Object Oriented ABAP Guide

Object Oriented Oriented ABAP P rogramming Nareshkumar Patel SAP-CRM Wipro Technologies

SUMMARY This is a step-by-step guide to learn ABAP Objects. Typically used to enable ABAP developers to place their first step into ABAP Objects. This guide includes examples with ready to use source codes (with output) to explain every topic. PREREQUISITES This guide assumes that the reader has a good knowledge of ABAP Workbench Fundamentals and has hands on experience of creating Report Programs as well as Module Pool Programs. AUTHOR Nareshkumar Patel SAP CRM Technical Consultant Consultant Wipro Technologies CONTENTS • • • • • • • • • • • • • • •

Basic Terminology Classes Objects / Instances Attributes Methods Constructor Object Identity and Reference Semantics Visibility Events Inheritance Polymorphism Interfaces ALV Grid Control ALV Grid Control Using Events ALV Grid Control Using Field Catalogs

BASIC TERMINOLOGY For a long time it was standard practice in software development to subdivide software systems according to the system's functions. Object-orientation takes another approach. Instead of concentrating on functions, the object-oriented approach concentrates on data abstractions using - so-called Classes.

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CLASSES Classes are the central element of object-orientation. A Class describes a general element or a general concept. Classes realize an abstract data type. Classes contain components like: Attributes, Methods and Events. These components are described later in this document. In ABAP Objects classes are made up of a definition and an implementation part. CLASS CL_CLASSNAME DEFINITION. ENDCLASS. CLASS CL_CLASSNAME IMPLEMENTATION. ENDCLASS.

OBJECTS / INSTANCES An object is nothing more than an instance of a Class. Object - A person, place, thing, concept, or event that is applicable to the system at hand. Objects both know things (i.e., they have data) and they do things (i.e. they have functionality). In ABAP Objects, objects are created with the command CREATE OBJECT. The developer receives an object reference as a result of its creation: DATA: instance TYPE REF TO CL_CLASSNAME. START-OF-SELECTION. CREATE OBJECT instance.

ATTRIBUTES Attributes can take on values within an object at runtime. The sum of all attributes and their values describes the state of an object. Attributes can be defined as instance dependent as well as Class dependent. Class attributes (Class attributes are also called static attributes.) are not tied to a single instance, rather they "belong" to all instances of the Class. These attributes exist only once in main memory. Instance-dependent attributes exist once per instance and are tied to a single instance. In ABAP Objects you differentiate between instance-dependent and classdependent attributes by means of the ABAP keywords DATA or CLASS-DATA to be used in the definition part:

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Report : 001 Code listing for: Z_001_SIM Z_001_SIM PL E_CLASS Description: Description: SIMP LE CLASS WITH ATTRIBUTES REPORT Z_001_SIMPLE_CLASS. TYPES: TY_NAME(50) TYPE C. *-----------------------*--------------------------------------------------------------------------------------------------*

CLASS CL_NAME DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_NAME DEFINITION. PUBLIC SECTION. CLASS-DATA I_COUNT TYPE I.

" Class Dependent Attribute

" Will have same value in all objects DATA NAME TYPE TY_NAME.

" Instance Dependent Attribute

" Will have different values in different objects ENDCLASS.

"CL_NAME DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------*

CLASS CL_NAME IMPLEMENTATION

*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_NAME IMPLEMENTATION. " We will use this portion in next examples. ENDCLASS.

"CL_NAME IMPLEMENTATION

" CREATE REFERENCE VARIABLES DATA: INSTANCE1 TYPE REF TO CL_NAME, INSