The data provider class provides the actual runtime implementation of the business functionality described by the metadata class.


There is no direct programmatic relationship between the model and data provider classes. This may at first seem strange because most developers assume that if the data provider class is going to output information, then it will need to have a reference to the model provider class in order to understand its own interface. In fact, this is not the case. •

The relationship between the data and model provider classes is implemented through configuration, not coding. Two different configuration wrappers need to be created.

A configuration wrapper is created for the model provider class. •

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And a configuration wrapper is created for the data provider class.


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ALREADY IN NOTES: The configuration screen asks you to enter the internal service name and then uses this value as the external service name. Be careful to enter the name here that you want the end user to see. There is no need to start the internal service name with a Z character, and remember that the value you enter is case-sensitive. When the configuration wrapper for the data provider class (Service Group) is created, you need to supply an internal service name. • •

The internal and external service names are important because The name you specify for the internal name is copied to the external name

Also, the external name becomes the name seen by the user in the URL when addressing the Gateway Service from outside the SAP system. It is very important therefore that the external name is relevant and meaningful for the end user. This means that the name used for the internal name must also be relevant and meaningful to the end user. In other words, do not use a name starting with Z or some other technical internal name.

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Once you have created the two configuration wrappers, these are associated with each other by a further configuration step, and you have a Gateway Service. However, that service is not quite ready to use.


ALREADY IN NOTES: Creating an entry in the Service Catalog takes place in whichever SAP system has the GW_CORE component. This may well be a different system than the one in which you developed the Gateway Service.

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The final step is to create a Service Catalogue entry. This is done in whichever server acts as the Gateway Hub – which depending on which deployment scenario you are using, may, or may not, be the same system in which the Gateway Service was developed. •

After the Service Catalogue entry has been created, the Gateway Service can be accessed from some external client device or browser.

Gateway Service Consumption

Figure 19: Consuming a Gateway Service: General Approach

ALREADY IN NOTES: SAP does not make any recommendations or impose any restrictions on which development language should be used for the consumption of a Gateway service. You can use any language with which you are familiar so long as that language has facilities for HTTP(S) communication, and can construct and parse an XML document. Beyond that, you are free to use any language you like.

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Figure 20: Consuming a Gateway Service: IDE Plug-Ins

ALREADY IN NOTES: The Gateway consumption tools will create a proxy object that wraps access to a Gateway service. This object can then be used in your own application. Optionally, the consumption tools will also generate a basic application that makes use of the generated proxy object. The Gateway consumption tools are not designed to generate fully functional applications. Instead, they are designed jump start your development process by creating a basic, but functional application that can then be used as the starting point for the development of your own application. The Gateway consumption tools are available for the following languages: • • •

Java C# Objective C

SAP offers various tools for OData proxy objects in Java, C# and Objective C. These proxy objects can then be included in a client device application. •

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Nonetheless, the use of these tools is not mandatory. On the www.odata.org website, many different OData libraries can be downloaded for a wide variety of languages.


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Lesson Summary You should now be able to: • Understand the high-level architecture of SAP NetWeaver Gateway • Understand the different deployment and development scenarios • Understand the different development options for creating Gateway Services and consuming Gateway Services

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Lesson: Introduction to REST Lesson Overview This lesson covers: • •

What Representational State Transfer (REST) is and is not How the principles of REST have been implemented as HTTP(S)

Lesson Objectives After completing this lesson, you will be able to: • •

Understand what Representational State Transfer (REST) is. Understand how REST has been implemented as HTTP(S).

Business Example REST - The Foundation of the World Wide Web

Figure 21: Correcting A Common Misunderstanding

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Lesson: Introduction to REST

ALREADY IN NOTES: The term “Representational State Transfer” or REST was first introduced by Roy Fielding in his doctoral dissertation “Architectural Styles and the Design of Network-based Software Architectures ” published in 2000. •

•

•

REST is not a network protocol! Nonetheless, there is a widespread misunderstanding that REST is some kind of network protocol and you will often see boxes or arrows in system block diagrams labelled “REST”. Such diagrams are just simply wrong! REST is a set of six architectural constraints, or design principles. Anyone so motivated could build a RESTful software system. As long as the software is designed to follows these standards, your home-grown software will be genuinely RESTful. The World Wide Web is the best example of a RESTful system.

Figure 22: The Architectural Constraints of REST - 1/6

The example of client and server software being developed independently is demonstrated by the fact that browsers are developed and released independently of webservers.

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When a browser communicates with a proxy server, it does so in exactly the same way as it would if it were communicating directly with the target webserver. This is an example of the layering principle in REST.


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Stateless communication is one of the defining features in RESTful communication. This constraint however is often misunderstood to mean that the server never holds any form of state information about the client. This is not the case though: if the server chooses to hold state information about the client, that's fine. It's just that the client must always know and be always be able to identify the session state held by the server. This is typically achieved in a browser by setting a session state cookie.


A uniform interface is one that always means the same thing to the participants at all times. Firstly the server has to provide the client with some consistent representation of a resource it is holding. In OData, this achieved by the server sending an XML or JSON message to the client that conforms to a known syntax and structure. •

Once the client has received a representation of the server side resource, the client must additionally have some means for altering the state of (or manipulating) that resource.

This is where the CREATE, READ, UPDATE, DELETE operations have been defined, since these four operations are the most fundamental that can be performed by a client on a server-side resource. •

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A RESTful response sent to a client must not be structured in such a way that the client needs to make subsequent request to the server to provide further clarification or explanation of what the information in the first message meant. In other words, all REST communication must be self-describing. A hypermedia link is defined as the only acceptable mechanism by which the client can manipulate a server-side resource.


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This one principle has been isolated and given the acronym HATEOS, or “Hypermedia As The Engine Of Application State” •

HATEOS is generally regarded as the core concept of REST.


In order to improve communication efficiency, servers should define that transmitted information is cacheable. In this way, if a client requires the same information again, it can look in its local cache to find it rather than issue duplicate network requests.

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If a client detect that it does not have the correct capability to handle the information is has (or is about to) receive, it can make a request to server send is some executable coding that will extend its functional capability. This is an academic way of describing what happens when a browser requests a JavaScript file etc.

HTTP - An Implementation of the Principles of REST

Figure 28: HTTP(S) - An Implementation of the REST Constraints

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ALREADY IN NOTES: There is much more that could be said about how HTTP implements the principles of REST; however, the key point here is to understand that HTTP(S) provides you with the ability to manipulate server-side resources through the use of the methods GET, PUT, POST and DELETE. The HTTP protocol that drives the World Wide Web is an example of a fully RESTful communication system. The four fundamental operations are described using the acronym CRUD.

Figure 29: Summary

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Lesson Summary You should now be able to: • Understand what Representational State Transfer (REST) is. • Understand how REST has been implemented as HTTP(S).

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Lesson: Introduction to OData Lesson Overview This lesson covers: • •

The architecture of the Atom and OData protocols • How SAP NetWeaver Gateway makes use of OData How to issue read-only OData requests from your browser

Lesson Objectives After completing this lesson, you will be able to: • • •

Understand the architecture of the Atom and OData protocols. Understand how SAP NetWeaver Gateway makes use of OData. Understand how to issue read-only OData requests from your browser.

Business Example Atom and OData

Figure 30: What is the Open Data Protocol (OData)?

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Lesson: Introduction to OData

OData is a Microsoft developed standard that is built on the existing Atom Publishing and Atom Syndication protocols. •

Prior to development of OData, there were some major standardisation problems with the use of RESTful APIs. This topic will be covered in more detail in chapter 3 where we look at the specific details of OData, and how OData improves on the underlying protocols such as Atom.

•

The term “ODBC for the Web” is conceptually accurate, but there is no sense in which OData allows you to execute an exact SQL statement over the Web. Nonetheless, the OData interface exposes an API that allows collections of entities to be retrieved using syntax that provides a similar level of functionality to that offered by SQL. There is no cost or license agreement needed for the use of OData. The standard is open and can be used by anyone who cares to implement it. One of the reasons SAP chose to implement OData (over Google's GData) was that OData is extensible. This is particularly useful in cases where SAP specific values need to be described in this protocol; for instance, currency fields. A currency field contains two separate values, the currency amount and the currency code. These two values must always be treated as a linked pair, and OData's extensibility allows for this.

• •

For more detailed information, please refer to http://www.odata.org

Figure 31: What is Atom?

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The Atom Syndication format is the foundational protocol that does little more than provide an XML description of: • • •

Various documents that are available from a website Each document is structured as a “feed” Within a “feed, the consumer will find zero or more units of information known as ”entities

The Atom Publishing protocol that allows the XML data provided by Atom Syndication to be manipulated using HTTP. The problem with both of these Atom formats is that they do not provide a mechanism for describing the data being transported. In other words, they offer no facility for providing a metadata description of the data they provide.

Figure 32: What Does OData Add to Atom?

OData adds the ability to define the metadata of an Atom message. This in turns means that an OData message can now be consumed by an external service without that service first needing to know the message's structure. In other words, the Atom feed can now provide the consumer with a description of itself.

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Figure 33: Output Formats Supported by OData

ALREADY IN NOTES: Although it is not as convenient as JSON, languages such as JavaScript can consume XML format messages using libraries such the one found at http://datajs.codeplex.com The consumption of a Gateway XML message directly in JavaScript is also documented in the SAP How To Guide “How To: Consume A Gateway Service From JavaScript”. http://www.sdn.sap.com/irj/sdn/gateway?rid=/library/uuid/505619a7-73bf-2e10fe96-da9a86b23120 • •

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The Gateway server will be able to output an OData message in JSON format once SP4 is installed and the kernel has been patched. In SP3 and earlier, a Gateway system can only out OData messages in XML format.


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Figure 34: OData Service Documents - The Starting Point

The starting point for consuming an OData service is to issue the URL for the service's Service Document. The Service Document provides the top-level description of an OData service.

Figure 35: OData Service Documents - General Structure

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The XML received in the OData Service Document is always structured with a element as the root element, under which in a element. Within the element is a single element followed by zero or more <collection> elements. Figure 36: An Example of an OData Service Document - 1/3 Figure 37: An Example of an OData Service Document - 2/3 2012 © 2012 SAP AG. All rights reserved. 35 Unit 1: Gateway Overview and Introduction GW100 Figure 38: An Example of an OData Service Document - 3/3 Figure 39: Accessing an OData Collection - Construct the URL The URL used to derive an OData service's Service Document is known as the “Base URL”. When working with an OData message in XML format (as opposed to JSON format), the base URL is always listed as the xml:base parameter of the <service> element. Within the Service Document, the URLs that point to collections provided by that service are listed as URLs relative to the base URL. 36 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData Figure 40: Accessing an OData Collection - A Structured Response Figure 41: Understanding OData XML - 1/4 The XML seen here has been shortened for clarity 2012 © 2012 SAP AG. All rights reserved. 37 Unit 1: Gateway Overview and Introduction GW100 Figure 42: Understanding OData XML - 2/4 The XML seen here has been shortened for clarity Figure 43: Understanding OData XML - 3/4 The XML seen here has been shortened for clarity 38 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData Figure 44: Understanding OData XML - 4/4 The XML seen here has been shortened for clarity Gateway and OData Figure 45: An OData Message Produced By a Gateway Server The above XML has been edited slightly in order for it to fit on the page 2012 © 2012 SAP AG. All rights reserved. 39 Unit 1: Gateway Overview and Introduction GW100 Figure 46: Obtaining OData Metadata The metadata description of an OData service is used by the SAP Gateway Consumption Tools when generating an OData proxy object in some language like Java or C#. Figure 47: SAP Extensions To OData Metadata 40 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData The Query Operation Figure 48: Entity Data Model - Overview Figure 49: Retrieving a Collection - ReadEntitySet Operation 1/3 2012 © 2012 SAP AG. All rights reserved. 41 Unit 1: Gateway Overview and Introduction GW100 Figure 50: Retrieving a Collection - ReadEntitySet Operation 2/3 Figure 51: Retrieving a Collection - ReadEntitySet Operation 3/3 42 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData Figure 52: Retrieving a Partial Collection - Filtering Figure 53: Retrieving a Partial Collection - Paging The $top command specifies how many entries are to be returned. Unless used in conjunction with the $skip command, these entries are always taken from the top of the collection. The $skip command omits the specified number of entries starting from the top of the collection. By using both $top and $skip together, you can implement paging. View the first page by showing only the top 10 entries. View the second page by skipping the first 10 entries and showing only the next 10. 2012 © 2012 SAP AG. All rights reserved. 43 Unit 1: Gateway Overview and Introduction GW100 View the third page by skipping the first 20 entries and showing only the next 10. The OData website contains more information on this topic. The READ Operation Figure 54: Retrieving a Single Entry - ReadEntity Operation 1/2 The syntax for reading a single entity from a collection is provided with the first <link> element found within an <atom:entry rel="nofollow"> element. Figure 55: Retrieving a Single Entry - ReadEntity Operation 2/2 Notice that the syntax for defining the element to be read is not the normal query string syntax. Instead you must create what is called a “Key Predicate”. This is a comma-separated list of name/value pairs enclosed within parentheses. 44 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData Any non-numeric value within a key predicate must be given as a quoted string. Figure 56: XML Returned by ReadEntitySet and ReadEntity - 1/2 A QUERY operation will return zero or more entries. Therefore, the XML will always be enclosed within an <atom:feed rel="nofollow"> element. If the QUERY operation locates an entries, these are supplied within <atom:entry rel="nofollow"> elements inside the <atom:feed rel="nofollow"> element. Figure 57: XML Returned by ReadEntitySet and ReadEntity - 2/2 If a READ operation is performed, then at most, a single entry will be returned. Therefore, the XML will be supplied as a single <atom:entry rel="nofollow"> element – even if zero entries are found. 2012 © 2012 SAP AG. All rights reserved. 45 Unit 1: Gateway Overview and Introduction GW100 Mapping OData Properties to Atom Elements Figure 58: Standard ATOM Elements - 1/2 Figure 59: Standard ATOM Elements - 2/2 46 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData Figure 60: Mapping OData Properties to ATOM Elements - 1/2 Figure 61: Mapping OData Properties to ATOM Elements - 2/2 2012 © 2012 SAP AG. All rights reserved. 47 Unit 1: Gateway Overview and Introduction GW100 OData in Practice Figure 62: Atom and OData Terminology The OData and Atom standards use different terminology to describe the same objects. These terms can be used interchangeably; however, in the XML, the Atom terminology is used, and within the ABAP coding used for creating custom Gateway services, the OData terminology is used. Figure 63: Displaying Atom XML in your Browser MIME stands for “Multipurpose Internet Mail Extension”. Its use has grown far beyond the original concept of extending emails to support content in non-ASCII character sets, binary attachments and multi-part messages. Now, the MIME type is universally used to identify the type of content being supplied to the client. The client then examines the MIME type and determines how that content should be processed. 48 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData Figure 64: A Quirk in Firefox When Displaying XML - 1/2 Figure 65: A Quirk in Firefox When Displaying XML - 2/2 2012 © 2012 SAP AG. All rights reserved. 49 Unit 1: Gateway Overview and Introduction 50 © 2012 SAP AG. All rights reserved. GW100 2012 GW100 Lesson: Introduction to OData Exercise 1: Getting Started with OData Exercise Objectives After completing this exercise, you will be able to: • Investigate OData information supplied by a Gateway service Business Example You wish to perform an initial investigation on how consume a business service provided by a backend business system through an OData interface. These exercises are designed to help you become familiar with OData XML. Therefore, you will need to use a browser that does not format the OData response, but instead, shows you the raw XML. You should not use Firefox or Safari for these exercises because they automatically format the response; instead, you should use either Internet Explorer or Chrome. Task: 1. First Steps With OData In this exercise you will examine the basic structure of an OData Service Document. Question: Using nothing more than the relative URLs supplied in the OData XML, how could we obtain a list of all flights that depart from a certain airport? Answer: Do the next exercise! :-) 2. Using OData Links In this exercise you will become familiar with the use of OData navigation links. 3. OData Metadata In this exercise, you will start to become familiar with the metadata supplied by an OData service. 2012 © 2012 SAP AG. All rights reserved. 51 Unit 1: Gateway Overview and Introduction GW100 Solution 1: Getting Started with OData Task: 1. First Steps With OData In this exercise you will examine the basic structure of an OData Service Document. Question: Using nothing more than the relative URLs supplied in the OData XML, how could we obtain a list of all flights that depart from a certain airport? Answer: Do the next exercise! :-) a) Open a browser and display the Service Document for the FlightInfomation service on the public SAP NetWeaver Gateway Server. The URL is: http://gw.esworkplace.sap.com/sap/opu/odata/sap/FlightInformation/ You will be asked for a user id and password: User: gwdemo Password: DEMO4GW You should see some XML like the following: <?xml version="1.0" encoding="utf-8" standalone="yes" ?> <app:service xmlns:app="http://www.w3.org/2007/app" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:m="http://schemas.microsoft.com/ado/2007/08/ dataservices/metadata" xmlns:sap="http://www.sap.com/Protocols/SAPData" xml:base="http://gw.esworkplace.sap.com:80/sap/opu/ odata/sap/FlightInformation/" rel="nofollow"> <app:workspace rel="nofollow"> <atom:title rel="nofollow">Data</atom:title> <app:collection sap:content-version="1" href="Flights" rel="nofollow"> <atom:title rel="nofollow">Flights</atom:title> <sap:member-title>Flight</sap:member-title> </app:collection> <app:collection sap:content-version="1" href="Bookings" rel="nofollow"> <atom:title rel="nofollow">Bookings</atom:title> <sap:member-title>Booking</sap:member-title> </app:collection> <app:collection sap:content-version="1" href="Airports" rel="nofollow"> <atom:title rel="nofollow">Airports</atom:title> <sap:member-title>Airport</sap:member-title> Continued on next page 52 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData </app:collection> </app:workspace> </app:service> b) Look in the root <app:service element rel="nofollow">. The service’s base URL is shown here in the xml:base parameter. c) Now display the “Airports” collection. To do this, locate this collection’s relative URL and append it the base URL to construct the URL for this collection. d) Now repeat step c), but this time for the “Flights” collection. e) Question: Using nothing more than the relative URLs supplied in the OData XML, how could we obtain a list of all flights that depart from a certain airport? Answer: Do the next exercise! :-) 2. Using OData Links In this exercise you will become familiar with the use of OData navigation links. a) Display the contents of the “Airports” collection. b) Within the Atom <atom:feed rel="nofollow"> element returned for this collection, you will see multiple <atom:entry rel="nofollow"> elements. Select an <atom:entry rel="nofollow"> element and within it, look for the <atom:link rel="nofollow"> elements. c) Locate the href parameter belonging to the first <atom:link rel="nofollow"> element. This is always a self-reference that identifies the current entry. Modify the URL in the browser’s address line so that only this single entry is returned. d) You should now see a single <atom:entry rel="nofollow"> element describing that one airport. E.G. Here is the entry for Frankfurt airport: <?xml version="1.0" encoding="utf-8" standalone="yes" ?> <atom:entry xml:base="http://GW.ESWORKPLACE.SAP.COM:80/sap/opu/odata/sap/ FlightInformation/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/ metadata" rel="nofollow"> <atom:category term="FlightInformation.Airport" Continued on next page 2012 © 2012 SAP AG. All rights reserved. 53 Unit 1: Gateway Overview and Introduction GW100 scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/ scheme"/> <atom:content type="application/xml" rel="nofollow"> <m:properties> <d:GeoCoordinates m:type="FlightInformation.GeoCoordinates"> <d:Longitude>-8.5666666666666664E00</d:Longitude> <d:Latitude>5.0016666666666666E01</d:Latitude> </d:GeoCoordinates> <d:IATACode>FRA</d:IATACode> <d:Name>FRANKFURT</d:Name> <d:URL>http://www.frankfurt-airport.com/content/ frankfurt_airport/en.html</d:URL> </m:properties> </atom:content> <atom:id rel="nofollow"> http://GW.ESWORKPLACE.SAP.COM:80/.../FlightInformation/ Airports('FRA') </atom:id> <atom:link href="Airports('FRA')" rel="edit" title="Airport"/> <atom:link href="Airports('FRA')/AirportsTo" rel="http://schemas.microsoft.com/ado/2007/08/dataservices/ related/AirportsTo" type="application/atom+xml;type=feed" title="AirportsTo"/> <atom:link href="Airports('FRA')/DepartingFlights" rel="http://schemas.microsoft.com/…/dataservices/related/ DepartingFlights" type="application/atom+xml;type=feed" title="DepartingFlights"/> <atom:title type="text" rel="nofollow">FRANKFURT - FRA</atom:title> <atom:updated rel="nofollow">2012-01-30T12:36:14Z</atom:updated> </atom:entry> e) Within the <atom:content rel="nofollow"> element you will see an <m:properties> element. What properties does an Airport have? ___________________________________________________________ Are these properties all simple types? ___________________________________________________________ f) Locate the href parameters of the second and third <atom:link rel="nofollow"> elements. Judging by the value of the title parameter for each link, what type of information would you say these links return? Continued on next page 54 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData ___________________________________________________________ ___________________________________________________________ g) In the browser’s address line, issue the URL derived from the value of the third link <atom:link rel="nofollow"> parameter (called DepartingFlights). h) You are now looking at a list of all the flights that depart from the selected airport. i) Question: From a business perspective, what have you been doing here? (And don’t say “Following hypertext links”) Answer: The FlightInformation data model that sits behind this OData interface has defined within it, multiple entity types such as “Flight” and “Airport”. These entity types are associated with each other, and these associations are implemented by means of “navigation links”. From a business perspective, a navigation link allows a user to walk through the data in the data model without needing to calculate how to take the next step. This is an example of the HATEOS principle at work and brings significant ease of use to the end user. 3. OData Metadata In this exercise, you will start to become familiar with the metadata supplied by an OData service. a) From your browser’s address line, issue the OData service’s base URL again, but this time append the command $metadata. You should see quite a large amount of XML that looks similar to this: <?xml version="1.0" encoding="utf-8" ?> <edmx:Edmx Version="1.0"> <edmx:DataServices m:DataServiceVersion="2.0"> <Schema Namespace="flightinformation"> <EntityType Name="Booking" sap:content-version="1"> <Key> <PropertyRef Name="AirlineId"/> <PropertyRef Name="ConnectionNo"/> <PropertyRef Name="FlightDate"/> <PropertyRef Name="BookingId"/> </Key> <Property Name="AirlineId" Type="Edm.String" Continued on next page 2012 © 2012 SAP AG. All rights reserved. 55 Unit 1: Gateway Overview and Introduction GW100 Nullable="false" MaxLength="3" sap:label="Airline"/> <Property Name="ConnectionNo" Type="Edm.String" Nullable="false" MaxLength="4" sap:label="Flight Number"/> <Property Name="FlightDate" Type="Edm.DateTime" Nullable="false" sap:label="Date"/> <Property Name="BookingId" Type="Edm.String" Nullable="false" MaxLength="8" sap:label="Booking number"/> <Property Name="CustomerNo" Type="Edm.String" MaxLength="8" sap:label="Customer Number"/> <Property Name="CustomerName" Type="Edm.String" MaxLength="25" m:FC_TargetPath="SyndicationAuthorName" m:FC_KeepInContent="true" sap:label="Passenger Name"/> <Property Name="Price" Type="Edm.Decimal" Precision="15" Scale="2" sap:label="Airfare"/> <Property Name="CurrencyCode" Type="Edm.String" MaxLength="5"sap:label="Airline Currency" sap:semantics="currency-code"/> <Property Name="BookingDate" Type="Edm.DateTime" sap:label="Booking date"/> <Property Name="Agency" Type="Edm.String" MaxLength="8" sap:label="Agency No."/> <Property Name="Cancelled" Type="Edm.String" MaxLength="1" sap:label="Cancelation flag"/> <Property Name="Title" Type="Edm.String" m:FC_TargetPath="SyndicationTitle" m:FC_KeepInContent="false"/> </EntityType> ...snip... </Schema> </edmx:DataServices> </edmx:Edmx> b) The <EntityType> element for “Airport” has multiple properties, but only one of those properties (“IATACode”) has been defined as a key field. An OData entity type is exactly the same as an ABAP dictionary structure, and the entity set (or collection) formed from multiple instances of the entity type is exactly the same as a database table definition. c) 56 Look at the metadata describing the Airport entity type. There are 5 properties, one of which is nominated to be the key. Continued on next page © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData There are also 2 <NavigationProperty> elements. These two <NavigationProperty> elements define the ability for a user to see, for instance, all the flights that leave from any particular airport. But how is this relationship defined? Are the entity types directly related to each other in the navigation property? ___________________________________________________________ Is some other definition used in the declaration of the Navigation Property? ___________________________________________________________ d) The <NavigationProperty> element within the Airport <EntityType> refers to two roles. Where are these defined? Hint: Look further down the XML at the <Association rel="nofollow"> elements. Locate the correct <Association rel="nofollow"> element referred to by the <NavigationProperty> and inside it, you will find two <End> elements. Each <End> element gives a name to the association (specified by the role parameter), the entity type involved in the association and the cardinality (or multiplicity) as seen from that end of the relationship. e) Continue looking down the XML until you see a group of <EntitySet> elements. An <EntitySet> element defines the name of the aggregation formed from a particular entity type. Here is where the existence of a collection is declared. E.G. An aggregation called “Airports” is formed from the entity type “flightinformation.Airport”. (An entity type is referenced using its fully qualified name). Generally, the entity set name will simply be the plural of the entity type name, but this is only a convenience for the end user, not a semantic requirement. Collections created automatically usually have the word “Collection” appended to the entity type name. Also, you may often see the term “Collection” used in place of “Entity Set” and the term “Entry” used in place of “Entity”. These terms are interchangeable. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 57 Unit 1: Gateway Overview and Introduction GW100 The terms “Collection” and “Entry” belong to Atom terminology, whereas the terms “EntitySet” and “Entity” belong to OData terminology. f) Now look further down the XML and locate the <AssociationSet rel="nofollow"> elements. The difference here is that an <Association rel="nofollow"> element declares that two entity types are related, but an <AssociationSet rel="nofollow"> element declares that two entity sets are related. You should now have a good working understanding of the XML used to communicate an OData message and also the XML used to describe an OData message (i.e. the metadata). 58 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Introduction to OData Lesson Summary You should now be able to: • Understand the architecture of the Atom and OData protocols. • Understand how SAP NetWeaver Gateway makes use of OData. • Understand how to issue read-only OData requests from your browser. 2012 © 2012 SAP AG. All rights reserved. 59 Unit Summary GW100 Unit Summary You should now be able to: • Understand the high-level architecture of SAP NetWeaver Gateway • Understand the different deployment and development scenarios • Understand the different development options for creating Gateway Services and consuming Gateway Services • Understand what Representational State Transfer (REST) is. • Understand how REST has been implemented as HTTP(S). • Understand the architecture of the Atom and OData protocols. • Understand how SAP NetWeaver Gateway makes use of OData. • Understand how to issue read-only OData requests from your browser. 60 © 2012 SAP AG. All rights reserved. 2012 Unit 2 Gateway Data Model Generator Unit Overview In this unit, you will learn how to create a Gateway service using the generator tool. This process requires no knowledge of the ABAP programming language; however, it does require the user to have a good understanding of the business process being delivered. You will start by creating a Gateway service that offers read-only capabilities, then you will add update and create capabilities. Unit Objectives After completing this unit, you will be able to: • • • • • • Create a read-only Gateway Service based on a Remote Function Module or an Object in the Business Object Repository (BOR). Expose a Gateway Service for consumption. Test your Gateway Service from a browser. Extend an existing RFM or BOR based Gateway Service to include update functionality. Understand the danger posed by Cross-Site Request Forgery attacks and how the SAP NetWeaver Gateway Server prevents them. Test the new functionality of your Gateway Service from a browser. Unit Contents Lesson: Generating Data Model for Read .................................... 62 Procedure: Generate a Gateway Data Model ........................... 65 Exercise 2: Generate a Read-Only Gateway Service .................. 83 Lesson: Generating Data Model for Update.................................100 Procedure: Change a Gateway Data Model ............................101 Exercise 3: Extend a Generated Gateway Service to Include Update Functionality ................................................................. 115 2012 © 2012 SAP AG. All rights reserved. 61 Unit 2: Gateway Data Model Generator GW100 Lesson: Generating Data Model for Read Lesson Overview This lesson covers: • • • Create a read-only Gateway Service based on a Remote Function Module or an Object in the Business Object Repository (BOR) Expose a Gateway Service for consumption Test your Gateway Service from a browser Lesson Objectives After completing this lesson, you will be able to: • • • Create a read-only Gateway Service based on a Remote Function Module or an Object in the Business Object Repository (BOR). Expose a Gateway Service for consumption. Test your Gateway Service from a browser. Business Example Remote Function Calls and Business Object Repository Overview Figure 66: Overview - Remote Function Modules 62 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 67: Overview - Business Object Repository (BOR) The Modelling Wizard Figure 68: Gateway Data and Consumption Models - 2/2 2012 © 2012 SAP AG. All rights reserved. 63 Unit 2: Gateway Data Model Generator GW100 Figure 69: Gateway Data Models Based on BOR Objects - Overview 64 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Generate a Gateway Data Model 1. Create a Gateway Data Model in the ABAP Development Workbench 2. Map your selected RFMs to Gateway Service operations using the Gateway Model Generator 3. Define the interface of the Gateway Service Operation based on the fields in the RFM 4. Generate the Gateway Data Model 5. Associate the Gateway Data Model with a Gateway Consumption Model 6. Associate the Gateway Service with a System Alias 7. Test your Gateway Service in a browser Gateway Data Model Figure 70: Step 1) Create A Gateway Data Model - 1/2 2012 © 2012 SAP AG. All rights reserved. 65 Unit 2: Gateway Data Model Generator GW100 Figure 71: Step 1) Create A Gateway Data Model - 2/2 Figure 72: Step 2) Map RFM to Gateway Service Operation - 3/4 66 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 73: Step 2) Map RFM to Gateway Service Operation - 4/4 Figure 74: Step 3.1) Define the QUERY Operation's Interface 2012 © 2012 SAP AG. All rights reserved. 67 Unit 2: Gateway Data Model Generator GW100 Figure 75: Step 3.2) Add Mandatory Fields to the Interface - 3/3 Figure 76: Step 3.2) Define Constant Values for Mandatory Fields - 3/3 68 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 77: Step 3.3) Remember Which Fields Hold Key Values Figure 78: Step 3.4) Define a Model Key 2012 © 2012 SAP AG. All rights reserved. 69 Unit 2: Gateway Data Model Generator GW100 Figure 79: Step 3.4) Map RFM Fields to the Model Key - 4/4 Figure 80: Step 2) A QUERY Operation On Its Own Is Not Sufficient 70 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 81: Step 2) Creating a READ Operation (Summary) - 3/3 Figure 82: Step 2.1) Define the Fields that Will Supply Key Data 2012 © 2012 SAP AG. All rights reserved. 71 Unit 2: Gateway Data Model Generator GW100 Figure 83: Step 2.2) Flattening the Interface - 1/3 Figure 84: Step 2.2) Flattening the Interface - 2/3 72 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 85: Step 2.2) Flattening the Interface - 3/3 Figure 86: Step 4) Generate the Data Model Runtime Classes 2012 © 2012 SAP AG. All rights reserved. 73 Unit 2: Gateway Data Model Generator GW100 Gateway Consumption Model Figure 87: Step 5) Gateway Consumption Model - Overview Figure 88: Step 5) Gateway Consumption Model - 1/3 74 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 89: Step 5) Gateway Consumption Model - 2/3 Figure 90: Step 5) Gateway Consumption Model - 3/3 2012 © 2012 SAP AG. All rights reserved. 75 Unit 2: Gateway Data Model Generator GW100 Gateway Service Figure 91: Step 6) Assign System Alias to Gateway Service Figure 92: Step 6.1) Locate Your Gateway Service 76 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 93: Step 6.2) Display Service Properties - 2/2 Figure 94: Step 6.3) Assign a System Alias - 2/2 2012 © 2012 SAP AG. All rights reserved. 77 Unit 2: Gateway Data Model Generator GW100 Test QUERY and READ Figure 95: Step 7) Test Your Gateway Service - Overview Figure 96: Step 7.1) Invoke Gateway Service From a Browser 78 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 97: Step 7.2) The Gateway Service Document - 1/2 Figure 98: Step 7.2) The Gateway Service Document - 2/2 Figure 99: Step 7.3) Testing the QUERY Operation - 1/5 2012 © 2012 SAP AG. All rights reserved. 79 Unit 2: Gateway Data Model Generator GW100 Figure 100: Step 7.3) Testing the QUERY Operation - 3/5 Figure 101: Step 7.3) Testing the QUERY Operation - 4/5 80 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 102: Step 7.3) Testing the QUERY Operation - 5/5 Figure 103: Step 7.4) Testing the READ Operation - 1/2 2012 © 2012 SAP AG. All rights reserved. 81 Unit 2: Gateway Data Model Generator GW100 Figure 104: Step 7.4) Testing the READ Operation - 2/2 82 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Exercise 2: Generate a Read-Only Gateway Service Exercise Objectives After completing this exercise, you will be able to: • Create a Gateway service providing read-only functionality. Business Example You need to provide a Gateway service that provides a Bank information lookup service. Log on to the Gateway training system using the userid and password supplied to you by your trainer. Whenever you need to create a new model or class, always append your group number to the name to ensure the name remains unique. All ABAP development is being done using the package $TMP (Local Object) Task: 1. Create a Gateway Data Model 2. Create a Gateway Consumption Model There are two ways to create a Gate Consumption Model. You can either create it as an independent object, which in a second step, is then assigned to the Data Model, or from within the Data Model itself, you can create and assign the Consumption Model in a single step. Here we will take the two-step approach. 3. Assign Data Model to Consumption Model 4. Assign System Alias to Gateway Service 5. Test the Gateway Service in a Browser 6. Correct the Data Model Configuration To discover the error, we must look back at our Data Model definition. 7. Performing a READ Operation So far, all we have done is to build a faulty Gateway Service and then correct it. This service has two operations, QUERY and READ, but up till now, we have used only the QUERY operation. 2012 © 2012 SAP AG. All rights reserved. 83 Unit 2: Gateway Data Model Generator GW100 Solution 2: Generate a Read-Only Gateway Service Task: 1. Create a Gateway Data Model a) Run transaction SE80 (ABAP Development Workbench) b) Select “GW Data Model” from the drop-down list and enter the name of a new Data Model. The name will be Z_GW100_RFM_BANK_<nn> where nn is your group number. Figure 105: Data Model c) After confirming that you want to create a new object, enter the Data Model name, a Type of “PS” and select the “Generate from Data Source Object” radio button. d) Do not switch off the “OData Channel” checkbox. If you do, the Gateway Service will be generated using the older Generic Channel class hierarchy, which will create several problems: 1. The rest of the instructions in this document will not function correctly. Continued on next page 84 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read 2. e) None of the newer debugging facilities will be available to you. On the next pop-up screen, enter the following values: • A description such as “GW100 Bank Demo – Group nn” • A Data Source Type of “2 Remote Function Calls” • A System Alias of LOCAL f) Save all your objects as Local Objects ($TMP). g) SE80 will now take you to the Gateway Modelling Tool. Here use the Binoculars button to search for the Bank related BAPIs. Use the search patter BAPI*BANK*. h) Select BAPI_BANK_GETLIST and then click the Create Mapping button on the right side of the screen . i) Select “Query” from the Operation Type drop down menu and then press the green tick icon at the bottom right of the screen . j) Your data model interface now contains the fields supplied by the BAPI_BANK_GETLIST function module. We must now nominate which of those fields define the model’s key. Right click on BANK_CTRY and set it as a key field. Repeat this process for field BANK_KEY Figure 106: BANK_KEY Continued on next page 2012 © 2012 SAP AG. All rights reserved. 85 Unit 2: Gateway Data Model Generator GW100 k) From the search results list on the left, select BAPI_BANK_GETDETAIL and press Create Mapping. l) Select an Operation Type of Read and uncheck the BANK_DETAIL and RETURN data structures. We will not be using these. m) Right click on BANKCOUNTRY and select “Change Mapping Route”. Caution: Remember: right clicking on the field selects it without switching off the selection check box. n) Map BANKCOUNTRY to the model key field BANK_CTRY o) Map BANKKEY to the model key field BANK_KEY p) Now the BANK_ADDRESS data structure needs to be flattened. To do this, right click on each field in the BANK_ADDRESS data structure (apart from BANK_NAME and CITY) and press “Change Mapping Route”. q) In the Change Mapping Route pop-up, select the root node of the OData Service interface. Figure 107: Change Mapping Route r) After each property of the BANK_ADDRESS structure has been reassigned to the root node of the OData Service’s interface, your mapping structure will look like this. Continued on next page 86 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 108: Mapping Structure s) Now generate your Data Model. Figure 109: Data Model You should now see a list of the generated model classes. Figure 110: Generated Model Classes Continued on next page 2012 © 2012 SAP AG. All rights reserved. 87 Unit 2: Gateway Data Model Generator t) GW100 Press F3 or Back on the toolbar to return to the SE80 screen. In the name field underneath “GW Data Model” you will see the name of the generated data model. Copy this value into the clipboard, as you will need it in the following step. Figure 111: GW Data Model 2. Create a Gateway Consumption Model There are two ways to create a Gate Consumption Model. You can either create it as an independent object, which in a second step, is then assigned to the Data Model, or from within the Data Model itself, you can create and assign the Consumption Model in a single step. Continued on next page 88 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Here we will take the two-step approach. a) From the drop down menu in which “GW Data Model” is displayed, select “GW Consumption Model”. Enter a name of Z_GW100_BANK_CM_nn where CM indicates “consumption model” and nn is your group number. Press enter to create this new model. b) Whatever name you enter into the “Service Technical Name” field will become the Gateway Service name used by an external consumer. Therefore, don’t use an ABAP class name or some other internal value. So choose the name carefully – it should be relevant and meaningful to someone with no knowledge of an SAP system. Figure 112: Consumption Model Do not switch off the “OData Channel” checkbox! If you do, your consumption model will use the old Generic Channel runtime, thus making it incompatible with the Data Model we just created, which uses the OData Channel runtime. Due to the fact that we are using a generated service in a training environment, certain constraints are in operation here. In our case, the service name must start with a Z because we are using customer namespace, and secondly, to avoid name collisions with the services created by other students, we must add a group number to the end of the name. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 89 Unit 2: Gateway Data Model Generator 3. GW100 Assign Data Model to Consumption Model a) Once the Consumption Model has been created, the Data Model needs to be assigned to it. Right click on the consumption model name and select “Add GW Data Model”. Now paste in the name of the data model you copied in section 1, step 19. Figure 113: GW Data Model 1/2 b) Once the Data Model has been assigned, your Consumption Model will look like this. Figure 114: GW Data Model 2/2 4. Assign System Alias to Gateway Service a) The Gateway Service is not quite ready to execute yet. The last step is to assign a System Alias to the Gateway Service. b) Start transaction /IWFND/MAINT_SERVICE. Here you will see a list of all Services known to this Gateway server. c) Click the column header for “External Service Name” and sort the table. This will help you locate you service faster. Continued on next page 90 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 115: Service Catalog d) Select your service in the table and examine the properties in the lower two panes. Figure 116: ICF Nodes The pane on the left shows that a node in the ICF has been created, but the pane on the right shows that the Gateway Service does not yet have a system alias assigned to it. e) Click the “Add System Alias” and in the next screen click “New Entries”. f) You now need to enter the name of the “Service Document Identifier”. This name is the external service name followed by the version number. So using the name defined in step 21, this will be Z_BANK_INFO_nn_0001 (where nn is your group number). Figure 117: Added Entries g) Save your changes and return to the /IWFND/MAINT_SERVICE screen. h) You service now has a System Alias assigned. Figure 118: ICF Nodes 5. Test the Gateway Service in a Browser Continued on next page 2012 © 2012 SAP AG. All rights reserved. 91 Unit 2: Gateway Data Model Generator GW100 a) Test the service by pressing the “Call Browser” button. b) You will be asked to provide your userid and password in order to run the Gateway Service. Figure 119: Gateway Service in a Browser c) The Gateway Service Document will now be displayed Figure 120: Gateway Service Document d) Look at href parameter of the <app:collection rel="nofollow"> element in the returned XML. The Bank collection name is z_gw100_rfm_bank_01Collection. Notice that the uppercase service name used in the SAP system has been translated to lower case here and used to form the collection name. Continued on next page 92 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read In the browser’s address line, add the collection name to the end of the Service Document’s URL and press enter. Figure 121: Gateway Service Document e) This error should not be surprising, because we know that the function module BAPI_BANK_GETLIST has BANK_CTRY as a mandatory input field and we have made no attempt to supply the required value – so it blows up in our face. Before we add the $filter parameter needed to pass in a value for BANK_CTRY, we must first check what name this required input parameter has in the OData interface. This is important because all collection and field names in OData are case-sensitive. To do this, remove the collection name from the URL and replace it with the $metadata command and press enter. Figure 122: Gateway Service Document f) In the <Key> element, we can see that two fields are defined. From our knowledge of the business case, we know that for the QUERY operation, only bank_ctry is needed. The other field, bank_key, is a key field, but is needed only for the READ operation. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 93 Unit 2: Gateway Data Model Generator GW100 In the URL in the browser’s address line, remove $metadata and replace it with a query string containing the $filter command and press enter. /z_bank_info_01/z_gw100_rfm_bank_01Collection? $filter=bank_ctry eq 'US' Caution: • • • • • g) The $filter command is a normal URL query string parameter; therefore, if this is the first value in the query string, you must start with a “?” question mark character; or, if this is a subsequent query string parameter, you must use the “&” ampersand separator character. The field name bank_ctry is case-sensitive. The operator (eq, gt, lt, ne etc) must be specified in lower case. The operator must have a space character or %20 on either side. Any non-numeric value must be enclosed in single quotes. If you are copying and pasting the string from a formatted document, make sure that the straight quote character ' has not been substituted for the “smart” quotes ‘ and ’. This is not what we were hoping for! Figure 123: Gateway Service Document Why has this request failed? Keep this browser window open – we will need to refresh it after correcting the error. 6. Correct the Data Model Configuration Continued on next page 94 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read To discover the error, we must look back at our Data Model definition. a) Rerun transaction SE80. b) Select “GW Data Model” and your Data Model name should reappear in the input field. Press enter to display this object. If the name does not reappear, then you can construct it using the following <Model Identifier>_<version>_<type> <Model Identifier> will be Z_GW100_RFM_BANK_nn <version> is always 0001 <type> is PS c) Double click on the Data Model name in the hierarchy view and then press the Gear icon that appears in the tool bar . d) Switch into Change Mode, select the QUERY operation on the right side of the screen and then press Change Mapping. e) Notice that the BANK_CTRY field has no mapping route assigned? This means that this particular field has not been added to the OData Service’s interface. So even though we know it is a key field and have attempted to assign a value to it using the $filter command in the URL, all such attempts will fail because this field does not exist in the interface. Right click on BANK_CTRY to select it and press the “Change Mapping Route” button. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 95 Unit 2: Gateway Data Model Generator GW100 Figure 124: BANK_CTRY f) Map the BANK_CTRY RFM field to the BANK_CTRY key field in the Data Model and press the green tick to save the changes. Figure 125: BANK_CTRY RFM g) Regenerate the Data Model. h) Return to your browser and press refresh. Et voila! Continued on next page 96 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Figure 126: Gateway Service Document 7. Performing a READ Operation So far, all we have done is to build a faulty Gateway Service and then correct it. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 97 Unit 2: Gateway Data Model Generator GW100 This service has two operations, QUERY and READ, but up till now, we have used only the QUERY operation. a) Look at the XML generated from the above successful QUERY operation. Inside each <atom:entry rel="nofollow"> element, towards the end, you will an <atom:id rel="nofollow"> element. This element is a self reference to the current <atom:entry rel="nofollow">. Select the contents of this element and paste it into the browser’s address line. b) Simply by specifying the exact parameters needed to identify a single bank, you have implicitly instructed the Gateway Service to perform a READ operation instead of the QUERY operation. Figure 127: Gateway Service Document c) Notice the difference in the XML returned by the QUERY and READ operations. When you perform a QUERY operation, you will receive zero or more Atom entries; but when you perform a READ operation, you will receive zero or one entry. This difference means that not many how many or few entries a QUERY operation returns, the results will always be container within an <atom:feed rel="nofollow"> element. In contrast, the READ operation will only ever return a single <atom:entry rel="nofollow"> element – even if it has no contents. This completes the exercise on creating and testing a read-only Gateway Service using the Generator Tools. 98 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Read Lesson Summary You should now be able to: • Create a read-only Gateway Service based on a Remote Function Module or an Object in the Business Object Repository (BOR). • Expose a Gateway Service for consumption. • Test your Gateway Service from a browser. 2012 © 2012 SAP AG. All rights reserved. 99 Unit 2: Gateway Data Model Generator GW100 Lesson: Generating Data Model for Update Lesson Overview This lesson covers: • • • Extend an existing RFM or BOR based Gateway Service to include update functionality Understand the danger posed by web-based attacks (CSRF) and how the SAP NetWeaver Gateway Server prevents them Test the new functionality of your Gateway Service from a browser Lesson Objectives After completing this lesson, you will be able to: • • • Extend an existing RFM or BOR based Gateway Service to include update functionality. Understand the danger posed by Cross-Site Request Forgery attacks and how the SAP NetWeaver Gateway Server prevents them. Test the new functionality of your Gateway Service from a browser. Business Example 100 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Change a Gateway Data Model 1. Edit the existing GW Data Model (SE80) 2. Search for the RFMs to implement the missing operations 3. Bind each RFM to the required operation and define the interface 1. 2. Ensure that all key values are mapped correctly All data structures have been flattened 4. Regenerate the service 5. Protect Web Application from attack 6. Test the UPDATE service 7. Test the CREATE service Change Generated Gateway Service Figure 128: Step 1) Edit the Existing GW Data Model - 1/2 2012 © 2012 SAP AG. All rights reserved. 101 Unit 2: Gateway Data Model Generator GW100 Figure 129: Step 1) Edit the Existing GW Data Model - 2/2 Figure 130: Step 2) Locate Required RFMs Figure 131: Step 3) Map RFM(s) to OData Operation(s) 102 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Figure 132: Step 3.1) Check Key Field Mapping - UPDATE 2/2 Figure 133: Step 3.2) Map Structured Fields to Root Node - UPDATE 2012 © 2012 SAP AG. All rights reserved. 103 Unit 2: Gateway Data Model Generator GW100 Figure 134: Step 3.1) Check Key Field Mapping - CREATE Figure 135: Step 3.2) Map Structured Fields to Root Node - CREATE Figure 136: Step 4) Regenerate the Service 104 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Cross-Site Request Forgery Attacks At this point, we must take a digression away from the Gateway development process in order to understand how to protect web-based applications from attack. Whenever a web-based application is run, certain levels of trust are set up between the user and the webserver with which they are interacting. There are two attacks that both work by exploiting this trust relationship… Figure 137: Cross-Site Scripting Attacks - 1/2 Figure 138: Cross-Site Scripting Attacks - 2/2 2012 © 2012 SAP AG. All rights reserved. 105 Unit 2: Gateway Data Model Generator GW100 Figure 139: Cross-Site Request Forgery Attacks - 1/2 Figure 140: Cross-Site Request Forgery Attacks - 2/2 CSRF attacks can be prevented by sending any non-guessable value (known as a token) to the user once they have logged on. The token is stored as a cookie and must be returned in all subsequent requests. The attacker can deduce that such a token is required, but cannot possibly know the token’s value because the coding to generate the fraudulent request executes on the hacker’s webserver – where it has no access to the browser’s cookies. 106 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Figure 141: Summary of Web Attacks Test the UPDATE Service Figure 142: Steps 6 and 7 Testing UPDATE & CREATE Services - Tools Figure 143: Step 6) Testing the UPDATE Service - Summary 2012 © 2012 SAP AG. All rights reserved. 107 Unit 2: Gateway Data Model Generator GW100 Figure 144: Step 6.1) GET the XML By Using a READ Operation - 1/2 Figure 145: Step 6.1) GET the XML By Using a READ Operation - 2/2 108 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Figure 146: Step 6.2) Adjust the OData XML - 1/3 Figure 147: Step 6.2) Adjust the OData XML - 2/3 2012 © 2012 SAP AG. All rights reserved. 109 Unit 2: Gateway Data Model Generator GW100 Figure 148: Step 6.2) Adjust the OData XML - 3/3 Figure 149: Step 6.3) Add HTTP Header Field X-CSRF-Token - 1/3 110 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Figure 150: Step 6.3) Add HTTP Header Field X-CSRF-Token - 2/3 Figure 151: Step 6.3) Add HTTP Header Field X-CSRF-Token - 3/3 2012 © 2012 SAP AG. All rights reserved. 111 Unit 2: Gateway Data Model Generator GW100 Figure 152: Step 6.4) Add HTTP Header Field Content-Type Figure 153: Step 6.5) Send Modified XML Back to the Server Figure 154: Step 6.6) Reissue the READ Request 112 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Test the CREATE Service Figure 155: Step 7) Testing the CREATE Service - Summary Figure 156: Step 7.1) Use the HTTP Method POST Figure 157: Step 7.2) Remove the Key Predicate From the URL 2012 © 2012 SAP AG. All rights reserved. 113 Unit 2: Gateway Data Model Generator GW100 Figure 158: Step 7.3) Supply Unique Key Values Figure 159: Step 7.4) HTTP 201 Created 114 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Exercise 3: Extend a Generated Gateway Service to Include Update Functionality Exercise Objectives After completing this exercise, you will be able to: • Extend the Gateway service created in the previous exercise to include create and update functionality. Business Example You need to provide a Gateway service that provides not only Bank look up information, but allows users to create and edit Bank information. Log on to the Gateway training system using the userid and password supplied to you by your trainer. Whenever you need to create a new model or class, always append your group number to the name to ensure the name remains unique. All ABAP development is being done using the package $TMP (Local Object) In order to complete this exercise, you must first have successfully completed Exercise 2 – Generating a Read-Only Gateway Service. Testing the functionality added in this exercise will be performed using the RESTClient add-on installed in the Firefox browser. Task: 2012 1. Edit Your Existing Gateway Data Model 2. Get UPDATE XML using a READ Operation 3. Prepare the UPDATE Operation 4. Prepare the CREATE Operation © 2012 SAP AG. All rights reserved. 115 Unit 2: Gateway Data Model Generator GW100 Solution 3: Extend a Generated Gateway Service to Include Update Functionality Task: 1. Edit Your Existing Gateway Data Model a) Run transaction SE80 (ABAP Development Workbench) b) Select “GW Data Model” from the drop-down list and the name of your Data Model should appear in the input field. If it does not, you can construct the name using the following pattern: Z_GW100_RFM_BANK_<nn>_0001_PS where <nn> is your group number. c) When the object hierarchy is displayed, double click on the root node (the GW Data Model name). This will display the Data Model’s properties on the right side of the screen. In addition to showing the object’s properties, a “gear wheel” icon will appear in the toolbar. Clicking this will take you to the Gateway Mapping Service Tool. Figure 160: Gear Wheel Icon d) Switch to change mode. e) Press the binoculars icon and search for BAPI*BANK*. f) First, select the BAPI_BANK_CHANGE function module and click the Create Mapping toolbar button on the right side of the screen. Figure 161: Create Mapping Continued on next page 116 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update g) The mapping tool pop-up window now opens. Select “Update” from the drop down list. Figure 162: Update h) As soon as this selection is made, the mapping tool automatically exposes the RFM’s two key fields to the OData interface, but does so using their existing field names. However, we have already nominated the BANK_CTRY and BANK_KEY fields belonging to the QUERY and READ operations to be the Data Model’s key fields. Therefore, you must correct the mapping of these two fields to point to the model’s key fields: BANKCOUNTRY → BANK_CTRY BANKKEY → BANK_KEY The field mapping should now look like this Continued on next page 2012 © 2012 SAP AG. All rights reserved. 117 Unit 2: Gateway Data Model Generator GW100 Figure 163: Mapping Route Hint: Remember: right clicking on the field selects it without switching off the selection check box. i) Deselect all non-mandatory parameter fields and structures. The second check box column indicates whether a parameter is mandatory or not. j) When we created the READ operation, we needed to map each field in the BANK_ADDRESS data structure to the Data Model’s root node. Without this step, we would have had to make a second HTTP request in order to retrieve the data within this data structure. The normal sequence of processing steps is that a user will first perform a READ operation, modify the data, and then perform an UPDATE operation. In order to allow the data coming out of the READ operation to be passed into the UPDATE operation, we must ensure that the BANK_ADDRESS fields belonging to the input side of BAPI_BANK_CHANGE are mapped to the same Data Model fields that the READ operation populates. For each field in the BAPI_BANK_CHANGE’s input data BANK_ADDRESS do the following: 1. 2. 3. 4. Right click on the field name to select it without switching off the selection checkbox. Click “Change Mapping Route” In the pop-up window, map the RFM field to the corresponding Data Model field name directly under the root node. Press the green tick icon in the bottom right of the screen to complete the mapping. Your mapping screen should now look like this: Continued on next page 118 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Figure 164: Mapping k) From the list of function modules on the left of the screen, select BAPI_BANK_CREATE, press the Create Mapping button and map it to the Create operation. l) Repeat the mapping process described above, being careful to check that: 1. 2. 3. 4. The input fields BANK_CTRY and BANK_KEY are mapped to the model key fields of the same name. All the fields in the BANK_ADDRESS input structure are mapped to the model fields below to the root node. The output fields BANKCOUNTRY and BANKKEY are mapped to the data model directly under the root node. These fields are not used in our scenario, but since they contain the key values of the Bank we have just created, should be kept for the sake of completeness. All other non-mandatory RFM interface fields are deselected. Your mapping screen should now look like this: Continued on next page 2012 © 2012 SAP AG. All rights reserved. 119 Unit 2: Gateway Data Model Generator GW100 Figure 165: Mapping m) 2. Generate the model. Get UPDATE XML using a READ Operation a) In the SE80 display of your GW Data Model, expand the “Related GW Consumption Models” branch and double click on the consumption model name. b) In the properties view to the right, copy the service document URL to the clipboard. Figure 166: Service Document URL c) Start Firefox and paste your Gateway Service Document URL into the address line. Edit the URL to perform a QUERY request (i.e. display the collection of banks). Continued on next page 120 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update d) Choose a bank from the collection and copy the URL in its <atom:id rel="nofollow"> tab into the clipboard. This is the URL for a READ request of that particular bank. e) Start the RESTClient from the Tools menu in Firefox. A new tab will open. Figure 167: RESTClient f) Paste the URL for the READ request into the RESTClient’s Address line and add the query string ?sap-ds-debug=true. g) Press the “Add Request Header” button in the RESTClient toolbar. h) Add the variable name X-CSRF-Token and a value of Fetch. Neither of these values are case sensitive. Figure 168: X-CSRF-Token / Fetch 3. i) Check that the HTTP method is set to GET and press Send. j) Copy the XML from the “Response Body” section at the bottom of the screen to the “Request Body” in the centre of the screen. Prepare the UPDATE Operation a) Since the previous READ request was issued with the query string parameter sap-ds-debug=true, we received detailed debugging information. This can be seen by selecting the “Rendered HTML” section in the RESTClient and clicking on the SAP icon in the bottom right of the screen. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 121 Unit 2: Gateway Data Model Generator GW100 Figure 169: Rendered HTML b) Select the Response tab in the popup window. Figure 170: Response Tab Copy the x-csrf-token value to the clipboard. c) Close the debug popup window and double click on the word Fetch in the Response Header section. Paste in the x-csrf-token value. d) Add a new HTTP Header variable: Name: Content-Type Value: application/atom+xml;type=entry Continued on next page 122 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update e) Make sure that the query string parameter sap-ds-debug=true has been deleted from the URL. If you leave this query string parameter in the PUT request, the UPDATE operation will not succeed, but you will still receive an HTTP 200 OK status code in return. f) Change the HTTP Method to PUT. g) The XML returned from the READ operation cannot immediately be used for the UPDATE operation; it needs to be edited. The header line <?xml version="1.0" encoding="UTF-8"?> should be kept (but the UPDATE operation will succeed without it). h) The entire <atom:entry rel="nofollow"> element must be kept, including all the namespace parameters. <atom:entry xml:base="http://server:port/sap/opu/odata/sap/GWServiceName/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" rel="nofollow"> i) The <atom:category rel="nofollow"> tag can be deleted as it serves no purpose for an UPDATE operation. However, leaving in the XML will not cause any problems. j) The <atom:content rel="nofollow"> and <m:properties> tags start the elements that will contain all the bank details. These must not be removed. k) There now follows an element for each property belonging to a Bank. <d:street>1060 West Addison St</d:street> <d:bankcountry m:null="true"/> <d:bank_key>021800089</d:bank_key> <d:bank_ctry>US</d:bank_ctry> <d:swift_code>CITIUSXX</d:swift_code> <d:bank_no>021800089</d:bank_no> <d:pobk_curac m:null="true"/> <d:post_bank m:null="true"/> <d:city>Chicago</d:city> <d:bankkey m:null="true"/> <d:region>IL</d:region> <d:bank_branch>Hoosier St</d:bank_branch> <d:addr_no m:null="true"/> <d:bank_group m:null="true"/> <d:bank_name>Bank of the Blues Brothers</d:bank_name> Continued on next page 2012 © 2012 SAP AG. All rights reserved. 123 Unit 2: Gateway Data Model Generator GW100 You must ensure that: • • • All empty elements are explicitly set to have a null value. See the values highlighted in red above. This requirement applies only to Gateway 2.0 SP3. In SP4 and later, the requirement to specify m:null=“true” will be relaxed. The values of bank_ctry and bank_key should not be altered, as these are the key fields. You change the values of those fields to be updated. l) Then follows the two tags </m:properties> and </atom:content>. These must not be deleted; otherwise the XML would no longer be well formed. m) The tags <atom:id rel="nofollow">, <atom:link rel="nofollow">, <atom:title rel="nofollow"> and <atom:updated rel="nofollow"> can be deleted as they serve no purpose for an UPDATE operation. n) Send the request and look for an HTTP Status Code of “204 No Content” in the “Response Header” section. Figure 171: Status Code: 204 No Content 4. Prepare the CREATE Operation a) Remove the key predicate (highlighted) from the URL used for the UPDATE operation. The key predicate is used to identify and existing entry within a collection. Since we are creating a new bank entry, this part of the URL is no longer necessary z_gw100_rfm_bank_01Collection( bank_key='021800089', bank_ctry='US') b) Change the HTTP Method to POST c) The HTTP Header fields used for the UPDATE operation are also needed for a CREATE operation, so you do not need to touch these values. The X-CSRF-Token will remain valid for as long as the browser session remains open. d) The XML used for the UPDATE operation has the same structure as the XML needed for a CREATE operation. Continued on next page 124 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Generating Data Model for Update Therefore, we will use this XML as our starting point. <?xml version="1.0" encoding="utf-8"?> <atom:entry ... namespace parameters snipped ... rel="nofollow"> <atom:content type="application/xml" rel="nofollow"> <m:properties> <d:street>1060 West Addison St</d:street> <d:bankcountry m:null="true"/> <d:bank_key>021800094</d:bank_key> <d:bank_ctry>US</d:bank_ctry> <d:swift_code>CITIUSXX</d:swift_code> <d:bank_no>021800094</d:bank_no> <d:pobk_curac m:null="true"/> <d:post_bank m:null="true"/> <d:city>Chicago</d:city> <d:bankkey m:null="true"/> <d:region>IL</d:region> <d:bank_branch>Ray's Music Exchange</d:bank_branch> <d:addr_no m:null="true"/> <d:bank_group m:null="true"/> <d:bank_name>Bank of the Blues Brothers</d:bank_name> </m:properties> </atom:content> </atom:entry> At the very least, the only values that need to change are the key values. In the example above, a new bank_key value has been supplied (highlighted in red). e) Send the request and look for an HTTP Status Code of 201 Created. Caution: Remember! If you get an HTTP Status Code of 200 OK, then the create operation was not successful. Figure 172: HTTP Headers The Location field in the HTTP Header gives the URL you can issue to perform a READ operation on the newly created bank. 2012 © 2012 SAP AG. All rights reserved. 125 Unit 2: Gateway Data Model Generator GW100 Lesson Summary You should now be able to: • Extend an existing RFM or BOR based Gateway Service to include update functionality. • Understand the danger posed by Cross-Site Request Forgery attacks and how the SAP NetWeaver Gateway Server prevents them. • Test the new functionality of your Gateway Service from a browser. 126 © 2012 SAP AG. All rights reserved. 2012 GW100 Unit Summary Unit Summary You should now be able to: • Create a read-only Gateway Service based on a Remote Function Module or an Object in the Business Object Repository (BOR). • Expose a Gateway Service for consumption. • Test your Gateway Service from a browser. • Extend an existing RFM or BOR based Gateway Service to include update functionality. • Understand the danger posed by Cross-Site Request Forgery attacks and how the SAP NetWeaver Gateway Server prevents them. • Test the new functionality of your Gateway Service from a browser. 2012 © 2012 SAP AG. All rights reserved. 127 Unit Summary 128 GW100 © 2012 SAP AG. All rights reserved. 2012 Unit 3 Gateway Service Monitoring Unit Overview In this unit, you will learn about the various tools available within an SAP system for monitoring Gateway service activity and errors. Unit Objectives After completing this unit, you will be able to: • Understand the different logging and tracing tools for monitoring SAP NetWeaver Gateway Services. Unit Contents Lesson: Monitoring Gateway ..................................................130 2012 © 2012 SAP AG. All rights reserved. 129 Unit 3: Gateway Service Monitoring GW100 Lesson: Monitoring Gateway Lesson Overview This unit covers the different logging and tracing tools for monitoring SAP NetWeaver Gateway Services. Lesson Objectives After completing this lesson, you will be able to: • Understand the different logging and tracing tools for monitoring SAP NetWeaver Gateway Services. Business Example Alert Monitoring with CCMS Figure 173: Alert Monitoring with CCMS - 1/2 SAP's Computing Center Management System CCMS is SAPs central infrastructure for monitoring system landscapes: All landscape components are continuously checked. As a first and most important check, CCMS ensures the availability of all productive components. Moreover, additional checks safeguard the overall system health. If something is wrong, an alert is triggered, and a person in charge can be notified automatically. Then, CCMS offer a central entry point for deeper analysis: Overview data of the faulty component is presented. Analysis tools guide the administrator directly into helpful expert tools for further analysis. Besides CCMS, SAP NetWeaver automatically generates statistics information, which gives you both as aggregates a good overview, and additionally as single statistics detailed insight what has happened. A convenient and fast way to notify in case of problems the person in charge, can be implemented via SAP Alert Management. 130 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Monitoring Gateway The alert monitor also provides the administration methods that you need to monitor the system. These enable you to set threshold values for alerts and add or adapt auto-reaction and analysis methods. Auto-reaction methods react automatically when an alert is triggered; analysis methods enable you to examine the cause of an alert without leaving the alert monitor. The CCMS Monitoring Infrastructure The CCMS is SAPs central infrastructure for monitoring system landscapes. Keep in mind, however, that it is running in maintenance mode. With SAP Solution Manager 7.1, SAP will introduce the new Monitoring and Alerting Infrastructure (MAI) Figure 174: Alert Monitoring with CCMS - 2/2 SAP's Computing Center Management System CCMS is SAPs central infrastructure for monitoring system landscapes: All landscape components are continuously checked. As a first and most important check, CCMS ensures the availability of all productive components. Moreover, additional checks safeguard the overall system health. If something is wrong, an alert is triggered, and a person in charge can be notified automatically. Then, CCMS offer a central entry point for deeper analysis: Overview data of the faulty component is presented. Analysis tools guide the administrator directly into helpful expert tools for further analysis. Besides CCMS, SAP NetWeaver automatically generates statistics information, which gives you both as aggregates a good overview, and additionally as single statistics detailed insight what has happened. A convenient and fast way to notify in case of problems the person in charge, can be implemented via SAP Alert Management. 2012 © 2012 SAP AG. All rights reserved. 131 Unit 3: Gateway Service Monitoring GW100 The alert monitor also provides the administration methods that you need to monitor the system. These enable you to set threshold values for alerts and add or adapt auto-reaction and analysis methods. Auto-reaction methods react automatically when an alert is triggered; analysis methods enable you to examine the cause of an alert without leaving the alert monitor. The CCMS Monitoring Infrastructure The CCMS is SAPs central infrastructure for monitoring system landscapes. Keep in mind, however, that it is running in maintenance mode. With SAP Solution Manager 7.1, SAP will introduce the new Monitoring and Alerting Infrastructure (MAI) Trace and Log Files Figure 175: Logging and Tracing - Configuration Figure 176: Logging & Tracing - View General Application Log Entries 132 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Monitoring Gateway Figure 177: Logging & Tracing - View Gateway Application Logs Figure 178: Logging & Tracing - View Gateway Error Logs 2012 © 2012 SAP AG. All rights reserved. 133 Unit 3: Gateway Service Monitoring GW100 Figure 179: Internet Communication Manager (ICM) Trace Background RFC Monitoring Figure 180: Background RFC (BGRFC) Monitoring 134 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Monitoring Gateway Lesson Summary You should now be able to: • Understand the different logging and tracing tools for monitoring SAP NetWeaver Gateway Services. 2012 © 2012 SAP AG. All rights reserved. 135 Unit Summary GW100 Unit Summary You should now be able to: • Understand the different logging and tracing tools for monitoring SAP NetWeaver Gateway Services. 136 © 2012 SAP AG. All rights reserved. 2012 Unit 4 OData Channel Model Provider Unit Overview In this unit, you will learn how to create a Gateway Service by means of custom ABAP coding. As with the generated Gateway service you created earlier, you will start by creating a read-only Gateway service. This will then be extend to include update functionality. Unit Objectives After completing this unit, you will be able to: • • • • • • • Understand the architectural elements needed to build a Gateway Service. Understand how to build a basic Gateway Model Provider Class. Understand how to create a basic Data Provider class. Configure a Gateway Service. Test the partial service in a browser. Display the service’s metadata. Understand how to create complex data types for use in OData entity types. Unit Contents Lesson: Developing Model Provider Class ..................................138 Exercise 4: Create A Basic Model Provider Class .....................151 Lesson: Creating Gateway Services .........................................159 Exercise 5: Create Empty Data Provider Class ........................173 Exercise 6: Create a Gateway Service from the Model and Data Provider Classes............................................................175 Exercise 7: Create a Service Catalogue Entry .........................179 Lesson: Creating Complex Types ............................................185 Exercise 8: Create Complex Types and Additional Entity Types.....191 2012 © 2012 SAP AG. All rights reserved. 137 Unit 4: OData Channel Model Provider GW100 Lesson: Developing Model Provider Class Lesson Overview This lesson covers: • • The architectural elements needed to build a Gateway Service How to build a basic Gateway Model Provider Class Lesson Objectives After completing this lesson, you will be able to: • • Understand the architectural elements needed to build a Gateway Service. Understand how to build a basic Gateway Model Provider Class. Business Example Gateway Service Architecture Figure 181: Gateway Service Architecture – 1/5 138 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class Figure 182: Gateway Service Architecture – 2/5 Figure 183: Gateway Service Architecture – 3/5 The configuration screen asks you to enter the internal service name and then uses this value as the external service name. Be careful to enter the name here that you want the end user to see. There is no need to start the internal service name with a Z character. 2012 © 2012 SAP AG. All rights reserved. 139 Unit 4: OData Channel Model Provider GW100 Figure 184: Gateway Service Architecture – 4/5 Figure 185: Gateway Service Architecture – 5/5 The development of a Gateway Service takes place on whichever system has the IW_BEP component installed. The activation of a Gateway service takes place in whichever SAP system has the GW_CORE component installed. It is entirely possible that these may be different systems. 140 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class Entity Data Model Figure 186: Entity Data Model – Overview Figure 187: Entity Data Model – Entity Types Figure 188: Entity Data Model – Properties 2012 © 2012 SAP AG. All rights reserved. 141 Unit 4: OData Channel Model Provider GW100 Figure 189: Entity Data Model – Complex Types Figure 190: Entity Data Model – Associations 1/2 142 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class Figure 191: Entity Data Model – Associations 2/2 Figure 192: Entity Data Model – Navigation Properties 2012 © 2012 SAP AG. All rights reserved. 143 Unit 4: OData Channel Model Provider GW100 Model Provider Class Figure 193: Creating a Basic Model Provider Class – 1/3 Figure 194: Creating a Basic Model Provider Class – 2/3 Figure 195: Creating a Basic Model Provider Class – 3/3 144 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class Figure 196: Implementing the DEFINE Method Entity Type Properties Figure 197: Creating an Entity Type Figure 198: Creating Properties within an Entity Type – 1/2 2012 © 2012 SAP AG. All rights reserved. 145 Unit 4: OData Channel Model Provider GW100 Figure 199: Creating Properties within an Entity Type – 2/2 OData Properties Mapping to Atom Elements Figure 200: Mapping OData Properties to Atom Elements – 1/4 IMPORTANT! Atom terminology is used in the XML, but OData terminology is used in the ABAP coding Atom talks about a Collection containing zero or more Entries, but OData talks about an EntitySet containing zero or more Entities. These terms are synonymous. 146 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class Figure 201: Mapping OData Properties to Atom Elements – 2/4 Figure 202: Mapping OData Properties to Atom Elements – 3/4 The field “Title” is an Atom field and should be included for conformance to the Atom protocol. This field does not have to be used to for an actual title; instead, it can be used to transport various pieces of information from the server to the client E.G. error messages. 2012 © 2012 SAP AG. All rights reserved. 147 Unit 4: OData Channel Model Provider GW100 Figure 203: Mapping OData Properties to Atom Elements – 4/4 OData Properties and ABAP Dictionary Figure 204: Supplying Properties with ABAP Dictionary Metadata – 1/3 148 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class Figure 205: Supplying Properties with ABAP Dictionary Metadata – 2/3 This cryptic error message comes from the fact that when the Gateway Framework tries to initialise your service, the Model Provider class crashes. This leaves the Gateway Framework unable to complete the service initialisation. Figure 206: Supplying Properties with ABAP Dictionary Metadata – 3/3 2012 © 2012 SAP AG. All rights reserved. 149 Unit 4: OData Channel Model Provider GW100 Entity Set Figure 207: Creating an Entity Set Figure 208: Coding a Basic Model Provider Class – Summary 150 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class Exercise 4: Create A Basic Model Provider Class Exercise Objectives After completing this exercise, you will be able to: • Create the metadata needed to define a basic Gateway service. Business Example Before starting to code the model provider class, it is first necessary to understand the data model implemented by the model class. As can be seen from the diagram below, the data model consists of the following parts: 1. 2. Three entity types called Flight, Airport and Booking Two complex data types called Location and GeoCoordinates The Airport entity type is associated both with itself (i.e. other airports) through a navigation path called AirportsTo, and to the Flights entity type through a navigation path called DepartingFlights. The Flight entity type is associated with the Booking entity type through a navigation path called Bookings This data model will now be implemented as a Gateway Model Provider class in ABAP. The navigation paths described by the entity type associations will be implemented in the Gateway Data Provider class. 2012 © 2012 SAP AG. All rights reserved. 151 Unit 4: OData Channel Model Provider GW100 Task: Figure 209: Navigation Paths 152 1. Create a Data Model Class 2. Create Local Data Types 3. Redefine Method DEFINE © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class Solution 4: Create A Basic Model Provider Class Task: Figure 210: Navigation Paths 1. Create a Data Model Class a) Run transaction SE80 (ABAP Development Workbench) b) Select “Class / Interface” from the drop-down list. c) Give your new ABAP class the name ZCL_GW100_MP_nn (where nn is your group number) and press enter. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 153 Unit 4: OData Channel Model Provider GW100 Figure 211: Object Type d) After confirming that you want to create a new class, ensure that the Object Type is set to “Object” and press enter. e) On the following pop-up screen enter a description for the new ABAP class and press enter. Make sure that the “Class Type” remains set to “Usual ABAP Class”. Figure 212: Usual ABAP Class f) When asked for the package name press “Local Object” or enter ZGW100_nn (where nn is your group number) and press enter. g) Once the object has been created, double click on the new object name. This will cause the object’s methods to be displayed (there are none at the moment). h) Switch into change mode and select the Properties tab. i) Click on the superclass button, enter /IWBEP/CL_MGW_ABS_MODEL as the name of the superclass and press Save (or Ctrl-S). Continued on next page 154 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class 2. Create Local Data Types a) Before we can implement any methods, we must first define some data types within this class. In this case, we will use the fields found within the data dictionary structure SPFLI to supply metadata for the OData interface properties. Here, we will start with the data type to represent a Booking because this contains no complex types. b) c) d) Select the “Types” tab and enter the following: Type: BOOKING_S Visibility: Public Description: Booking structure Click on the type definition button Replace the line types booking_s. with the following code: types: begin of booking_s, airlineid type spfli-carrid, connectionno type spfli-connid, flightdate type sflight-fldate, bookingid type sbook-bookid, customerno type sbook-customid, customername type sbook-passname, price type sflight-price, currencycode type sflight-currency, bookingdate type sbook-order_date, title type string, end of booking_s. types: bookings_t type standard table of booking_s. We have now defined local data types to describe a single booking (booking_s) and a table of such bookings (booking_t). e) 3. Save your changes. Redefine Method DEFINE a) Right click on the DEFINE method and select Redefine from the context menu. b) Copy and paste the following code: Continued on next page 2012 © 2012 SAP AG. All rights reserved. 155 Unit 4: OData Channel Model Provider GW100 method DEFINE. data: lo_entity_type type ref to /iwbep/if_mgw_odata_entity_typ, lo_property type ref to /iwbep/if_mgw_odata_property. ****************************************************************** * ENTITIES ****************************************************************** "Define Entity Booking lo_entity_type = model->create_entity_type( 'Booking' ). "Define property AirlineId and set it as a key lo_property = lo_entity_type->create_property( iv_property_name = 'AirlineId' iv_abap_fieldname = 'AIRLINEID' ). lo_property->set_is_key( ). "Define property ConnectionNo and set it as a key lo_property = lo_entity_type->create_property( iv_property_name = 'ConnectionNo' iv_abap_fieldname = 'CONNECTIONNO' ). lo_property->set_is_key( ). "Define property FlightDate and set it as a key lo_property = lo_entity_type->create_property( iv_property_name = 'FlightDate' iv_abap_fieldname = 'FLIGHTDATE' ). lo_property->set_is_key( ). "Define property BookingId and set it as a key lo_property = lo_entity_type->create_property( iv_property_name = 'BookingId' iv_abap_fieldname = 'BOOKINGID' ). lo_property->set_is_key( ). lo_property = lo_entity_type->create_property( iv_property_name = 'CustomerNo' iv_abap_fieldname = 'CUSTOMERNO' ). "Define property CustomerName lo_property = lo_entity_type->create_property( iv_property_name = 'CustomerName' iv_abap_fieldname = 'CUSTOMERNAME' ). "The set_as_author() method assigns the current property to the "ATOM author field. The Boolean parameter defines whether the "property is visible in the content lo_property->set_as_author( iv_keep_in_content = abap_true ). lo_property = lo_entity_type->create_property( iv_property_name = 'Price' iv_abap_fieldname = 'PRICE' ). lo_property = lo_entity_type->create_property( iv_property_name = 'CurrencyCode' Continued on next page 156 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Model Provider Class iv_abap_fieldname = 'CURRENCYCODE' ). lo_property = lo_entity_type->create_property( iv_property_name = 'BookingDate' iv_abap_fieldname = 'BOOKINGDATE' ). "Define property Title. Assign it to the ATOM field "Title", "but do not keep it in the content lo_property = lo_entity_type->create_property( iv_property_name = 'Title' iv_abap_fieldname = 'TITLE' ). lo_property->set_as_title( iv_keep_in_content = abap_false ). "Use our previously defined data type to supply the metadata "for the properties in the OData interface. Fields are matched "by name. lo_entity_type->bind_structure( 'Z_CL_GW100_MP_nn=>BOOKING_S' ). "Name the EntitySet Bookings. Omitting this statement will "cause an entity set to be created automatically and called "BookingCollection lo_entity_type->create_entity_set( 'Bookings' ). endmethod. Caution: Do not forget to correct the class reference in the bind_structure() method call! In the area highlighted in yellow, change the nn in ZCL_GW100_MP_nn to your group number. c) Save and activate class ZCL_GW100_MP_nn. At this point in time, we cannot invoke this model provider class because we have not yet created an associated data provider class. This will be done in the next exercise. 2012 © 2012 SAP AG. All rights reserved. 157 Unit 4: OData Channel Model Provider GW100 Lesson Summary You should now be able to: • Understand the architectural elements needed to build a Gateway Service. • Understand how to build a basic Gateway Model Provider Class. 158 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Lesson: Creating Gateway Services Lesson Overview This lesson covers: • • • • How to create a basic Data Provider class Configure a Gateway Service Test the partial service in a browser Display the service’s metadata Lesson Objectives After completing this lesson, you will be able to: • • • • Understand how to create a basic Data Provider class. Configure a Gateway Service. Test the partial service in a browser. Display the service’s metadata. Business Example Gateway Service and Data Provider Figure 213: Testing the Gateway Service's Model Provider Class 2012 © 2012 SAP AG. All rights reserved. 159 Unit 4: OData Channel Model Provider GW100 Figure 214: Create an Empty Data Provider Class - 1/2 Figure 215: Create an Empty Data Provider Class - 2/2 160 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Configuration Wrapper for the Data Provider Figure 216: Gateway Service Architecture - Reminder 1/2 Figure 217: Gateway Service Architecture - Reminder 2/2 2012 © 2012 SAP AG. All rights reserved. 161 Unit 4: OData Channel Model Provider GW100 Figure 218: Configuration Wrapper for the Metadata Provider - 1/3 Figure 219: Configuration Wrapper for the Metadata Provider - 2/3 162 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Figure 220: Configuration Wrapper for the Metadata Provider - 3/3 Figure 221: Configuration Wrapper for the Data Provider - 1/5 Figure 222: Configuration Wrapper for the Data Provider - 2/5 2012 © 2012 SAP AG. All rights reserved. 163 Unit 4: OData Channel Model Provider GW100 Figure 223: Configuration Wrapper for the Data Provider - 3/5 Figure 224: Configuration Wrapper for the Data Provider - 4/5 Figure 225: Configuration Wrapper for the Data Provider - 5/5 164 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Gateway Service Catalogue Figure 226: Gateway Service Catalogue - Summary Component IW_SCS is only needed if you create Gateway Services that use screen scraping. It is entirely possible for all the Gateway Add-On Components to be installed in a single server; however, this installation arrangement is only recommended for test and development scenarios. For all productive scenarios, it is recommended that a separate Gateway Hub server is installed. Figure 227: Create an Entry in the Gateway Service Catalogue - 1/4 2012 © 2012 SAP AG. All rights reserved. 165 Unit 4: OData Channel Model Provider GW100 Figure 228: Create an Entry in the Gateway Service Catalogue - 2/4 Figure 229: Create an Entry in the Gateway Service Catalogue - 3/4 166 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Figure 230: Create an Entry in the Gateway Service Catalogue - 4/4 Gateway Service Document Figure 231: Display the Service Document The query string parameter sap-client is not necessary as long as the Gateway Service runs in the backend system's default client. The query string parameter $format=xml is necessary when testing a Gateway Service from a browser. This parameter tells the Gateway server to return the HTTP response using the MIME type application/xml. Depending on your browser, various degrees of formatting will be performed on the XML text response before it is displayed. 2012 © 2012 SAP AG. All rights reserved. 167 Unit 4: OData Channel Model Provider GW100 If the $format=xml parameter is omitted, then the Gateway server will return the response using the MIME type application/atomsvc+xml. The browser will then interpret this as an Atom feed and will format the response accordingly. Figure 232: Identify the Gateway Service's Base URL Figure 233: Identify the Collections Provided by the Gateway Service 168 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Figure 234: Display a Gateway Service's Metadata - 1/2 Figure 235: Display a Gateway Service's Metadata - 2/2 2012 © 2012 SAP AG. All rights reserved. 169 Unit 4: OData Channel Model Provider GW100 Figure 236: Correspondence of ABAP Coding with OData XML - 1/8 Figure 237: Correspondence of ABAP Coding with OData XML - 2/8 Figure 238: Correspondence of ABAP Coding with OData XML - 3/8 170 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Figure 239: Correspondence of ABAP Coding with OData XML - 4/8 Figure 240: Correspondence of ABAP Coding with OData XML - 5/8 Figure 241: Correspondence of ABAP Coding with OData XML - 6/8 2012 © 2012 SAP AG. All rights reserved. 171 Unit 4: OData Channel Model Provider GW100 Figure 242: Correspondence of ABAP Coding with OData XML - 7/8 Figure 243: Correspondence of ABAP Coding with OData XML - 8/8 172 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Exercise 5: Create Empty Data Provider Class Exercise Objectives After completing this exercise, you will be able to: • Create an empty Gateway data provider class and perform the configuration necessary to execute the basic Gateway service. At this point in time, the Gateway service does not yet contain any business functionality, but is able to displays the structure of its interface. Business Example Task: 1. Create an Empty Data Provider Class The coding developed so far should now be tested. In order to do this, we must configure the Gateway system to recognize that this Model Provider class belongs to a Gateway service. However, a Gateway Service is composed from at least two classes – a Model Provider class and one or more Data Provider classes. The next step therefore is to create a Data Provider class. 2012 © 2012 SAP AG. All rights reserved. 173 Unit 4: OData Channel Model Provider GW100 Solution 5: Create Empty Data Provider Class Task: 1. Create an Empty Data Provider Class The coding developed so far should now be tested. In order to do this, we must configure the Gateway system to recognize that this Model Provider class belongs to a Gateway service. However, a Gateway Service is composed from at least two classes – a Model Provider class and one or more Data Provider classes. The next step therefore is to create a Data Provider class. a) Create another ABAP class called ZCL_GW100_DP_nn where nn is your group number. b) As with class ZCL_GW100_MP_nn, the object type is “Class”, it should be given a meaningful description. c) The Data provider class must have class /IWBEP/CL_MGW_ABS_DATA as it’s superclass. d) Save your changes and activate class. At the moment, the data provider class is nothing more than an empty shell; however, it implements the standard interface required by all Gateway Data Provider classes. Therefore, it contains sufficient functionality to allow you to see the results of your ABAP coding in the model provider class. 174 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Exercise 6: Create a Gateway Service from the Model and Data Provider Classes Exercise Objectives After completing this exercise, you will be able to: • Create an empty Gateway data provider class and perform the configuration necessary to execute the basic Gateway service. At this point in time, the Gateway service does not yet contain any business functionality, but is able to displays the structure of its interface. Business Example Remember that at the ABAP coding level, the Model and Data Provider classes are not required to have any direct reference to each other. The association between these two classes is established using configuration, not coding. The configuration that now needs to be performed will associate your Model Provider class (ZCL_GW100_MP_nn) with the Data Provider class (ZCL_GW100_DP_nn). The configuration process creates two wrapper objects that are then associated with each other. Configuration Summary 1. 2. 3. 4. The Model Provider class is wrapped in a Technical Model. The Runtime Data Provider class is wrapped in a Service Group. The Technical Model is then assigned to the Service Group. Create an entry in the Service Catalogue. The first three configuration steps take place in the ABAP system containing the Gateway add-on component IW_BEP. The last configuration step takes place in the ABAP system containing the Gateway add-on component GW_CORE. As is the case with the SAP training environment, it is entirely possible that these two components are installed in the same ABAP system. Task: 2012 1. Configure a Technical Model 2. Configure a Service Group © 2012 SAP AG. All rights reserved. 175 Unit 4: OData Channel Model Provider GW100 Solution 6: Create a Gateway Service from the Model and Data Provider Classes Task: 1. Configure a Technical Model a) Start transaction SPRO and enter the SAP Reference IMG. b) Follow the path SAP NetWeaver → Gateway Business Suite Enablement → Backend OData Channel → Service Development for Backend OData Channel Figure 244: Service Development for Backend OData Channel c) Start the “Maintain Models” transaction. d) Enter the Technical Model Name of ZGW100_TM_nn and a version number of 1. e) Press “Create New Model”. f) On the following screen, enter the name of the model provider class being wrapped and give it some meaningful description. Continued on next page 176 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Figure 245: Model Provider Class – Description In this case, the model provider class is ZCL_GW100_MP_nn. Press save. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 177 Unit 4: OData Channel Model Provider 2. GW100 Configure a Service Group a) Return to the IMG hierarchy and run the “Maintain Service” transaction. This is where a Service Group is used to wrap the Data Provider class. Caution: Whatever name you enter as the Technical Service Name becomes the name that will appear in the URL that runs this service (i.e. the External Service Name). Therefore, you must choose a name that will be meaningful to the end user. Enter Flight_Information_nn as the Technical Service Name and a version number of 1. Press the create button. b) On the next screen, enter the Data Provider class name ZCL_GW100_DP_nn and a meaningful description. Figure 246: Data Provider Class – Description You must now save your changes otherwise you cannot assign a technical model. c) Once you have saved the service information, press the “Assign Model” button. d) Enter the name of your Technical Model Z_GW100_TM_nn and press the save icon to close the pop-up window. e) Press save on the toolbar to save the assignment. Your Model and Data Provider classes are now associated with each other and form an executable Gateway Service. 178 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Exercise 7: Create a Service Catalogue Entry Exercise Objectives After completing this exercise, you will be able to: • Create an empty Gateway data provider class and perform the configuration necessary to execute the basic Gateway service. At this point in time, the Gateway service does not yet contain any business functionality, but is able to displays the structure of its interface. Business Example Now that the Gateway Service is functional, it needs to be made visible to the outside world. To do this, it is necessary to create an entry in the Service Catalogue. Remember how the following installation scenarios alter the location of these configuration steps: • • ABAP development of custom Gateway Services takes place in whichever system contains the Gateway add-on component IW_BEP. External users consume Gateway Services by connecting to whichever SAP system contains the Gateway add-on component GW_CORE. This is the system in which the Service Catalogue entry must be made. In the case of the SAP training environment, IW_BEP and GW_CORE have been installed in the same system. Therefore, there is no need to log on to a different system in order to perform the following configuration. However, when you return to your own system environment, it is entirely possible that IW_BEP and GW_CORE could be installed on separate systems. If that is the case, then you must log on to the system in which GW_CORE has been installed before performing these instructions. Task: 1. 2012 Create a Service Catalogue Entry and Test the Service © 2012 SAP AG. All rights reserved. 179 Unit 4: OData Channel Model Provider GW100 Solution 7: Create a Service Catalogue Entry Task: 1. Create a Service Catalogue Entry and Test the Service a) Run transaction /IWFND/MAINT_SERVICE in the system containing the Gateway add-on component GW_CORE. Figure 247: Component GW_CORE This transaction shows all the Services currently available from this Gateway Server. At the moment, your Flight_Information_nn service is missing. b) Click on the “Add Service” button in the tool bar. c) Enter the name of the system alias containing your Gateway service. Since the SAP training system has been set up with GW_CORE and IW_BEP in the same system, the System Alias is LOCAL. Figure 248: Filter The Technical Service Name is Flight_Information_nn. Press enter and the details of your service are now displayed. Continued on next page 180 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services Figure 249: Add Service d) Enter your package name and press “Add Service”. Figure 250: Add Service You should see a success message in the status bar at the bottom of the screen. Figure 251: Service Catalog e) Press “Back” in the tool bar or F3. Your service now exists in the Service Catalogue and can now be tested from a browser. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 181 Unit 4: OData Channel Model Provider GW100 f) The easiest way to locate your service in the catalogue is to click on the column header for “External Service Name” and then press the sort button to sort the table rows into ascending alphabetical order . g) Select the row containing your service FLIGHT_INFORMATION_nn then press the “Call Browser” button. Figure 252: FLIGHT_INFORMATION_nn h) After confirming your logon credentials, you will see the Service Document for this Gateway Service. Figure 253: Service Document At the moment, this service contains no functionality; however, we can see our service contains a collection called “Bookings”. It is also possible to look at the metadata that describes the Bookings collection. Continued on next page 182 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Gateway Services i) In the browser address line, remove the query string parameter ?$format=xml and replace it with $metadata. Note: IMPORTANT! $metadata is an OData command, not a query string parameter; therefore, you must delete the question mark character that denotes the start of the query string. j) You will now see the metadata describing the Booking collection. Figure 254: Metadata Describing Notice that the XML element <EntityType Name=“Booking”> and everything it contains, has been generated as a direct result of the ABAP coding in the DEFINE method of your Model Provider class. This is as much testing as can be done with the Gateway Service in its current state; however, this is enough to see the connection between the ABAP coding in the Model Provider’s DEFINE method and the <Property> elements. 2012 © 2012 SAP AG. All rights reserved. 183 Unit 4: OData Channel Model Provider GW100 Lesson Summary You should now be able to: • Understand how to create a basic Data Provider class. • Configure a Gateway Service. • Test the partial service in a browser. • Display the service’s metadata. 184 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Complex Types Lesson: Creating Complex Types Lesson Overview This lesson covers how to create complex data types for use in OData entity types. Lesson Objectives After completing this lesson, you will be able to: • Understand how to create complex data types for use in OData entity types. Business Example Complex Types Figure 255: Creating a Complex Type - 1/6 Figure 256: Creating a Complex Type - 2/6 2012 © 2012 SAP AG. All rights reserved. 185 Unit 4: OData Channel Model Provider GW100 Figure 257: Creating a Complex Type - 3/6 Figure 258: Creating a Complex Type - 4/6 Figure 259: Creating a Complex Type - 5/6 186 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Complex Types Figure 260: Creating a Complex Type - 6/6 Figure 261: Test the Complex Type Modelling Tools Figure 262: Entity Data Model - Modelling Tools 1/3 2012 © 2012 SAP AG. All rights reserved. 187 Unit 4: OData Channel Model Provider GW100 Figure 263: Entity Data Model - Modelling Tools 2/3 Figure 264: Entity Data Model - Modelling Tools 3/3 188 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Complex Types Gateway Service URL Figure 265: Gateway Service Base URL Figure 266: Case Sensitivity of URL Values 2012 © 2012 SAP AG. All rights reserved. 189 Unit 4: OData Channel Model Provider 190 © 2012 SAP AG. All rights reserved. GW100 2012 GW100 Lesson: Creating Complex Types Exercise 8: Create Complex Types and Additional Entity Types Exercise Objectives After completing this exercise, you will be able to: • Create the remaining entity types needed for the Flight Information Gateway service. Business Example Task: 1. Create Complex Types 2. Define the Remaining Entity Types Several more entity types need to be defined. Specifically, these are the Airport and Flight entity types. As with the other entity types we have created, we will reference built-in data types within our model provider class Z_CL_GW100_MP_nn that in turn, derive their metadata from the ABAP dictionary. 2012 © 2012 SAP AG. All rights reserved. 191 Unit 4: OData Channel Model Provider GW100 Solution 8: Create Complex Types and Additional Entity Types Task: 1. Create Complex Types a) Run transaction SE80. b) Edit your Model Provider class ZCL_GW100_MP_nn. c) Double click on the class name to display the class overview. d) Ensure that you are in change mode and select the Types tab. e) Enter the name geocoordinates_s, set the visibility to Public and press the type definition button . f) Replace the statement types geocoordinates_s. with the following type definitions. types: begin of geocoordinates_s, longitude type sgeocity-longitude, latitude type sgeocity-latitude, end of geocoordinates_s. types: begin of location_s, country type string, city type string, airport type string, time type spfli-deptime, end of location_s . Since the complex types GeoCoordinates and Location will never be entity sets in their own right, there is no need to define tables based on these types. g) h) Go back to the redefinition of method DEFINE and double click to edit it. Add an extra declaration for the local object lo_complex_type: method DEFINE. data: lo_entity_type type ref to /iwbep/if_mgw_odata_entity_typ, lo_property type ref to /iwbep/if_mgw_odata_property, lo_complex_type type ref to /iwbep/if_mgw_odata_cmplx_type. Continued on next page 192 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Complex Types i) Then add the following code immediately after the variable declaration section, remembering to change the class reference highlighted in yellow to your own Model Provider class. *************************************************************** * COMPLEX TYPES *************************************************************** "Complex type for Location lo_complex_type = model->create_complex_type( 'Location' ). lo_complex_type->create_property( iv_property_name = 'Country' iv_abap_fieldname = 'COUNTRY' ). lo_complex_type->create_property( iv_property_name = 'City' iv_abap_fieldname = 'CITY' ). lo_complex_type->create_property( iv_property_name = 'Airport' iv_abap_fieldname = 'AIRPORT' ). lo_complex_type->create_property( iv_property_name = 'Time' iv_abap_fieldname = 'TIME' ). lo_complex_type->bind_structure( 'Z_CL_GW100_MP_nn=>LOCATION_S' ). "Complex type for GeoCoordinates lo_complex_type = model->create_complex_type( 'GeoCoordinates' ). lo_complex_type->create_property( iv_property_name = 'Longitude' iv_abap_fieldname = 'LONGITUDE' ). lo_complex_type->create_property( iv_property_name = 'Latitude' iv_abap_fieldname = 'LATITUDE' ). lo_complex_type->bind_structure( 'Z_CL_GW100_MP_nn=>GEOCOORDINATES_S' ). Hint: Do not forget to correct the class reference in the bind_structure() method calls to point to your model provider class! j) Save and activate your changes. k) Go back to your browser and re-issue the $metadata URL. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 193 Unit 4: OData Channel Model Provider l) GW100 You can now see that although the complex types for GeoCoordinates and Location have not yet been assigned to an entity, they exist in the metadata definition. (The XML has been formatted for clarity.) <ComplexType Name="Location"> <Property Name="Country" Type="Edm.String" Nullable="true" /> <Property Name="City" Type="Edm.String" Nullable="true" /> <Property Name="Airport" Type="Edm.String" Nullable="true" /> <Property Name="Time" Type="Edm.Time" Nullable="true" sap:label="Departure" /> </ComplexType> <ComplexType Name="GeoCoordinates"> <Property Name="Longitude" Type="Edm.Double" sap:label="Longitude" Nullable="true" /> <Property Name="Latitude" Type="Edm.Double" sap:label="Latitude" Nullable="true" /> </ComplexType> 2. Define the Remaining Entity Types Several more entity types need to be defined. Specifically, these are the Airport and Flight entity types. As with the other entity types we have created, we will reference built-in data types within our model provider class Z_CL_GW100_MP_nn that in turn, derive their metadata from the ABAP dictionary. a) Go back to the Types tab and enter the name FLIGHT_S of visibility “Public” and press the type definition button. b) Replace the statement types flight_s. with the following type definitions types: begin of flight_s, airlineid type spfli-carrid, connectionno type spfli-connid, flightdate type sflight-fldate, price type sflight-price, currencycode type sflight-currency, distance type spfli-distance, distanceunit type spfli-distid, flighttime type spfli-fltime, planetype type sflight-planetype, departure type location_s, arrival type location_s, title type string, end of flight_s. types: flights_t type standard table of flight_s. Continued on next page 194 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Complex Types types: begin of airport_s, iatacode type char3, name type char20, geocoordinates type geocoordinates_s, url type string, title type string, end of airport_s. types: airports_t type standard table of airport_s. c) Save these changes. d) After the coding to create the Booking entity, add the following code, remembering to edit the class names highlighted in yellow: ****************************************************************** "Define Entity Airport lo_entity_type = model->create_entity_type( 'Airport' ). lo_property = lo_entity_type->create_property( iv_property_name = 'IATACode' iv_abap_fieldname = 'IATACODE' ). lo_property->set_is_key( ). lo_property = lo_entity_type->create_property( iv_property_name = 'Name' iv_abap_fieldname = 'NAME' ). lo_entity_type->create_complex_property( iv_property_name = 'GeoCoordinates' iv_complex_type_name = 'GeoCoordinates' ). lo_property = lo_entity_type->create_property( iv_property_name = 'URL' iv_abap_fieldname = 'URL' ). "Set property title as atom title and do not keep the property "in the content lo_property = lo_entity_type->create_property( iv_property_name = 'Title' iv_abap_fieldname = 'TITLE' ). lo_property->set_as_title( iv_keep_in_content = abap_false ). lo_entity_type->bind_structure( 'Z_CL_GW100_MP_nn=>AIRPORT_S' ). "Name the EntitySet Airports instead of the default "AirportCollection lo_entity_type->create_entity_set( 'Airports' ). ******************************************************************** "Define Entity Flight lo_entity_type = model->create_entity_type( 'Flight' ). Continued on next page 2012 © 2012 SAP AG. All rights reserved. 195 Unit 4: OData Channel Model Provider GW100 lo_property = lo_entity_type->create_property( iv_property_name = 'AirlineId' iv_abap_fieldname = 'AIRLINEID' ). lo_property->set_is_key( ). lo_property = lo_entity_type->create_property( iv_property_name = 'ConnectionNo' iv_abap_fieldname = 'CONNECTIONNO' ). lo_property->set_is_key( ). lo_property = lo_entity_type->create_property( iv_property_name = 'FlightDate' iv_abap_fieldname = 'FLIGHTDATE' ). lo_property->set_is_key( ). lo_property = lo_entity_type->create_property( iv_property_name = 'Price' iv_abap_fieldname = 'PRICE' ). lo_property = lo_entity_type->create_property( iv_property_name = 'CurrencyCode' iv_abap_fieldname = 'CURRENCYCODE' ). lo_property = lo_entity_type->create_property( iv_property_name = 'Distance' iv_abap_fieldname = 'DISTANCE' ). lo_property = lo_entity_type->create_property( iv_property_name = 'DistanceUnit' iv_abap_fieldname = 'DISTANCEUNIT' ). lo_property = lo_entity_type->create_property( iv_property_name = 'FlightTime' iv_abap_fieldname = 'FLIGHTTIME' ). lo_property = lo_entity_type->create_property( iv_property_name = 'PlaneType' iv_abap_fieldname = 'PLANETYPE' ). lo_entity_type->create_complex_property( iv_property_name = 'Departure' iv_complex_type_name = 'Location' ). lo_entity_type->create_complex_property( iv_property_name = 'Arrival' iv_complex_type_name = 'Location' ). "Set property title as atom title and do not keep the property "in the content lo_property = lo_entity_type->create_property( iv_property_name = 'Title' iv_abap_fieldname = 'TITLE' ). lo_property->set_as_title( iv_keep_in_content = abap_false ). lo_entity_type->bind_structure('Z_CL_GW100_MP_nn=>FLIGHT_S' ). "Name the EntitySet Flights instead of the default "FlightCollection Continued on next page 196 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Creating Complex Types lo_entity_type->create_entity_set( 'Flights' ). 2012 e) Save and activate your changes. f) Go back to the browser and re-issue the $metadata URL. g) You will now see that there are two extra <EntityType> elements – one for Flight and one for Airport. © 2012 SAP AG. All rights reserved. 197 Unit 4: OData Channel Model Provider GW100 Lesson Summary You should now be able to: • Understand how to create complex data types for use in OData entity types. 198 © 2012 SAP AG. All rights reserved. 2012 GW100 Unit Summary Unit Summary You should now be able to: • Understand the architectural elements needed to build a Gateway Service. • Understand how to build a basic Gateway Model Provider Class. • Understand how to create a basic Data Provider class. • Configure a Gateway Service. • Test the partial service in a browser. • Display the service’s metadata. • Understand how to create complex data types for use in OData entity types. 2012 © 2012 SAP AG. All rights reserved. 199 Unit Summary 200 GW100 © 2012 SAP AG. All rights reserved. 2012 Unit 5 OData Channel Data Provider Unit Overview In this unit, you will learn how to implement the business functionality of a Gateway service in an ABAP class known as the Data Provider class. Unit Objectives After completing this unit, you will be able to: • • • • • • • Understand architectural principles. Understand the Relationship between HTTP Requests, OData Operations and Methods in the Data Provider Class. Understand how to implement the QUERY and READ operations. Understand how to implement the CREATE operation within a Gateway Data Provider Class. Understand how to implement a custom OData action. Understand how Entity Types in a Data Model are Related Using Associations. Understand how Associations are Implemented at Runtime Using Navigation Paths. Unit Contents Lesson: Developing Data Provider Class for Read ........................202 Exercise 9: Implement the QUERY Operation .........................207 Exercise 10: Implement the READ Operation ..........................221 Lesson: Developing Data Provider Class for Update ......................233 Exercise 11: Implement the CREATE Operation .......................239 Exercise 12: Implement CancelBooking Custom Action ..............255 Lesson: Using Associations and Navigation Paths.........................263 Exercise 13: Create Associations and Navigation Properties ........269 2012 © 2012 SAP AG. All rights reserved. 201 Unit 5: OData Channel Data Provider GW100 Lesson: Developing Data Provider Class for Read Lesson Overview This lesson covers the following development aspects of a Gateway Data Provider Class • • • Architectural principles The Relationship between HTTP Requests, OData Operations and Methods in the Data Provider Class How to implement the QUERY and READ operations Lesson Objectives After completing this lesson, you will be able to: • • • Understand architectural principles. Understand the Relationship between HTTP Requests, OData Operations and Methods in the Data Provider Class. Understand how to implement the QUERY and READ operations. Business Example Data Provider Class Figure 267: Gateway Service Architecture The development of a Gateway Service takes place on whichever system has the IW_BEP component installed. 202 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read The activation of a Gateway service takes place in whichever SAP system has the GW_CORE component installed. It is entirely possible that these may be different systems. Figure 268: Gateway Data Provider Class - General Architecture The development of a Gateway Service takes place on whichever system has the IW_BEP component installed. The activation of a Gateway service takes place in whichever SAP system has the GW_CORE component installed. It is entirely possible that these may be different systems. Figure 269: One Data Provider Class per Entity Type 2012 © 2012 SAP AG. All rights reserved. 203 Unit 5: OData Channel Data Provider GW100 Figure 270: HTTP Request - OData Operation - ABAP Method QUERY and READ Operations Figure 271: QUERY and READ Operations in Top Level Data Provider 204 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read Figure 272: GET_ENTITYSET Method in Top Level Data Provider Class Figure 273: Implement GET_ENTITYSET in Each Data Provider Class 2012 © 2012 SAP AG. All rights reserved. 205 Unit 5: OData Channel Data Provider GW100 Figure 274: GET_ENTITY Method in Top Level Data Provider Class Figure 275: Implement GET_ENTITY in Each Data Provider Class 206 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read Exercise 9: Implement the QUERY Operation Exercise Objectives After completing this exercise, you will be able to: • Create a Gateway service providing customized flight information Business Example You wish to provide a Gateway service that displays flight information. In a Gateway Data Provider class, the QUERY operation is implemented by the GET_ENTITYSET method and the READ operation is implemented by the GET_ENTITY method. In our case, we have a total of four Data Provider class; one top level Data Provider, and three subordinate Data Provider classes for each of the entity types in our data model. Therefore, we must implement the GET_ENTITYSET and GET_ENTITY methods in all four classes. So far, we have already created a top level Data Provider class, but it contains no functionality. Also, none of the subordinate data provider classes exist yet. 2012 © 2012 SAP AG. All rights reserved. 207 Unit 5: OData Channel Data Provider GW100 Task: Figure 276: Gateway Data Provider 208 1. Create Subordinate Data Provider Classes 2. Implement Method GET_ENTITYSET in the Top Level Data Provider Class 3. Implement Method GET_ENTITYSET in the Airport Data Provider Class 4. Implement Method GET_ENTITYSET in the Flight Data Provider Class 5. Implement Method GET_ENTITYSET in the Booking Data Provider Class 6. Test the QUERY Operations From A Browser © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read Solution 9: Implement the QUERY Operation Task: Figure 277: Gateway Data Provider 1. Create Subordinate Data Provider Classes a) Log on to the Gateway Service development system. b) Run transaction SE80. c) Create three new ABAP classes: one for each entity type in the data model. The ABAP classes are named: ZCL_GW100_DP_AIRPORT_nn ZCL_GW100_DP_FLIGHT_nn ZCL_GW100_DP_BOOKING_nn Where nn is your group number. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 209 Unit 5: OData Channel Data Provider GW100 Figure 278: Create Class Figure 279: Class Interface Each class must implement the interface /IWBEP/IF_MGW_APPL_SRV_RUNTIME. For each new class, save and activate your changes. 2. Implement Method GET_ENTITYSET in the Top Level Data Provider Class a) Edit your top level Data Provider class ZCL_GW100_DP_nn. b) Expand Methods → Inherited Methods → /IWBEP/IF_MGW_APPL_SRV_RUNTIME c) Right click on method GET_ENTITYSET and select Redefine from the context menu. d) Replace the contents of method GET_ENTITYSET with the following code. Be careful to replace the class names highlighted in yellow with the correct name of your Data or Model Provider class. Continued on next page 210 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read METHOD /iwbep/if_mgw_appl_srv_runtime~get_entityset. data: * Reference the specific data provider class for each entity set lo_airport type ref to zcl_gw100_dp_airport_nn, lo_flight type ref to zcl_gw100_dp_flight_nn, lo_booking type ref to zcl_gw100_dp_booking_nn. * What entity set has been requested? * Be careful! The entity set names are case-sensitive! case iv_entity_set_name. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * AIRPORTS * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * when 'Airports'. create: object lo_airport, data er_entityset type zcl_gw100_mp_nn=>airports_t. lo_airport->/iwbep/if_mgw_appl_srv_runtime~get_entityset( exporting iv_entity_name = iv_entity_name iv_source_name = iv_source_name iv_entity_set_name = iv_entity_set_name it_filter_select_options = it_filter_select_options it_order = it_order is_paging = is_paging it_navigation_path = it_navigation_path it_key_tab = it_key_tab iv_filter_string = iv_filter_string iv_search_string importing er_entityset = iv_search_string = er_entityset ). * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * FLIGHTS * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * when 'Flights'. create: object lo_flight, data er_entityset type zcl_gw100_mp_nn=>flights_t. lo_flight->/iwbep/if_mgw_appl_srv_runtime~get_entityset( exporting iv_entity_name = iv_entity_name iv_source_name = iv_source_name iv_entity_set_name = iv_entity_set_name it_filter_select_options = it_filter_select_options it_order = it_order is_paging = is_paging it_navigation_path = it_navigation_path it_key_tab = it_key_tab iv_filter_string = iv_filter_string Continued on next page 2012 © 2012 SAP AG. All rights reserved. 211 Unit 5: OData Channel Data Provider GW100 iv_search_string importing er_entityset = iv_search_string = er_entityset ). * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * BOOKINGS * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * when 'Bookings'. create: object lo_booking, data er_entityset type zcl_gw100_mp_nn=>bookings_t. lo_booking->/iwbep/if_mgw_appl_srv_runtime~get_entityset( exporting iv_entity_name = iv_entity_name iv_source_name = iv_source_name iv_entity_set_name = iv_entity_set_name it_filter_select_options = it_filter_select_options it_order = it_order is_paging = is_paging it_navigation_path = it_navigation_path it_key_tab = it_key_tab iv_filter_string = iv_filter_string iv_search_string importing er_entityset = iv_search_string = er_entityset ). * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Something else... * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * when others. " Add handler here endcase. endmethod. e) 3. Save and activate your changes. Implement Method GET_ENTITYSET in the Airport Data Provider Class a) Edit your Airport Data Provider class ZCL_GW100_DP_AIRPORT_nn. b) Expand the branch Methods → /IWBEP/IF_MGW_APPL_SRV_RUNTIME Continued on next page 212 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read Figure 280: Methods c) Right click on GET_ENTITYSET and from the context menu, select Change → Implementation. Figure 281: Change → Implementation d) Replace the entire method with the following code, remembering to update the class names highlighted in yellow: method /iwbep/if_mgw_appl_srv_runtime~get_entityset. data: " Structure for one airport ls_airport type zcl_gw100_mp_nn=>airport_s, " Table of airports lt_airports type standard table of spfli, " Single values needed in output structure Continued on next page 2012 © 2012 SAP AG. All rights reserved. 213 Unit 5: OData Channel Data Provider GW100 lv_airport type spfli-airpfrom, lv_country type spfli-countryfr. field-symbols: <airport rel="nofollow"> type spfli, <key> type /iwbep/s_mgw_name_value_pair, <fs_airports> type zcl_gw100_mp_nn=>airports_t. * Create the output data structure and assign its fields to * the field symbol create data er_entityset type zcl_gw100_mp_nn=>airports_t. assign er_entityset->* to <fs_airports>. * Is there a navigation path that needs to be followed? if it_navigation_path is initial. " Nope, so in this case, we are simply obtaining a " list of all available airports select distinct airpfrom cityfrom countryfr into corresponding fields of table lt_airports from spfli up to is_paging-top rows. else. " Yup, so now we need to read only those airports " that can be reached directly from the current airport. " The current airport is supplied in the it_key_tab table read table it_key_tab assigning <key> index 1. select distinct airpto cityto countryto into corresponding fields of table lt_airports from spfli up to is_paging-top rows where airpfrom = <key>-value. endif. " Transfer the list of airports to the output structure loop at lt_airports assigning <airport rel="nofollow">. " Are we following a navigation path? if it_navigation_path is initial. " Nope, so use the 'from' values lv_airport = <airport rel="nofollow">-airpfrom. lv_country = <airport rel="nofollow">-countryfr. ls_airport-name = <airport rel="nofollow">-cityfrom. else. " Yup, so use the 'to' values lv_airport = <airport rel="nofollow">-airpto. lv_country = <airport rel="nofollow">-countryto. ls_airport-name = <airport rel="nofollow">-cityto. endif. " Populate the output structure ls_airport-iatacode = lv_airport. Continued on next page 214 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read ls_airport-url = zcl_gw100_helper=>get_url_for_airport( airport = lv_airport ). concatenate ls_airport-name '-' lv_airport into ls_airport-title separated by space. ls_airport-geocoordinates-latitude = zcl_gw100_helper=>get_latitude_for_airport( city = ls_airport-name country = lv_country ). ls_airport-geocoordinates-longitude = zcl_gw100_helper=>get_longitude_for_airport( city = ls_airport-name country = lv_country ). append ls_airport to <fs_airports>. endloop. endmethod. e) 4. Save and activate your changes. Implement Method GET_ENTITYSET in the Flight Data Provider Class a) Edit your Flight Data Provider class ZCL_GW100_DP_FLIGHT_nn. b) Create a new private type in this class called FLIGHT_S using the following definition: types: begin of flight_s. include type spfli. types: fldate type sflight-fldate, price type sflight-price, currency type sflight-currency, planetype type sflight-planetype, end of flight_s. c) Change the implementation of method GET_ENTITYSET. d) Replace the entire method with the following code, remembering to update the class names highlighted in yellow: method /iwbep/if_mgw_appl_srv_runtime~get_entityset. data: lt_flights type standard table of flight_s, ls_flight type zcl_gw100_mp_nn=>flight_s, ls_filter_airpto type /iwbep/s_mgw_select_option, ls_filter_fldate type /iwbep/s_mgw_select_option. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 215 Unit 5: OData Channel Data Provider GW100 field-symbols: <flight> type flight_s, <key> type /iwbep/s_mgw_name_value_pair, <so_airpto> type /iwbep/s_mgw_select_option, <so_fldate> type /iwbep/s_mgw_select_option, <fs_flights> type zcl_gw100_mp_nn=>flights_t. create data er_entityset type zcl_gw100_mp_nn=>flights_t. assign: ls_filter_airpto to <so_airpto>, ls_filter_fldate to <so_fldate>, er_entityset->* to <fs_flights>. " Are we following a navigation path? if it_navigation_path is initial. " Nope, so read all the available flights select * into corresponding fields of table lt_flights up to is_paging-top rows from ( spfli as c inner join sflight as f on f~carrid = c~carrid and f~connid = c~connid ). else. " Yup, so apply key field and select options read: table it_key_tab assigning <key> index 1, table it_filter_select_options assigning <so_airpto> with key property = 'AirportTo', table it_filter_select_options assigning <so_fldate> with key property = 'FlightDate'. select * into corresponding fields of table lt_flights up to is_paging-top rows from ( spfli as c inner join sflight as f on f~carrid = c~carrid and f~connid = c~connid ) where c~airpfrom = <key>-value and c~airpto in <so_airpto>-select_options and f~fldate in <so_fldate>-select_options. endif. Continued on next page 216 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read " Transfer all the flight information from the SPFLI "structured table, to the output structured table. loop at lt_flights assigning <flight>. clear ls_flight. ls_flight-airlineid = <flight>-carrid. ls_flight-connectionno = <flight>-connid. ls_flight-flightdate = <flight>-fldate. ls_flight-price = <flight>-price. ls_flight-currencycode = <flight>-currency. ls_flight-distance = <flight>-distance. ls_flight-distanceunit = <flight>-distid. ls_flight-flighttime = <flight>-fltime. ls_flight-planetype = <flight>-planetype. ls_flight-departure-airport = <flight>-airpfrom. ls_flight-departure-city = <flight>-cityfrom. ls_flight-departure-country = <flight>-countryfr. ls_flight-departure-time = <flight>-deptime. ls_flight-arrival-airport = <flight>-airpto. ls_flight-arrival-city = <flight>-cityto. ls_flight-arrival-country = <flight>-countryto. ls_flight-arrival-time = <flight>-arrtime. concatenate `Flight ` ls_flight-airlineid ls_flight-connectionno ` on ` ls_flight-flightdate into ls_flight-title. append ls_flight to <fs_flights>. endloop. endmethod. e) 5. Save and activate your changes. Implement Method GET_ENTITYSET in the Booking Data Provider Class a) Edit your Flight Data Provider class ZCL_GW100_DP_BOOKING_nn. b) Create a new private type in this class called BOOKING_S using the following definition: types: begin of booking_s. types: carrid type sbook-carrid, Continued on next page 2012 © 2012 SAP AG. All rights reserved. 217 Unit 5: OData Channel Data Provider GW100 connid type sbook-connid, fldate type sbook-fldate, bookid type sbook-bookid, customid type sbook-customid, passname type sbook-passname, agencynum type sbook-agencynum, forcuram type sbook-forcuram, forcurkey type sbook-forcurkey, order_date type sbook-order_date, cancelled type sbook-cancelled, end of booking_s. c) Change the implementation of method GET_ENTITYSET. d) Replace the entire method with the following code, remembering to update the class names highlighted in yellow: method /iwbep/if_mgw_appl_srv_runtime~get_entityset. data: lt_bookings type standard table of booking_s, ls_booking type zcl_gw100_mp_nn=>booking_s, lv_carrid type sbook-carrid, lv_connid type sbook-connid, lv_fldate type sbook-fldate, lv_bookid type sbook-bookid, lv_kline type /iwbep/s_mgw_name_value_pair, lv_lines type i. field-symbols: <booking> type booking_s, <fs_bookings> type zcl_gw100_mp_nn=>bookings_t. create data er_entityset type zcl_gw100_mp_nn=>bookings_t. assign er_entityset->* to <fs_bookings>. " Are we following a navigation path? if it_navigation_path is initial. " Nope, so read all available bookings select * into corresponding fields of table lt_bookings up to is_paging-top rows from sbook. else. " Yup, so read only the booking identified by the key values " Were we passed any key values if it_key_tab is not initial. Continued on next page 218 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read " Yup, so see if the key table contains the correct number " of rows describe table it_key_tab lines lv_lines. " Did we find three rows if lv_lines eq 3. " Yup, so search for required key values read table it_key_tab into lv_kline with key name = 'AirlineId'. if sy-subrc = 0. lv_carrid = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'ConnectionNo'. if sy-subrc = 0. lv_connid = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'FlightDate'. if sy-subrc = 0. lv_fldate = lv_kline-value. endif. endif. endif. " If the required key values are not supplied, then the read " will fail and a null result will be passed back to the client. select * into corresponding fields of table lt_bookings up to is_paging-top rows from sbook where carrid = lv_carrid and connid = lv_connid and fldate = lv_fldate. endif. " Transfer the data from the SBOOK data structure to the export " data structure loop at lt_bookings assigning <booking>. clear ls_booking. ls_booking-airlineid = <booking>-carrid. ls_booking-connectionno = <booking>-connid. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 219 Unit 5: OData Channel Data Provider GW100 ls_booking-flightdate = <booking>-fldate. ls_booking-bookingid = <booking>-bookid. ls_booking-customerno = <booking>-customid. ls_booking-customername = <booking>-passname. ls_booking-price = <booking>-forcuram. ls_booking-currencycode = <booking>-forcurkey. ls_booking-bookingdate = <booking>-order_date. concatenate `Booking for ` ls_booking-customername ` on flight ` ls_booking-airlineid ` on ` ls_booking-flightdate ls_booking-connectionno into ls_booking-title. append ls_booking to <fs_bookings>. endloop. endmethod. e) 6. Save and activate your changes. Test the QUERY Operations From A Browser a) If your browser is still pointing to your Flight_Information_nn service, then re-issue the URL for the Service Document. b) If you have closed your browser, then run transaction /IWFND/MAINT_SERVICE. Figure 282: /IWFND/MAINT_SERVICE c) Select your service from the list and press the icon Call Browser. d) Add each of the collection names in turn to your Gateway Service’s Base URL and test that the correct information is returned. Remember that collection names are case-sensitive. Caution: When testing the Bookings collection, please do not simply issue the URL since to return the entire collection – since there are over 28,000 bookings in the system! Instead add the $top query string parameter to limit the result list to say, the first 100 bookings. E.g. http://<server>:<port>/sap/opu/odata/sap/ FLIGHT_INFORMATION_nn/Bookings?$top=100 220 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read Exercise 10: Implement the READ Operation Exercise Objectives After completing this exercise, you will be able to: • Create a Gateway service providing customized flight information Business Example You wish to provide a Gateway service that displays flight information. We now need to implement the GET_ENTITY methods, first for the top level Data Provider class, and then for each of the entity specific Data Provider classes. Task: 2012 1. Implement GET_ENTITY in the Top Level Data Provider Class 2. Implement GET_ENTITY in the Airport Data Provider Class 3. Implement GET_ENTITY in the Flight Data Provider Class 4. Implement GET_ENTITY in the Booking Data Provider Class 5. Test the READ Operations From A Browser © 2012 SAP AG. All rights reserved. 221 Unit 5: OData Channel Data Provider GW100 Solution 10: Implement the READ Operation Task: 1. Implement GET_ENTITY in the Top Level Data Provider Class a) Edit class ZCL_GW100_DP_nn. b) Redefine method GET_ENTITY under interface /IWBEP/IF_MGW_APPL_SRV_RUNTIME. c) Replace the entire method with the following code, remembering to update the class names highlighted in yellow with your own class name. method /iwbep/if_mgw_appl_srv_runtime~get_entity. data: lo_airport type ref to zcl_gw100_dp_airport_nn, lo_flight type ref to zcl_gw100_dp_flight_nn, lo_booking type ref to zcl_gw100_dp_booking_nn. * Implement call-throughs to the specific entity type * data provider classes. * What entity has been requested? Be careful! * Entity names are case sensitive! case iv_entity_name. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * AIRPORT * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * when 'Airport'. create: object lo_airport, data er_entity type zcl_gw100_mp_nn=>airport_s. lo_airport->/iwbep/if_mgw_appl_srv_runtime~get_entity( exporting iv_entity_name = iv_entity_name iv_entity_set_name = iv_entity_set_name iv_source_name = iv_source_name it_key_tab = it_key_tab it_navigation_path = it_navigation_path importing er_entity = er_entity ). * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * FLIGHT * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * when 'Flight'. Continued on next page 222 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read create: object lo_flight, data er_entity type zcl_gw100_mp_nn=>flight_s. lo_flight->/iwbep/if_mgw_appl_srv_runtime~get_entity( exporting iv_entity_name = iv_entity_name iv_entity_set_name = iv_entity_set_name iv_source_name = iv_source_name it_key_tab = it_key_tab it_navigation_path = it_navigation_path importing er_entity = er_entity ). * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * BOOKING * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * when 'Booking'. create: object lo_booking, data er_entity type zcl_gw100_mp_nn=>booking_s. lo_booking->/iwbep/if_mgw_appl_srv_runtime~get_entity( exporting iv_entity_name = iv_entity_name iv_entity_set_name = iv_entity_set_name iv_source_name = iv_source_name it_key_tab = it_key_tab it_navigation_path = it_navigation_path importing er_entity = er_entity ). when others. " Add some other entity handler here endcase. endmethod. d) 2. Save and activate your changes. Implement GET_ENTITY in the Airport Data Provider Class a) Edit class ZCL_GW100_DP_AIRPORT_nn. b) Change the implementation of method GET_ENTITY. c) Replace the entire method with the following code, remembering to update the class names highlighted in yellow with your own class name. method /iwbep/if_mgw_appl_srv_runtime~get_entity. data: lv_country type spfli-countryto. field-symbols: <key> type /iwbep/s_mgw_name_value_pair, Continued on next page 2012 © 2012 SAP AG. All rights reserved. 223 Unit 5: OData Channel Data Provider GW100 <fs_airport> type zcl_gw100_mp_nn=>airport_s. * Create the output data structure and assign its fields to * the field symbol create data er_entity type zcl_gw100_mp_nn=>airport_s. assign er_entity->* to <fs_airport>. " In which airport are we interested? read table it_key_tab assigning <key> index 1. " Read the details of that particular airport from SPFLI select distinct airpfrom cityfrom countryfr into (<fs_airport>-iatacode, <fs_airport>-name, lv_country) from spfli where airpfrom = <key>-value. endselect. " Did we find what we're looking for? if sy-subrc = 0. " Yup <fs_airport>-url = zcl_gw100_helper=>get_url_for_airport( airport = <fs_airport>-iatacode ). concatenate <fs_airport>-name '-' <fs_airport>-iatacode into <fs_airport>-title separated by space. <fs_airport>-geocoordinates-latitude = zcl_gw100_helper=>get_latitude_for_airport( city = <fs_airport>-name country = lv_country ). <fs_airport>-geocoordinates-longitude = zcl_gw100_helper=>get_longitude_for_airport( city = <fs_airport>-name country = lv_country ). endif. endmethod. d) 3. Save and activate your changes. Implement GET_ENTITY in the Flight Data Provider Class a) Edit class ZCL_GW100_DP_FLIGHT_nn. b) Change the implementation of method GET_ENTITY. Continued on next page 224 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read c) Replace the entire method with the following code, remembering to update the class names highlighted in yellow with your own class name. method /iwbep/if_mgw_appl_srv_runtime~get_entity. data: ls_flight type flight_s, lv_carrid type spfli-carrid, lv_connid type spfli-connid, lv_fldate type sflight-fldate, lv_kline type /iwbep/s_mgw_name_value_pair, lv_lines type i. field-symbols: <fs_flight> type zcl_gw100_mp_nn=>flight_s. create data er_entity type zcl_gw100_mp_nn=>flight_s. assign er_entity->* to <fs_flight>. " Have we been passed any key values? if it_key_tab is not initial. " Yup, how many key fields do we have? describe table it_key_tab lines lv_lines. " 3 key fields are needed in order to identify a flight if lv_lines eq 3. read table it_key_tab into lv_kline with key name = 'AirlineId'. if sy-subrc = 0. lv_carrid = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'ConnectionNo'. if sy-subrc = 0. lv_connid = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'FlightDate'. if sy-subrc = 0. lv_fldate = lv_kline-value. endif. endif. endif. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 225 Unit 5: OData Channel Data Provider GW100 " Try to find the required flight select single * into corresponding fields of ls_flight from ( spfli as c inner join sflight as f on f~carrid = c~carrid and f~connid = c~connid ) where f~carrid = lv_carrid and f~connid = lv_connid and f~fldate = lv_fldate. " Did we find it? if sy-subrc = 0. " Yup, transfer fields to output structure <fs_flight>-airlineid = ls_flight-carrid. <fs_flight>-connectionno = ls_flight-connid. <fs_flight>-flightdate = ls_flight-fldate. <fs_flight>-price = ls_flight-price. <fs_flight>-currencycode = ls_flight-currency. <fs_flight>-distance = ls_flight-distance. <fs_flight>-distanceunit = ls_flight-distid. <fs_flight>-flighttime = ls_flight-fltime. <fs_flight>-planetype = ls_flight-planetype. <fs_flight>-departure-airport = ls_flight-airpfrom. <fs_flight>-departure-city = ls_flight-cityfrom. <fs_flight>-departure-country = ls_flight-countryfr. <fs_flight>-departure-time = ls_flight-deptime. <fs_flight>-arrival-airport = ls_flight-airpto. <fs_flight>-arrival-city = ls_flight-cityto. <fs_flight>-arrival-country = ls_flight-countryto. <fs_flight>-arrival-time = ls_flight-arrtime. concatenate `Flight ` <fs_flight>-airlineid <fs_flight>-connectionno ` on ` <fs_flight>-flightdate into <fs_flight>-title. endif. endmethod. d) 4. Save and activate your changes. Implement GET_ENTITY in the Booking Data Provider Class a) Edit class ZCL_GW100_DP_BOOKING_nn and change the implementation of method GET_ENTITY. Continued on next page 226 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read b) Replace the entire method with the following code, remembering to update the class names highlighted in yellow with your own class name. method /iwbep/if_mgw_appl_srv_runtime~get_entity. data: ls_booking type booking_s, lv_carrid type sbook-carrid, lv_connid type sbook-connid, lv_fldate type sbook-fldate, lv_bookid type sbook-bookid, lv_kline type /iwbep/s_mgw_name_value_pair, lv_lines type i. field-symbols: <fs_booking> type zcl_gw100_mp_nn=>booking_s. create data er_entity type zcl_gw100_mp_nn=>booking_s. assign er_entity->* to <fs_booking>. " Have we been passed any key values? if it_key_tab is not initial. " Yup, how many key values are there? describe table it_key_tab lines lv_lines. " 4 key values are needed to locate a booking if lv_lines eq 4. read table it_key_tab into lv_kline with key name = 'AirlineId'. if sy-subrc = 0. lv_carrid = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'ConnectionNo'. if sy-subrc = 0. lv_connid = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'FlightDate'. if sy-subrc = 0. lv_fldate = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'BookingId'. if sy-subrc = 0. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 227 Unit 5: OData Channel Data Provider GW100 lv_bookid = lv_kline-value. endif. endif. endif. " Try reading the booking select single * into corresponding fields of ls_booking from sbook where carrid = lv_carrid and connid = lv_connid and fldate = lv_fldate and bookid = lv_bookid. " Did we find the booking if sy-subrc = 0. " Transfer the data from the SBOOK structure " to the output structure <fs_booking>-airlineid = ls_booking-carrid. <fs_booking>-connectionno = ls_booking-connid. <fs_booking>-flightdate = ls_booking-fldate. <fs_booking>-bookingid = ls_booking-bookid. <fs_booking>-customerno = ls_booking-customid. <fs_booking>-customername = ls_booking-passname. <fs_booking>-price = ls_booking-forcuram. <fs_booking>-currencycode = ls_booking-forcurkey. <fs_booking>-bookingdate = ls_booking-order_date. concatenate `Booking for ` <fs_booking>-customername ` on flight ` <fs_booking>-airlineid ` on ` <fs_booking>-flightdate <fs_booking>-connectionno into <fs_booking>-title. endif. endmethod. c) 5. Save and activate your changes. Test the READ Operations From A Browser a) If your browser is still pointing to your Flight_Information_nn service, then re-issue the URL for the Service Document. b) If you have closed your browser, then run transaction /IWFND/MAINT_SERVICE. Continued on next page 228 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read Figure 283: /IWFND/MAINT_SERVICE c) Select your service from the list and press the icon Call Browser. To test each of the READ operations, you should first perform the QUERY operation, and then select an entity from the entity set. For instance, if we display the Airports collection, we could choose the entry for Frankfurt airport. method /iwbep/if_mgw_appl_srv_runtime~get_entity. data: ls_booking type booking_s, lv_carrid type sbook-carrid, lv_connid type sbook-connid, lv_fldate type sbook-fldate, lv_bookid type sbook-bookid, lv_kline type /iwbep/s_mgw_name_value_pair, lv_lines type i. field-symbols: <fs_booking> type zcl_gw100_mp_nn=>booking_s. create data er_entity type zcl_gw100_mp_nn=>booking_s. assign er_entity->* to <fs_booking>. " Have we been passed any key values? if it_key_tab is not initial. " Yup, how many key values are there? describe table it_key_tab lines lv_lines. " 4 key values are needed to locate a booking if lv_lines eq 4. read table it_key_tab into lv_kline with key name = 'AirlineId'. if sy-subrc = 0. lv_carrid = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'ConnectionNo'. if sy-subrc = 0. lv_connid = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'FlightDate'. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 229 Unit 5: OData Channel Data Provider GW100 if sy-subrc = 0. lv_fldate = lv_kline-value. endif. read table it_key_tab into lv_kline with key name = 'BookingId'. if sy-subrc = 0. lv_bookid = lv_kline-value. endif. endif. endif. " Try reading the booking select single * into corresponding fields of ls_booking from sbook where carrid = lv_carrid and connid = lv_connid and fldate = lv_fldate and bookid = lv_bookid. " Did we find the booking if sy-subrc = 0. " Transfer the data from the SBOOK structure " to the output structure <fs_booking>-airlineid = ls_booking-carrid. <fs_booking>-connectionno = ls_booking-connid. <fs_booking>-flightdate = ls_booking-fldate. <fs_booking>-bookingid = ls_booking-bookid. <fs_booking>-customerno = ls_booking-customid. <fs_booking>-customername = ls_booking-passname. <fs_booking>-price = ls_booking-forcuram. <fs_booking>-currencycode = ls_booking-forcurkey. <fs_booking>-bookingdate = ls_booking-order_date. concatenate `Booking for ` <fs_booking>-customername ` on flight ` <fs_booking>-airlineid ` on ` <fs_booking>-flightdate <fs_booking>-connectionno into <fs_booking>-title. endif. endmethod. The <atom:id rel="nofollow"> tag holds the fully qualified URL for the READ operation. Continued on next page 230 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Read For each entity type, choose an entity from the entity set (or collection), locate the <atom:id rel="nofollow"> tag and issue this URL from your browser address line. This will test the READ operation for each entity type. d) 2012 The key difference between the QUERY and READ operations is this. No matter what filter criteria you define, or whether any entities are found at all, the QUERY operation will always return zero or more entities within an <atom:feed rel="nofollow"> element; whereas, the READ operation will only ever return zero or one entities within an <atom:entry rel="nofollow"> element. © 2012 SAP AG. All rights reserved. 231 Unit 5: OData Channel Data Provider GW100 Lesson Summary You should now be able to: • Understand architectural principles. • Understand the Relationship between HTTP Requests, OData Operations and Methods in the Data Provider Class. • Understand how to implement the QUERY and READ operations. 232 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update Lesson: Developing Data Provider Class for Update Lesson Overview This lesson covers the development of: • • The CREATE operation within a Gateway Data Provider Class A custom OData action Lesson Objectives After completing this lesson, you will be able to: • • Understand how to implement the CREATE operation within a Gateway Data Provider Class. Understand how to implement a custom OData action. Business Example CREATE Operation Figure 284: The CREATE Operation and the Data Model The development of a Gateway Service takes place on whichever system has the IW_BEP component installed. 2012 © 2012 SAP AG. All rights reserved. 233 Unit 5: OData Channel Data Provider GW100 The activation of a Gateway service takes place in whichever SAP system has the GW_CORE component installed. It is entirely possible that these may be different systems. Figure 285: CREATE_ENTITY Method in Top Level Data Provider Class Figure 286: Implement CREATE_ENTITY in the Booking Provider Class 234 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update Custom OData Operation Figure 287: Service Operations - Custom OData Functionality Figure 288: Define a Custom Action - 1/4 2012 © 2012 SAP AG. All rights reserved. 235 Unit 5: OData Channel Data Provider GW100 Figure 289: Define a Custom Action - 2/4 Figure 290: Define a Custom Action - 3/4 Figure 291: Define a Custom Action - 4/4 236 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update Figure 292: Implement EXECUTE_ACTION in Top Level Data Provider Figure 293: Implement EXECUTE_ACTION in the Booking Data Provider 2012 © 2012 SAP AG. All rights reserved. 237 Unit 5: OData Channel Data Provider 238 © 2012 SAP AG. All rights reserved. GW100 2012 GW100 Lesson: Developing Data Provider Class for Update Exercise 11: Implement the CREATE Operation Exercise Objectives After completing this exercise, you will be able to: • Implement and test the Create and CancelBooking operations Business Example To provide the users of the Flight Information service with the ability to create and cancel flight bookings. 2012 © 2012 SAP AG. All rights reserved. 239 Unit 5: OData Channel Data Provider GW100 Task 1: The CREATE_ENTITY method is only appropriate for the Booking entity type; therefore, we only need to implement this method in two places: • The top level Data Provider • The Booking Data Provider Figure 294: Gateway Data Provider 1. Extend the BOOKING_S Data Type and Booking Entity Type in the Model Provider Class 2. Implement Method CREATE_ENTITY in the Top Level Data Provider Class 3. Implement Method CREATE_ENTITY in the Booking Data Provider Class Continued on next page 240 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update Task 2: Test the Booking CREATE_ENTITY Method Before starting the actual test procedure, we must first understand what information is required in order to create a flight booking. In order to create a Booking, five values must be supplied to the BAPI: o AirlineId o Connection No o Flight Date o Customer No o Agency In order to determine which values must be supplied to these fields, we need to look inside some tables in the SAP system. But first… 2012 1. Testing from SAPGUI 2. Testing from the RESTClient in Firefox © 2012 SAP AG. All rights reserved. 241 Unit 5: OData Channel Data Provider GW100 Solution 11: Implement the CREATE Operation Task 1: The CREATE_ENTITY method is only appropriate for the Booking entity type; therefore, we only need to implement this method in two places: • The top level Data Provider • The Booking Data Provider Figure 295: Gateway Data Provider 1. Extend the BOOKING_S Data Type and Booking Entity Type in the Model Provider Class a) Log on to the Gateway Service development system b) Run transaction SE80. c) Edit your Model Provider class ZCL_GW100_MP_nn d) Add two new fields to the booking_s data type: types: begin of booking_s, airlineid type spfli-carrid, Continued on next page 242 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update connectionno type spfli-connid, flightdate type sflight-fldate, bookingid type sbook-bookid, customerno type sbook-customid, customername type sbook-passname, price type sflight-price, currencycode type sflight-currency, bookingdate type sbook-order_date, title type string, agencynum type sbook-agencynum, cancelled type sbook-cancelled, end of booking_s. types: bookings_t type standard table of booking_s. e) In method DEFINE, add these two new fields to the Booking entity type. lo_property = lo_entity_type->create_property( iv_property_name = 'Price' iv_abap_fieldname = 'PRICE' ). lo_property = lo_entity_type->create_property( iv_property_name = 'CurrencyCode' iv_abap_fieldname = 'CURRENCYCODE' ). lo_property = lo_entity_type->create_property( iv_property_name = 'BookingDate' iv_abap_fieldname = 'BOOKINGDATE' ). lo_property = lo_entity_type->create_property( iv_property_name = 'Agency' iv_abap_fieldname = 'AGENCYNUM' ). lo_property = lo_entity_type->create_property( iv_property_name = 'Cancelled' iv_abap_fieldname = 'CANCELLED' ). "Define property Title. Assign it to the ATOM field "Title", "but do not keep it in the content lo_property = lo_entity_type->create_property( iv_property_name = 'Title' iv_abap_fieldname = 'TITLE' ). lo_property->set_as_title( iv_keep_in_content = abap_true ). f) 2. Save and activated these changes Implement Method CREATE_ENTITY in the Top Level Data Provider Class a) Log on to the Gateway Service development system Continued on next page 2012 © 2012 SAP AG. All rights reserved. 243 Unit 5: OData Channel Data Provider GW100 b) Run transaction se80 c) Edit your class ZCL_GW100_DP_nn d) Redefine method /IWBEP/IF_MGW_APPL_SRV_RUNTIME~CREATE_ENTITY. e) Replace the contents of method CREATE_ENTITY with the following code. Be careful to replace the class names highlighted in yellow with the correct name of your Data or Model Provider class method /iwbep/if_mgw_appl_srv_runtime~create_entity. data: lo_booking type ref to /iwbep/if_mgw_appl_srv_runtime, ex_ref type ref to /iwbep/cx_mgw_busi_exception. field-symbols: <fs_booking> type zcl_gw100_mp_nn=>booking_s. " Check to which entity type the request belongs " In this case, we will only respond to create requests for " Booking entity types case iv_entity_name. when 'Booking'. " Create the Booking object and the data structure in " which the booking will be returned create: object lo_booking type zcl_gw100_dp_booking_nn, data er_entity type zcl_gw100_mp_nn=>booking_s. " The booking creation will throw an exception if it fails. " This needs to be caught and handled correctly otherwise " the user will get the very unhelpful error message on " their browser 'An exception was thrown' try. " Try to create the booking lo_booking->create_entity( exporting iv_entity_name = iv_entity_name iv_entity_set_name = iv_entity_set_name iv_source_name = iv_source_name io_data_provider = io_data_provider it_key_tab = it_key_tab it_navigation_path = it_navigation_path importing er_entity = er_entity ). " Has an exception been thrown? Continued on next page 244 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update catch /iwbep/cx_mgw_busi_exception into ex_ref. " Yup, so hijack the TITLE property to use as a carrier " for the error message assign er_entity->* to <fs_booking>. <fs_booking>-title = ex_ref->get_msg_container( ) ->get_leading_message_text( ). endtry. endcase. endmethod. f) 3. Save and activate your changes. Implement Method CREATE_ENTITY in the Booking Data Provider Class a) Edit your Booking Data Provider class ZCL_GW100_DP_BOOKING_nn. b) Change the implementation of method CREATE_ENTITY. c) Replace the entire method with the following code, remembering to update the class names highlighted in yellow: method /iwbep/if_mgw_appl_srv_runtime~create_entity. data: ls_booking type z_cl_gw100_mp_nn=>booking_s, ls_sbook_create type bapisbonew, lt_sbook_create_return type bapirettab, lr_sbook_create_return type ref to bapiret2, lx_busi_exc type ref to /iwbep/cx_mgw_busi_exception. field-symbols: <fs_booking> type zcl_gw100_mp_nn=>booking_s. create data er_entity type zcl_gw100_mp_nn=>booking_s. assign er_entity->* to <fs_booking>. " Read the data supplied by the client call method io_data_provider->read_entry_data importing es_data = ls_booking. ls_sbook_create-airlineid = ls_booking-airlineid. ls_sbook_create-connectid = ls_booking-connectionno. ls_sbook_create-flightdate = ls_booking-flightdate. ls_sbook_create-passname = ls_booking-customername. ls_sbook_create-agencynum = ls_booking-agencynum. ls_sbook_create-customerid = ls_booking-customerno. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 245 Unit 5: OData Channel Data Provider GW100 call function 'BAPI_FLBOOKING_CREATEFROMDATA' exporting booking_data = ls_sbook_create importing airlineid = ls_booking-airlineid bookingnumber = ls_booking-bookingid tables return = lt_sbook_create_return. read table lt_sbook_create_return index 1 reference into lr_sbook_create_return. if lr_sbook_create_return->*-type ne 'S'. create object lx_busi_exc. " Transfer the error message(s) into the exception object lx_busi_exc->get_msg_container( )->add_messages_from_bapi( it_bapi_messages = lt_sbook_create_return ). raise exception lx_busi_exc. else. " Its very important that you commit all successfully " applied changes, otherwise the update will be lost call function 'BAPI_TRANSACTION_COMMIT'. <fs_booking> = ls_booking. endif. endmethod. d) Save and activate your changes Task 2: Test the Booking CREATE_ENTITY Method Before starting the actual test procedure, we must first understand what information is required in order to create a flight booking. In order to create a Booking, five values must be supplied to the BAPI: o AirlineId o Connection No o Flight Date o Customer No o Agency Continued on next page 246 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update In order to determine which values must be supplied to these fields, we need to look inside some tables in the SAP system. But first… 1. Testing from SAPGUI a) From the coding shown above in section 12.2.3, it can be seen that method CREATE_ENTITY in the Booking provider class creates a new flight booking by calling BAPI_FLBOOKING_CREATEFROMDATA. Therefore, in order to test that we are using valid data, we can run the same BAPI in test mode from within the SAP system. b) In a new SAPGUI session, run transaction SE37. (Type /OSE37 into the OK Code field and press enter). c) Enter the name BAPI_FLBOOKING_CREATEFROMDATA and press F8 to execute it. d) Enter an “X” into the input parameter labelled TEST_RUN. e) We now need to determine what values to use for our new flight booking. In a new SAPGUI session, run transaction SE16. (Type /OSE16 into the OK Code field and press enter). f) Look at the contents of table SFLIGHT. g) Choose an arbitrary carrier and flight number. For example, you could select Lufthansa flight 0400. h) Press F3 to return to the SE16 selection screen and filter the display of table SFLIGHT to display only those rows for your chosen flight. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 247 Unit 5: OData Channel Data Provider GW100 Figure 296: Table SFLIGHT i) Choose a flight whose departure date (FLDATE) is in the future and has seats available (where SEATSMAX – SEATSOCC > 0). j) Remember the details of your chosen flight – i.e. the contents of fields CARRID, CONNID and FLDATE. We now have 3 of the 5 required fields for creating a flight booking. k) Press F3 twice to go back to the SE16 start screen. l) Enter the table name SCUSTOM and press enter. m) On the selection screen, press F8 to display the table contents. Since there are over 4000 entries in this table, you will only be shown the first 200. n) Choose any customer number you like (field ID) and remember it. E.G. 00000001. o) The final value we need is an Agency Id. Press F3 twice to return to the SE16 start screen. p) Enter the table name STRAVELAG and press enter followed by F8. q) Choose any agency number you like (field AGENCYNUM) and remember it. E.G. 00000001. Continued on next page 248 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update r) Now that we have all five required values, switch to the SAPGUI screen in which you are test running the BAPI (transaction SE37). s) On the initial screen for running a function module, you will see the names of the input parameters for this function module. Since BOOKING_DATA is not a single field, but a data structure, an icon showing a jigsaw puzzle piece appears to the right of the field name. Figure 297: Import Parameters Click on this icon and enter the values we have just derived. Figure 298: BOOKING_DATA Once these values have been entered, press F3 to return to the initial screen for testing a function module. t) Press F8 to execute the function module. u) In the “Export parameters” section, you should now see the results of a successful test run. Figure 299: Export Parameters Figure 300: Tables Click on the icon next to the “RETURN Result:” table that has 2 entries. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 249 Unit 5: OData Channel Data Provider GW100 You will now see the messages created by the BAPI. Figure 301: Messages This demonstrates that our test data is suitable for creating a flight booking. The reason we did not try to test the suitability of our data from the RESTClient is that when testing from within SAPGUI, we are testing simply the core functionality of the business process, rather than the business functionality plus the XML sent across OData interface. We can now proceed to test our Gateway service in the RESTClient knowing that our test data is valid. 2. Testing from the RESTClient in Firefox a) Open the Firefox browser and start the RESTClient add-on. b) In order to perform a CREATE operation; it is necessary to first perform a READ for two reasons: 1. 2. c) The READ operation supplies us with a suitable XML document that can be modified for the CREATE operation. The READ operation must be used to obtain an X-CSRF-Token without which, UPDATE, DELETE or CREATE operations cannot be performed. From within the RESTClient add-on, issue the URL to display the Bookings collection from your flight information service. Caution: Due to the fact that there are over 28,000 bookings in the backend system, do not request the entire Bookings collection. Instead, restrict the number of returned entities by using the $top query string parameter. E.g. .../Flight_Information_nn/Bookings?$top=100 Continued on next page 250 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update Figure 302: Coding d) In the “Formatted XML” section of the RESTClient, scroll down the list and locate the <atom:id rel="nofollow"> element of some booking (the exact booking you choose is not important). e) Copy the contents of this element to the RESTClient’s address line. f) Add a request header of X-CSRF-Token with a value of Fetch. g) Add the query string parameter sap-ds-debug=true to the URL and send it to the server. h) In the “Rendered XML” section of the RESTClient, click on the SAP icon in the bottom right corner and then select the Response tab. i) Copy the value of the X-CSRF-Token and use this to replace the value “Fetch” in the request header. j) Add a second request header called Content-Type with a value of application/atom+xml;type=entry. k) Change the HTTP method from GET to POST. l) Remove the key predicate and query string from the URL used to perform the READ. The key predicate is the part of the URL immediately after the collection name Bookings enclosed in parentheses. The URL should now contain nothing more than a reference to the Bookings collection. m) Copy the XML in the “Rendered HTML” section to the “Request Body”. This XML will need to be edited before it can be sent to the server as a CREATE request. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 251 Unit 5: OData Channel Data Provider n) In the “Request Body” section of the RESTClient, edit the XML to remove the following: 1. 2. 3. 4. 5. 6. 7. o) GW100 Any hyphen characters and blank lines (this is caused by copying the XML from a formatted display). The <atom:author rel="nofollow"> element The <atom:category rel="nofollow"> element The <atom:id rel="nofollow"> element The <atom:link rel="nofollow"> element The <atom:title rel="nofollow"> element The <atom:updated rel="nofollow"> element Enter your valid data obtained from testing BAPI_FLBOOKING_CREATEFROMDATA into the XML. Your XML should look something like this, where the required values are highlighted in yellow. <atom:entry xml:base= "http://someserver:50009/sap/opu/odata/sap/flight_information_01/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:d= "http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m= "http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" rel="nofollow"> <atom:content type="application/xml" rel="nofollow"> <m:properties> <d:AirlineId>LH</d:AirlineId> <d:ConnectionNo>0400</d:ConnectionNo> <d:FlightDate>2012-06-16T00:00:00</d:FlightDate> <d:BookingId>00000000</d:BookingId> <d:CustomerNo>00000001</d:CustomerNo> <d:CustomerName>Harry Hawk</d:CustomerName> <d:Price>0.00</d:Price> <d:CurrencyCode>EUR</d:CurrencyCode> <d:BookingDate>2012-02-23T00:00:00</d:BookingDate> <d:Agency>00000001</d:Agency> <d:Cancelled m:null="true"/> <d:Title m:null="true"/> </m:properties> </atom:content> </atom:entry> Continued on next page 252 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update Caution: In addition to the values needed to create the flight booking, look at what is also necessary for the XML to be considered valid: • In SP3 of Gateway 2.0, OData properties of type Edm.String are not allowed to be empty. (This constraint will be relaxed in SP4 or can be relaxed in SP3 by applying SAP Note 1690310). Therefore, you must always enter an initial value appropriate for the property’s data type. In the case of Edm.String fields that need to be empty, add the parameter m:null=“true”. E.g. <d:Title m:null=“true”/> • The date is always specified as timestamp in the format YYYY-MM-DDTHH:MM:SS where T is a fixed separator between the date and time parts. If you only need to specify a date, then the time part can be set to 00:00:00. • If you use the m:null=“true” parameter, then you must terminate the empty XML element with a slash character. See the <d:Cancelled> and <d:Title> elements above. p) Once your XML looks correct, press send. q) You should receive an HTTP 201 Created message. Figure 303: Status Code If you receive an error message, then use transaction /IWFND/ERROR_LOG in the Gateway server to see a detailed error message. After the successful creation of the flight booking, you will see within the Response Header section of the RESTClient, a Location parameter followed by a URL. This is the URL to READ the flight booking that has just been created. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 253 Unit 5: OData Channel Data Provider GW100 Unfortunately, the RESTClient does not permit you to follow this link by clicking on it. You can’t even copy and paste the value! To demonstrate that the CREATE operation worked correctly, go to the “Formatted XML” section and look for the <atom:link rel="nofollow"> element. r) Copy the READ operation’s URL inside this element and paste it into the RESTClient’s address line. s) Change the HTTP method from POST to GET and press Send. t) You will now see the XML response of a READ operation on the flight booking you have just created. Keep the READ response in the RESTClient, as this is the booking we will cancel when we come to test the CancelBooking action in the next section. 254 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update Exercise 12: Implement CancelBooking Custom Action Exercise Objectives After completing this exercise, you will be able to: • Implement and test the Create and CancelBooking operations Business Example To provide the users of the Flight Information service with the ability to create and cancel flight bookings. Task: 1. Adjust the Gateway Service’s Metadata 2. Implement Method EXECUTE_ACTION in the Top Level Data Provider Class 3. Implement Method EXECUTE_ACTION in the Booking Data Provider Class 4. Test the CancelBooking Custom Action The OData specification states that all parameters passed to a Service Operation (or Custom Action) must be passed in the query string. This is true irrespective of whether the GET or POST method is used. Also the data types of certain fields must be declared as part of the query string value. 2012 © 2012 SAP AG. All rights reserved. 255 Unit 5: OData Channel Data Provider GW100 Solution 12: Implement CancelBooking Custom Action Task: 1. Adjust the Gateway Service’s Metadata a) Start the ABAP Development Workbench (txn se80) and edit your Model Provider class ZCL_GW100_MP_nn. b) Edit method DEFINE and add declarations for the local objects lo_action and lo_parameter: method DEFINE. Data: lo_entity_type type ref to /iwbep/if_mgw_odata_entity_typ, lo_property type ref to /iwbep/if_mgw_odata_property lo_complex_type type ref to /iwbep/if_mgw_odata_cmplx_type, c) lo_action type ref to /iwbep/if_mgw_odata_action, lo_parameter type ref to /iwbep/if_mgw_odata_parameter. Add the following code to the end of the method: *************************************************************** * CREATE THE CancelBooking ACTION *************************************************************** lo_action = model->create_action( 'CancelBooking' ). lo_action->set_return_entity_type( 'Booking' ). lo_action->set_http_method( 'POST' ). lo_action->set_return_multiplicity( cardinality_entity ). lo_parameter = lo_action->create_input_parameter( iv_parameter_name = 'AirlineId' iv_abap_fieldname = 'AIRLINEID' ). lo_parameter->bind_data_element( 'S_CARR_ID' ). lo_parameter = lo_action->create_input_parameter( iv_parameter_name = 'ConnectionNo' iv_abap_fieldname = 'CONNECTIONNO' ). lo_parameter->bind_data_element( 'S_CONN_ID' ). lo_parameter = lo_action->create_input_parameter( iv_parameter_name = 'FlightDate' iv_abap_fieldname = 'FLIGHTDATE' ). lo_parameter->bind_data_element( 'S_DATE' ). lo_parameter = lo_action->create_input_parameter( iv_parameter_name = 'BookingId' iv_abap_fieldname = 'BOOKINGID' ). lo_parameter->bind_data_element( 'S_BOOK_ID' ). Continued on next page 256 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update endmethod. d) 2. Save and activate your changes. Implement Method EXECUTE_ACTION in the Top Level Data Provider Class a) Edit your top level Data Provider class ZCL_GW100_DP_nn. b) Refine method /IWBEP/IF_MGW_APPL_SRV_RUNTIME~EXECUTE_ACTION. c) Replace the coding this method with the following, remembering to adjust the class names highlighted in yellow: method /IWBEP/IF_MGW_APPL_SRV_RUNTIME~EXECUTE_ACTION. data: lo_booking type ref to /iwbep/if_mgw_appl_srv_runtime, ls_rt_booking type zcl_gw100_mp_nn=>booking_s. " The only action that is responded to is CancelBooking case iv_action_name. when 'CancelBooking'. create: object lo_booking type zcl_gw100_dp_booking_nn, data er_data type zcl_gw100_mp_nn=>booking_s. lo_booking->execute_action( exporting iv_action_name = iv_action_name it_parameter importing er_data = it_parameter = er_data ). endcase. endmethod. d) 3. Save and activate your changes. Implement Method EXECUTE_ACTION in the Booking Data Provider Class a) Edit your Booking Data Provider class ZCL_GW100_DP_BOOKING_nn. b) Change the implementation of method EXECUTE_ACTION. c) Replace the coding in this method with the following, remembering to adjust the class names: method /iwbep/if_mgw_appl_srv_runtime~execute_action. data: wa_booking type sbook, lv_carrid type sbook-carrid, lv_connid type sbook-connid, Continued on next page 2012 © 2012 SAP AG. All rights reserved. 257 Unit 5: OData Channel Data Provider GW100 lv_fldate type sbook-fldate, lv_bookid type sbook-bookid, lv_kline type /iwbep/s_mgw_name_value_pair, lv_lines type i. field-symbols: <fs_booking> type zcl_gw100_mp_nn=>booking_s. " Check what action is being requested if iv_action_name = 'CancelBooking'. create data er_data type zcl_gw100_mp_nn=>booking_s. assign er_data->* to <fs_booking>. " Were we passed any parameters? if it_parameter is not initial. " Yup, how many? describe table it_parameter lines lv_lines. " Must have exactly 4 parameters if lv_lines eq 4. read table it_parameter into lv_kline with key name = 'AirlineId'. if sy-subrc = 0. lv_carrid = lv_kline-value. endif. read table it_parameter into lv_kline with key name = 'ConnectionNo'. if sy-subrc = 0. lv_connid = lv_kline-value. endif. read table it_parameter into lv_kline with key name = 'FlightDate'. if sy-subrc = 0. lv_fldate = lv_kline-value. endif. read table it_parameter into lv_kline with key name = 'BookingId'. if sy-subrc = 0. lv_bookid = lv_kline-value. endif. endif. endif. " Find the booking to be cancelled select single * from sbook into wa_booking where carrid = lv_carrid and connid = lv_connid and fldate = lv_fldate and Continued on next page 258 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update bookid = lv_bookid. " Was the booking found if sy-subrc = 0. " Set the cancelled flag and update the database wa_booking-cancelled = 'X'. update sbook from wa_booking. " Return the details of the cancelled booking to the client. <fs_booking>-airlineid = wa_booking-carrid. <fs_booking>-connectionno = wa_booking-connid. <fs_booking>-flightdate = wa_booking-fldate. <fs_booking>-bookingid = wa_booking-bookid. <fs_booking>-customerno = wa_booking-customid. <fs_booking>-customername = wa_booking-passname. <fs_booking>-agencynum = wa_booking-agencynum. <fs_booking>-price = wa_booking-forcuram. <fs_booking>-currencycode = wa_booking-forcurkey. <fs_booking>-bookingdate = wa_booking-order_date. <fs_booking>-cancelled = wa_booking-cancelled. concatenate `Booking for ` <fs_booking>-customername ` on Flight ` <fs_booking>-airlineid ` on ` <fs_booking>-flightdate <fs_booking>-connectionno ` has been cancelled.` into <fs_booking>-title. else. concatenate `Booking ` lv_bookid ` for flight ` lv_carrid lv_connid ` on ` lv_fldate ` cannot be found.` into <fs_booking>-title. endif. endif. endmethod. d) 4. Save and activate your changes. Test the CancelBooking Custom Action The OData specification states that all parameters passed to a Service Operation (or Custom Action) must be passed in the query string. This is true irrespective of whether the GET or POST method is used. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 259 Unit 5: OData Channel Data Provider GW100 Also the data types of certain fields must be declared as part of the query string value. a) In the RESTClient, delete the following values: 1. 2. The Content-Type request header value The entire request body b) Ensure the HTTP method is set to POST c) Edit the URL so that it contains the following segments concatenated together as a single string: URL Fragment Description flight_information_nn/ Gateway Service name CancelBooking Custom Action name ? Start of query string AirlineId='LH' Quoted string value & Query string separator ConnectionNo='0400' Quoted string value & Query string separator FlightDate=datetime'2012-06-16T00:00' Data type + quoted value & Query string separator BookingId='00009405' Quoted string value The format of the FlightDate parameter is what usually catches people out. This is the OData syntax for declaring that the value in the quoted string is of type Edm.DateTime. No white space is permitted between the data type identifier and the quoted value. The URL for invoking the CancelBooking action will look like the one shown below. The values that you will need to edit have been highlighted in yellow. These should be changed to whatever values describe the booking you are cancelling: flight_information_nn/CancelBooking?AirlineId='LH'& ConnectionNo='0400'& FlightDate=datetime'2012-06-16T00:00'& Bookingld='00009405' Continued on next page 260 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Developing Data Provider Class for Update d) Once you have built the correct URL, press send. You should see an HTTP Status Code of 200 Ok. Figure 304: Status Code e) 2012 The “Formatted XML” response section of the RESTClient will show the XML representation of cancelled flight booking. © 2012 SAP AG. All rights reserved. 261 Unit 5: OData Channel Data Provider GW100 Lesson Summary You should now be able to: • Understand how to implement the CREATE operation within a Gateway Data Provider Class. • Understand how to implement a custom OData action. 262 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Using Associations and Navigation Paths Lesson: Using Associations and Navigation Paths Lesson Overview This lesson covers the use of OData associations and navigation paths. Lesson Objectives After completing this lesson, you will be able to: • • Understand how Entity Types in a Data Model are Related Using Associations. Understand how Associations are Implemented at Runtime Using Navigation Paths. Business Example Associations Figure 305: Turning Data into Information - Using Associations 2012 © 2012 SAP AG. All rights reserved. 263 Unit 5: OData Channel Data Provider GW100 Figure 306: Defining Associations in the Data Model - 1/ The development of a Gateway Service takes place on whichever system has the IW_BEP component installed. The activation of a Gateway service takes place in whichever SAP system has the GW_CORE component installed. It is entirely possible that these may be different systems. Figure 307: Defining Associations in the Data Model - 2/ The development of a Gateway Service takes place on whichever system has the IW_BEP component installed. The activation of a Gateway service takes place in whichever SAP system has the GW_CORE component installed. It is entirely possible that these may be different systems. 264 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Using Associations and Navigation Paths Figure 308: Defining Associations in the Data Model - 3/ The development of a Gateway Service takes place on whichever system has the IW_BEP component installed. The activation of a Gateway service takes place in whichever SAP system has the GW_CORE component installed. It is entirely possible that these may be different systems. Figure 309: Defining Associations in the Data Model - 4/ The development of a Gateway Service takes place on whichever system has the IW_BEP component installed. The activation of a Gateway service takes place in whichever SAP system has the GW_CORE component installed. It is entirely possible that these may be different systems. 2012 © 2012 SAP AG. All rights reserved. 265 Unit 5: OData Channel Data Provider GW100 Figure 310: Creating Associations Navigation Paths Figure 311: Creating Navigation Paths 266 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Using Associations and Navigation Paths Figure 312: Implementing Navigation Paths in the Top Level Data Provider Class 2012 © 2012 SAP AG. All rights reserved. 267 Unit 5: OData Channel Data Provider 268 © 2012 SAP AG. All rights reserved. GW100 2012 GW100 Lesson: Using Associations and Navigation Paths Exercise 13: Create Associations and Navigation Properties Exercise Objectives After completing this exercise, you will be able to: • Allow users to traverse between the entity types in the Flight Information data model. This is achieved by implementing design-time associations and runtime navigation paths in your Gateway service. Business Example To provide the users with the ability to obtain information about business objects related to the one currently selected. This allows the users to get answers to practical questions such as, “If I am starting from a particular airport, to which other airports can I fly directly?” Task: 1. Create Associations Between Entity Types In order to create the real-life associations that exist between related pieces of information, OData provides a facility to create associations. 2. Create Navigation Properties Between Associations The Associations we’ve just created declare nothing more than the existence of an association between certain entity types. In order to make use of these associations, we need to provide the user with a means of navigating from one side of an association to the other. This is where Navigation Properties are used. 3. Modify method GET_ENTITYSET in the Top Level Data Provider Class So far, the coding in method GET_ENTITYSET of the top level Data Provider class takes a simplistic view of the requests it receives. It examines only the name of the entity set (or collection), and then simply calls the associated Data Provider class for that entity type. This coding is not suitable for handling navigation paths for the simple reason that if you want to see a list of flights that depart from a given airport, the URL will refer to the Airports collection, but the returned entity type should be a collection of flights, not airports. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 269 Unit 5: OData Channel Data Provider GW100 Therefore, we need to extend the coding in the GET_ENTITYSET method to call the Data Provider class associated with the entity type being returned – which is not necessarily the same entity type identified by the collection name. 4. Test Navigation Paths in the Browser Three navigation paths need to be tested: • AirportsTo: For any given airport, we can list the airport to which we can fly directly. • DepartingFlights: For any given airport, we can list the flights that take from there. • Bookings: For any given flight, we can list its bookings. Navigation paths are tested by constructing a URL that identifies a specific airport or flight, and then appending to it the navigation path name. 270 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Using Associations and Navigation Paths Solution 13: Create Associations and Navigation Properties Task: 1. Create Associations Between Entity Types In order to create the real-life associations that exist between related pieces of information, OData provides a facility to create associations. a) Start the ABAP Development Workbench (transaction SE80) and edit your Model Provider class ZCL_GW100_MP_nn. b) Edit method DEFINE and add a declaration for the local object lo_association: method DEFINE. Data: lo_entity_type type ref to /iwbep/if_mgw_odata_entity_typ, lo_property type ref to /iwbep/if_mgw_odata_property lo_complex_type type ref to /iwbep/if_mgw_odata_cmplx_type, c) lo_action type ref to /iwbep/if_mgw_odata_action, lo_parameter type ref to /iwbep/if_mgw_odata_parameter, lo_association type ref to /iwbep/if_mgw_odata_assoc. Add the following coding to the end the method. ***************************************************************** * ASSOCIATIONS ***************************************************************** "Define Association AirportFrom_AirportsTo between Airport and "Airport lo_association = model->create_association( iv_association_name = 'AirportFrom_AirportsTo' iv_left_type = 'Airport' iv_right_type = 'Airport' iv_right_card = cardinality_feed iv_left_card = cardinality_entity ). "Define Association AirportFrom_DepartingFlights between Airport "and Flight lo_association = model->create_association( iv_association_name = 'AirportFrom_DepartingFlights' iv_left_type = 'Airport' iv_right_type = 'Flight' iv_right_card = cardinality_feed iv_left_card = cardinality_entity ). Continued on next page 2012 © 2012 SAP AG. All rights reserved. 271 Unit 5: OData Channel Data Provider GW100 "Define Association Flight_Bookings between Flight and Booking lo_association = model->create_association( iv_association_name = 'Flight_Bookings' iv_left_type = 'Flight' iv_right_type = 'Booking' iv_right_card = cardinality_feed iv_left_card = cardinality_entity ). Three associations are created here: • • • 2. An association showing which airports can be reached from any other airport. An association showing which flights are departing from a particular airport. An association showing the bookings for a particular flight. d) Save and activate your changes. e) Go back to the browser and re-issue the $metadata URL. f) You will now see various extra elements in the XML – three <Association rel="nofollow"> elements, and within the <EntityContainer> element, three new <AssociationSet rel="nofollow"> elements. Create Navigation Properties Between Associations Continued on next page 272 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Using Associations and Navigation Paths The Associations we’ve just created declare nothing more than the existence of an association between certain entity types. In order to make use of these associations, we need to provide the user with a means of navigating from one side of an association to the other. This is where Navigation Properties are used. a) b) Edit method DEFINE. Add the following coding to the end the method. ****************************************************************** * NAVIGATION PROPERTIES ****************************************************************** "Navigation Properties for entity Airport lo_entity_type = model->get_entity_type( iv_entity_name = 'Airport' ). "Add Navigation Property from role AirportFrom "to role AirportsTo lo_entity_type->create_navigation_property( iv_property_name = 'AirportsTo' iv_association_name = 'AirportFrom_AirportsTo' ). "Add Navigation Property from role AirportFrom "to role DepartingFlights lo_entity_type->create_navigation_property( iv_property_name = 'DepartingFlights' iv_association_name = 'AirportFrom_DepartingFlights' ). "Navigation Properties for entity Flight lo_entity_type = model->get_entity_type( iv_entity_name = 'Flight' ). "Add Navigation Property from role Flight to role Bookings lo_entity_type->create_navigation_property( iv_property_name = 'Bookings' iv_association_name = 'Flight_Bookings' ). Note: Notice that these statements operate on the entity types for Airport and Booking, not the entity sets Airports and Bookings. A navigation property is identified by the value of the iv_property_name parameter, and then given an association on which to operate. c) Save and activate your changes. d) Go back to the browser and re-issue the $metadata URL. e) You will now see some new <NavigationProperty> elements within the <EntityType> elements for Flight and Airport. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 273 Unit 5: OData Channel Data Provider 3. GW100 Modify method GET_ENTITYSET in the Top Level Data Provider Class So far, the coding in method GET_ENTITYSET of the top level Data Provider class takes a simplistic view of the requests it receives. It examines only the name of the entity set (or collection), and then simply calls the associated Data Provider class for that entity type. This coding is not suitable for handling navigation paths for the simple reason that if you want to see a list of flights that depart from a given airport, the URL will refer to the Airports collection, but the returned entity type should be a collection of flights, not airports. Therefore, we need to extend the coding in the GET_ENTITYSET method to call the Data Provider class associated with the entity type being returned – which is not necessarily the same entity type identified by the collection name. a) Edit your top level Data Provider class ZCL_GW100_DP_nn. Since there are no navigation paths related to the Booking entity type, we only need to adjust the coding for Airports and Flights. b) Just after the data declaration, declare a field symbol: field-symbols: c) <fs_nav_path> type /iwbep/s_mgw_navigation_path. Replace the case branch for Airports with the following, remembering to adjust the class names highlighted in yellow: when 'Airports'. " First check for navigation paths that require a different " entity set to be returned than the one indicated by the " collection name. E.G. Airports('FRA')/DepartingFlights " contains Airports as the entity set but requires a " collection of Flights to be returned read table it_navigation_path assigning <fs_nav_path> index 1. " Instantiate the data provider object for this entity set if sy-subrc = 0 and <fs_nav_path>-nav_prop = 'DepartingFlights'. create: object lo_flight, data er_entityset type z_cl_gw100_mp_nn=>flights_t. lo_flight->/iwbep/if_mgw_appl_srv_runtime~get_entityset( exporting iv_entity_name = iv_entity_name iv_source_name = iv_source_name iv_entity_set_name = iv_entity_set_name it_filter_select_options = it_filter_select_options it_order = it_order is_paging = is_paging Continued on next page 274 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Using Associations and Navigation Paths it_navigation_path importing = it_navigation_path it_key_tab = it_key_tab iv_filter_string = iv_filter_string iv_search_string = iv_search_string er_entityset = er_entityset ). else. create: object lo_airport, data er_entityset type z_cl_gw100_mp_nn=>airports_t. lo_airport->/iwbep/if_mgw_appl_srv_runtime~get_entityset( exporting iv_entity_name = iv_entity_name iv_source_name = iv_source_name iv_entity_set_name = iv_entity_set_name it_filter_select_options = it_filter_select_options it_order = it_order is_paging = is_paging it_navigation_path = it_navigation_path it_key_tab = it_key_tab iv_filter_string = iv_filter_string iv_search_string importing er_entityset = iv_search_string = er_entityset ). endif. d) Replace the case branch for Flights with the following, remembering to adjust the class names highlighted in yellow: when 'Flights'. " First check for navigation paths that require a different " entity set to be returned than the one indicated by the " collection name. E.G. Flights(AirlineId='JL', " ConnectionNo='0408',FlightDate='20110423')/Bookings contains " Flights as the entity set but requires a collection of " Bookings to be returned read table it_navigation_path assigning <fs_nav_path> index 1. " Instantiate the data provider object for this entity set if sy-subrc = 0 and <fs_nav_path>-nav_prop = 'Bookings'. create: object lo_booking, data er_entityset type z_cl_gw100_mp_nn=>bookings_t. lo_booking->/iwbep/if_mgw_appl_srv_runtime~get_entityset( exporting iv_entity_name = iv_entity_name iv_source_name = iv_source_name Continued on next page 2012 © 2012 SAP AG. All rights reserved. 275 Unit 5: OData Channel Data Provider GW100 iv_entity_set_name = iv_entity_set_name it_filter_select_options = it_filter_select_options it_order = it_order is_paging = is_paging it_navigation_path = it_navigation_path it_key_tab = it_key_tab iv_filter_string = iv_filter_string iv_search_string importing er_entityset = iv_search_string = er_entityset ). else. create: object lo_flight, data er_entityset type z_cl_gw100_mp_nn=>flights_t. lo_flight->/iwbep/if_mgw_appl_srv_runtime~get_entityset( exporting iv_entity_name = iv_entity_name iv_source_name = iv_source_name iv_entity_set_name = iv_entity_set_name it_filter_select_options = it_filter_select_options it_order = it_order is_paging = is_paging it_navigation_path = it_navigation_path it_key_tab = it_key_tab iv_filter_string = iv_filter_string iv_search_string importing er_entityset = iv_search_string = er_entityset ). endif. e) 4. Save and activate your changes. Test Navigation Paths in the Browser Three navigation paths need to be tested: • AirportsTo: For any given airport, we can list the airport to which we can fly directly. • DepartingFlights: For any given airport, we can list the flights that take from there. • Bookings: For any given flight, we can list its bookings. Continued on next page 276 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Using Associations and Navigation Paths Navigation paths are tested by constructing a URL that identifies a specific airport or flight, and then appending to it the navigation path name. a) List all the Airports by issuing the URL for the Airports collection. b) Choose a specific airport and look for the <atom:link rel="nofollow"> elements within that <atom:entry rel="nofollow">. In our case, there will be three <atom:link rel="nofollow"> elements, the first one is a self reference, and the next two show the relative URLs for each navigation path. Figure 313: Coding 2012 c) Issue the URLs for the AirportsTo and DepartingFlights navigation paths. You will see a subset of the list of airports and a subset of the list of flights respectively. d) Similarly, select an individual flight, and then issue the Booking navigation path for that one flight. You will then see a list of all the bookings for that flight. © 2012 SAP AG. All rights reserved. 277 Unit 5: OData Channel Data Provider GW100 Lesson Summary You should now be able to: • Understand how Entity Types in a Data Model are Related Using Associations. • Understand how Associations are Implemented at Runtime Using Navigation Paths. 278 © 2012 SAP AG. All rights reserved. 2012 GW100 Unit Summary Unit Summary You should now be able to: • Understand architectural principles. • Understand the Relationship between HTTP Requests, OData Operations and Methods in the Data Provider Class. • Understand how to implement the QUERY and READ operations. • Understand how to implement the CREATE operation within a Gateway Data Provider Class. • Understand how to implement a custom OData action. • Understand how Entity Types in a Data Model are Related Using Associations. • Understand how Associations are Implemented at Runtime Using Navigation Paths. 2012 © 2012 SAP AG. All rights reserved. 279 Unit Summary 280 GW100 © 2012 SAP AG. All rights reserved. 2012 Unit 6 Front-end Application Development Unit Overview In this unit, you will learn about the wide range of possibilities available to you when needing to consume a Gateway service. The two exercises deal with two commonly used consumption scenarios – Java and JavaScript. Unit Objectives After completing this unit, you will be able to: • • • The general principles of consuming a Gateway Service. Creation of OData proxy objects. Consumption of Gateway Services using Java Server Pages and JavaScript + HTML5. Unit Contents Lesson: Consuming Gateway Services......................................282 Exercise 14: Consume a Gateway Service Using Java Server Pages ........................................................................293 Exercise 15: Consume a Gateway Service using the SAP UI5 JavaScript Libraries ........................................................305 2012 © 2012 SAP AG. All rights reserved. 281 Unit 6: Front-end Application Development GW100 Lesson: Consuming Gateway Services Lesson Overview This lesson covers: • • • • The general principles of consuming a Gateway Service Creation of OData proxy objects Creating an iPhone Application to Consume a Gateway Service Consumption of Gateway Services using Java Server Pages and JavaScript + HTML5 Lesson Objectives After completing this lesson, you will be able to: • • • The general principles of consuming a Gateway Service. Creation of OData proxy objects. Consumption of Gateway Services using Java Server Pages and JavaScript + HTML5. Business Example Gateway Service Consumption Overview Figure 314: My Gateway Service Works… Now What? 282 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 315: Gateway Service Consumption - Where to Start? 1/2 Since the field is wide open here, the only recommendation SAP makes is that if you wish to consume a Gateway Service from a mobile device, that you should use the Sybase Unwired Platform software. However, if the SUP software does not provide a good fit for your specific use case, then you are at liberty to choose any programming language and software environment with which you are comfortable and that meets your needs. Figure 316: Gateway Service Consumption - General Principles 2012 © 2012 SAP AG. All rights reserved. 283 Unit 6: Front-end Application Development GW100 Creating OData Proxy Objects Figure 317: Gateway Service Consumption - Proxy Generation Figure 318: Gateway Proxy Generation - Eclipse (Java or PHP) 284 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 319: Gateway Proxy Generation - Visual Studio 2010 (C#) Figure 320: Gateway Proxy Generation - Flash Builder ≥4.5 (MXML) 2012 © 2012 SAP AG. All rights reserved. 285 Unit 6: Front-end Application Development GW100 Figure 321: Gateway Proxy Generation - XCode (Objective C) 1/2 Figure 322: Gateway Proxy Generation - XCode (Objective C) 2/2 286 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 323: Gateway Proxy Generation - SAPUI5 (JavaScript+HTML5) iPhone App Creation Figure 324: Creating a Basic iPhone Application - 1/11 2012 © 2012 SAP AG. All rights reserved. 287 Unit 6: Front-end Application Development GW100 Figure 325: Creating a Basic iPhone Application - 2/11 Figure 326: Creating a Basic iPhone Application - 3/11 288 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 327: Creating a Basic iPhone Application - 4/11 Figure 328: Creating a Basic iPhone Application - 5/11 2012 © 2012 SAP AG. All rights reserved. 289 Unit 6: Front-end Application Development GW100 Figure 329: Creating a Basic iPhone Application - 6/11 Figure 330: Creating a Basic iPhone Application - 7/11 290 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 331: Creating a Basic iPhone Application - 8/11 Figure 332: Creating a Basic iPhone Application - 9/11 2012 © 2012 SAP AG. All rights reserved. 291 Unit 6: Front-end Application Development GW100 Figure 333: Creating a Basic iPhone Application - 10/11 Figure 334: Creating a Basic iPhone Application - 11/11 292 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Exercise 14: Consume a Gateway Service Using Java Server Pages Exercise Objectives After completing this exercise, you will be able to: • Create a Java Server Page based application that consumes the generated Gateway Bank service created in exercises 2 and 3. Business Example To provide the users with the ability to obtain and manipulate Bank information from a browser based application. Task: Preliminary Information: In order to complete this exercise, you must first have successfully generated the Gateway Service ZBANK_INFO_nn where nn is your group number. 2012 1. Application Architecture Information 2. Implement the Logon JSP Page 3. Implement the Bank List JSP Page 4. Implement the Bank Get Details JSP Page 5. Implement the Bank Update JSP Page 6. Implement the Bank Create JSP Page © 2012 SAP AG. All rights reserved. 293 Unit 6: Front-end Application Development GW100 Solution 14: Consume a Gateway Service Using Java Server Pages Task: Preliminary Information: In order to complete this exercise, you must first have successfully generated the Gateway Service ZBANK_INFO_nn where nn is your group number. 1. Application Architecture Information a) The JSP application you will modify has the following architecture. Figure 335: Architecture You will be performing most of your development work in the BankModel.java file; however, apart from login.jsp, each of the JSP pages makes a reference to a Java proxy class that you will generate. These references needed to be updated once you have generated the proxy classes. 2. Implement the Logon JSP Page a) Start Eclipse using the Eclipse – SAPUI5 shortcut in your N:\My Documents folder. Please do not use any other Eclipse installation that is accessible from the Windows Start menu. b) You will see that a solution for this exercise already exists as project GW100_Bank_JSP_Solution. This solution can be run immediately and points to the Gateway service ZBANK_INFO_00. c) Expand the template exercise project GW100_Bank_JSP_Ex. You will notice that there are several files that contain errors. These errors are due to the fact that the proxy object used to communicate with Gateway is missing. d) Select the project name GW100_Bank_JSP_Ex and press Ctrl-N. Continued on next page 294 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 336: Project Explorer e) In the pop-up window, select SAP NetWeaver Gateway → Proxy Generation and press Next. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 295 Unit 6: Front-end Application Development GW100 Figure 337: Select a Wizard f) Now select Java SE from the drop down list in the section Create a new proxy for. This will cause an input field to appear in which the package name of the generated proxy class is to be entered. Press the browse button and select com.sap.training.gw100.proxy. Figure 338: Java SE g) On the next screen, press the Catalog button and then select system ZME from the SAP NetWeaver Gateway connection: drop down list. A few seconds later, you will see a list of all the services available in that Gateway system. Continued on next page 296 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 339: List of Services h) Scroll down the list of services on the left side of the screen and select your Z_BANK_INFO_nn service. Before pressing OK, it is worth checking that you do not have any unwanted data structures in the interface. Expand the structure underneath your ZBANK_INFO_nn service and check that you have only one collection (which will typically be called z_gw100_rfm_bank_nnCollection). If any extra items appear (say BANK_DETAIL or BANK_ADDRESS etc), then you have either left an unwanted data structure in your interface, or you have forgotten to flatten all the fields in your interface. If this is the case, then you need to go back to the mapping definition of your generated Gateway service and remove any data structures. i) Press OK and then Finish. Two Java classes to be created: one class is generated for the actual service, and one class is generated for each of the collections available via that service. j) Expand src → com.sap.training.gw100.model and open the file BankModel.java. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 297 Unit 6: Front-end Application Development k) GW100 You must now add the coding to connect to the SAP NetWeaver Gateway system. In method login(), you will see a TODO comment marker. After the declaration of the null IRestClient object, add the following coding: Figure 340: Coding You must insert the correct hostname, port and client of the Gateway server, and you must also ensure that your own Gateway service proxy class is referenced. These are highlighted in yellow above. l) Check that the correct import statements are being used. The quickest way to do this is to press Ctrl-Shift-O (letter “O”). This runs the Organise Imports command whichs adds missing import statements and removes unused import statements. m) There are several references throughout the BankModel.java file to class z_gw100_rfm_bank_00. This is the class used in the sample solution. You need to alter these references to point to your own proxy class. n) Save BankModel.java. o) We are now ready to test the log in functionality. p) Expand the Servers node in your workspace and select Tomcat v7.0 Server at localhost-config. Press F5 to synchronise the workspace entries with the file system. This step is only needed once. q) Expand the branch WebContent. With login.jsp selected, press the Run button on the tool bar. A local Tomcat server will now be started and you will see the login screen appear within Eclipse. r) Enter your userid and password and press Login. Continued on next page 298 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 341: Login s) If successful. You will see the next screen in which you are asked to select a country. Figure 342: Login – Country Continued on next page 2012 © 2012 SAP AG. All rights reserved. 299 Unit 6: Front-end Application Development 3. GW100 Implement the Bank List JSP Page a) Open file BankModel.java file again and locate the getList() method. b) Add the following coding after the declaration of the null List object Figure 343: Coding Make sure that your own generated proxy class is referenced correctly: • • In the method’s signature In the highlighted references above c) Save your changes and test the bank list functionality. In order to do this, you must always start from the log in page. d) After logging on and selecting a country, you should now see a list of banks. Figure 344: List of Banks Continued on next page 300 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services 4. Implement the Bank Get Details JSP Page a) Open file BankModel.java file again and locate the getDetails() method. b) Add the following coding after the declaration of the null bankList. Figure 345: Bank Details Make sure that your own generated proxy class is referenced correctly: • • In the method’s signature In the highlighted references above c) Save your changes and test the bank detail functionality. In order to do this, you must always start from the log in page. d) Repeat the log on and country selection process. Choose a bank from the list to see its details. Figure 346: Coding Continued on next page 2012 © 2012 SAP AG. All rights reserved. 301 Unit 6: Front-end Application Development 5. GW100 Implement the Bank Update JSP Page a) Open file BankModel.java file again and locate the update() method. b) Add the following coding Figure 347: Coding Make sure that your own generated proxy class is referenced correctly: • • In the method’s signature In the highlighted references above c) Save your changes and test the bank update functionality. In order to do this, you must always start from the log in page. d) Repeat the log on and country selection process. Choose a bank from the list to see its details, then modify those details and press the Update button. e) Once you see the Bank has been successfully updated message, press the back button to return to the list of banks. If you changed the Bank’s name, you will now see the change in the list. Continued on next page 302 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services 6. Implement the Bank Create JSP Page a) Open file BankModel.java file again and locate the update() method. b) Add the following coding. Figure 348: Coding Make sure that your own generated proxy class is referenced correctly: • • 2012 In the method’s signature In the highlighted references above c) Save your changes and test the bank create functionality. In order to do this, you must always start from the log in page. d) Repeat the log on and country selection process. On the bank list screen, press the Create Bank link at the top of the screen. e) Enter some data for a new bank. The length of the bank id varies depending on the country you have selected. For the US, the bank id must be a 9 digit number, but for Germany, it is an 8 digit number. Also, if you choose Germany (country code DE), then do not enter a value in the Region field. f) After pressing the Create button, you should see a message saying Bank has been created successfully. g) Return to the list of banks and you will see your newly created bank in the list. © 2012 SAP AG. All rights reserved. 303 Unit 6: Front-end Application Development 304 © 2012 SAP AG. All rights reserved. GW100 2012 GW100 Lesson: Consuming Gateway Services Exercise 15: Consume a Gateway Service using the SAP UI5 JavaScript Libraries Exercise Objectives After completing this exercise, you will be able to: • Create a JavaScript based application that consumes the custom written Gateway Flight Information service created in exercises 5 to 13. Business Example To provide the users with the ability to obtain and manipulate Flight information from a browser based application. Task: In order to complete this exercise, you must first have successfully built the Gateway Service Flight_Information_nn where nn is your group number. 2012 1. Create a BSP Application 2. Create an ICF Node for the BSP Application 3. Create an SAP UI5 Application in Eclipse 4. Edit the UI5 Views, Controllers and Model 5. Start building the index.html page 6. Publish the Project to the SAP Server element containing the following code: 7. Add Content to the Shell © 2012 SAP AG. All rights reserved. 305 Unit 6: Front-end Application Development GW100 Solution 15: Consume a Gateway Service using the SAP UI5 JavaScript Libraries Task: In order to complete this exercise, you must first have successfully built the Gateway Service Flight_Information_nn where nn is your group number. 1. Create a BSP Application a) In this exercise, you will consume a Gateway service from a basic (read-only) HTML5 and JavaScript application.You will develop this application in Eclipse and publish it directly into the NetWeaver Gateway server. Building a project this way means that the NetWeaver server on which Gateway has been installed will act not only as the supplier of OData services, but also as the web server. In order to allow files to be published into the NetWeaver server, you must first create a BSP application to act as a container for the published files. Logon to the ABAP system in which your FLIGHT_INFORMATION_nn service was developed. b) In transaction SE80, create a BSP Application called ZGW100_UI5_nn where nn is your group number. Caution: BSP Application names are limited to 15 characters. Figure 349: BSP Application c) Double click on your BSP application name and switch to change mode. d) Select the Properties tab and enter /ui/cl_ui5_bsp_application as the Application Class. Continued on next page 306 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 350: Application Class e) 2. Save and activate the BSP application Create an ICF Node for the BSP Application a) Run transaction SICF. b) Enter a service path of /sap/bc/ui5_ui5/sap and apply the filter. Figure 351: /sap/bc/ui5_ui5/sap c) Right-click on node sap and select New sub-element. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 307 Unit 6: Front-end Application Development d) GW100 The ICF node must have the same as the BSP application – ZGW100_UI5_nn – and press the green tick icon. Figure 352: ZGW100_UI5_nn 3. e) Right-click on your new ICF node and select Activate from the menu. f) Confirm the activation. The preparation steps are now complete for publishing an SAP UI5 application into the SAP system of the name ZGW100_UI5_nn. Create an SAP UI5 Application in Eclipse a) Use the Eclipse – SAP UI5 icon in the N:\My Documents directory to start Eclipse. In the Eclipse workspace, there is already a sample solution for this application. b) Press Ctrl-N and select SAP UI5 Application → SAP UI5 Application Project. Continued on next page 308 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 353: SAP UI5 Application c) The SAP UI5 project must have the same name as the ICF Node you created, which in turn has the same name as the BSP Application.Enter zgw100_ui5_nn and don’t switch off the Create an initial view check box. Press Next. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 309 Unit 6: Front-end Application Development GW100 Figure 354: zgw100_ui5_nn d) Append /views to the Folder name – WebContent/zgw100_ui5_nn/views e) Enter a view name of showFlights and press Finish. Figure 355: showFlights f) Three files have been created – index.html, showFlights.controller.js and showFlights.view.js. g) Create two more views by pressing Ctrl-N and selecting SAP UI5 Application → SAP UI5 Application View Continued on next page 310 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 356: Application View h) 4. Calls the views showAirports and showBookings and do not forget to create these views in your /views folder! Edit the UI5 Views, Controllers and Model a) Expand the sample solution for this exercise GW100_UI5_Sol → WebContent → gw100_ui5_sol. b) In addition to seeing the views directory, you will also see a models directory. Hold down Ctrl and drag the models directory from the solution and drop it on your zgw100_ui5_nn directory. You will be asked to select how the folder should be imported into your project.Select Copy files and folders. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 311 Unit 6: Front-end Application Development GW100 Figure 357: Copy Files and Folders c) Expand the views directory in the solution, and you will see an extra file called ui_utilities.js.Copy this file by holding down Ctrl and dragging it into your own views directory.In the pop-up window, select that you want to copy the file. Figure 358: Copy File d) Expand the models directory in your project and open flightInfoModel.js. Figure 359: Coding Continued on next page 312 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services You must edit the highlighted sections and enter your own values for the service name, userid and password. e) The following 2 steps each need to be performed three times.Step 1 for each of the showAirports, showFlights and showBookings controllers and step b) for the views. 1. Open file show<entity_type>.controller.js and add a new method by entering the underlined text shown below. Figure 360: Coding Change the entity type name highlighted in yellow for each of the Airports, Flights and Bookings controllers. Be careful to enter each entity type name correctly!Entity type names are case-sensitive.Also, the controller name uses the plural of the entity type name, whereas the new method name and the value it returns are singular. This function is necessary so that each view controller can return the name of the entity type it is responsible for displaying. 2. Open file show<entity_type>.view.js and add the underlined statement. Figure 361: Coding Make sure that in the parameter list to the buildTableFromMetadata() function, you are calling the correct get<entity_type>.entityname() method. Change the highlighted entity type name for the appropriate name remembering about case-sensitivity. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 313 Unit 6: Front-end Application Development GW100 The function buildTableFromMetadata() is found within the ui_utilities.js file that you copied from the sample solution. 5. Start building the index.html page a) So far we have assembled the pieces needed to run an SAP UI5 application.We now need to join these pieces together so that they function as an application. This functionality will be contained within the single web page index.html. Open the index.html file.You will find that stub code has been generated that contains the instructions needed to load the SAP UI5 libraries. b) Press Ctrl-Shift-F to format the code.This is simply to reduce the width of the indented code. c) The first thing to do is to instruct SAP UI5 that you will require the use of the sap.ui.table and sap.ui.ux3 libraries. Figure 362: Coding d) Next, the model object must be initialised and the ui_utilities.js library referenced by including <script> tags that point to these JavaScript files. After the tag </script> for the above coding, add the coding below making sure you enter the correct path names for your project. Figure 363: Coding e) Immediately after this, you should have another <script> element containing the following code: Figure 364: Coding Do not delete the call to sap.ui.localResources() but delete everything else highlighted in yellow. Continued on next page 314 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Figure 365: Coding f) Now comes the part where we define the screen layout by using a Shell object.This object defines the left hand, top and right hand navigation areas and a central content area. g) Immediately after the call to sap.ui.localResources() add the following code, making sure you correct the names highlighted in yellow for your project. Figure 366: Coding On its own, this defines nothing more than an empty shell.However, it is a good starting point for understanding the structure of the screen. We area nearly ready to make an initial test of this application, but first we need to do two things: firstly, add the line of code that places the shell object on the screen, and secondly, to publish the application into the SAP server. h) Add the following line of code immediately before the </script> tag Figure 367: Coding 6. Publish the Project to the SAP Server element containing the following code: a) Even though our project is incomplete, it is sufficiently functional to be able to see the empty shell object on the screen. But first we need to publish out project to the web server (i.e. the SAP NetWeaver Gateway server). 1) In Eclipse, save all open files by pressing Ctrl-Shift-S Continued on next page 2012 © 2012 SAP AG. All rights reserved. 315 Unit 6: Front-end Application Development GW100 b) In the Project Explorer view to the left of your screen, right click on your SAP UI5 project name and select Team → Share Project. c) This will open a pop-up window in which you are asked to identify to which type of repository you would like to publish the project. Figure 368: Project Publishing 1/2 Figure 369: Project Publishing 2/2 d) Select SAP UI5 Repository and press Next. Continued on next page 316 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services e) Now select the correct SAP system and press Next. f) Enter your userid and password and press Next. g) You will now see a list of all BSP Applications within the SAP system that have /ui/cl_ui5_bsp_application as their application class. Please make sure you choose your own BSP Application – not someone else’s! Caution: The SAP Server Connectivity plug-in does not check to see whether the BSP Application has an associated ICF node.This is because an ICF Node is treated as a runtime entity, whereas the SAP UI5 application you are publishing and its associated BSP Application are treated as a design time entities. Figure 370: BSP Application h) Press Finish.All that has happened is that you have identified to the SAP system that the contents of your SAP UI5 project are, at some point in the future, going to be shared.However, no file sharing has yet taken place! The Share Project step is a one-off preparatory step that does not now need to be repeated. i) Right-click again on your project and select Team → Submit. Click through the screens and you will see a list that shows which files in you project need to be synchronized. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 317 Unit 6: Front-end Application Development GW100 Since this is the first time you have submitted the project, all the files will be transferred. Figure 371: Submit the Project j) In SAPGUI, logon on to the training system again and run transaction SICF. k) Enter a service path of /sap/bc/ui5_ui5/sap/ and apply the filter. l) Right click on your BSP Application and select Test Service. m) You should now see an empty shell appear in your browser. Figure 372: Browser n) 7. The shell is not quite as dull as it appears!Click on the PEOPLE side bar and notice that firstly, the content area animates as the new navigation area is exposed, and secondly, you didn’t have to write any coding to create this functionality.Similarly, look at the Search, Open Recent Items and Feeder icons on the left. Add Content to the Shell Continued on next page 318 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services a) In Eclipse, open the index.html file and locate the property worksetItems inside the shell declaration.At the moment, this property is just an empty array (identified by the empty brackets [ ]) Inside the worksetItems empty brackets, add the following code: Figure 373: Coding This creates a single menu item called Flight Information with three sub-items – Flights, Airports and Bookings. b) After the declaration for the oShell object, add the following code Figure 374: Coding This coding goes immediately before the final statement oShell.placeAt("content"); c) Save index.html and right-click on your WebContent folder.Select Team → Submit.You will now see that the only change to the project is the index.html file.When you press finish, this file will be updated within the SAP NetWeaver server. d) Switch back to your browser and press F5 or Ctrl-R to refresh the screen. Continued on next page 2012 © 2012 SAP AG. All rights reserved. 319 Unit 6: Front-end Application Development e) GW100 You will now see the same shell, but this time with a menu structure and a table for each of the Flight, Airport and Booking entity types. Figure 375: Browser You have now successfully completed a basic SAP UI5 application that is hosted from within an SAP ABAP system. 320 © 2012 SAP AG. All rights reserved. 2012 GW100 Lesson: Consuming Gateway Services Lesson Summary You should now be able to: • The general principles of consuming a Gateway Service. • Creation of OData proxy objects. • Consumption of Gateway Services using Java Server Pages and JavaScript + HTML5. 2012 © 2012 SAP AG. All rights reserved. 321 Unit Summary GW100 Unit Summary You should now be able to: • The general principles of consuming a Gateway Service. • Creation of OData proxy objects. • Consumption of Gateway Services using Java Server Pages and JavaScript + HTML5. 322 © 2012 SAP AG. All rights reserved. 2012 GW100 Course Summary Course Summary You should now be able to: • • • • • 2012 Understand the various development and installation options for SAP NetWeaver Gateway. Explain what functionality SAP NetWeaver Gateway do and does not provide. Understand how to generate a Gateway Service starting from an RFC ABAP Function Module or an Object from the Business Object Repository. Develop from scratch your own Gateway Service in ABAP. Consume a Gateway Service using either a Java application or a JavaScript (browser) based application. © 2012 SAP AG. All rights reserved. 323 Course Summary 324 GW100 © 2012 SAP AG. All rights reserved. 2012 Feedback SAP AG has made every effort in the preparation of this course to ensure the accuracy and completeness of the materials. If you have any corrections or suggestions for improvement, please record them in the appropriate place in the course evaluation. 2012 © 2012 SAP AG. 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GW100 - Building OData Services Using SAP NetWeaver Gateway

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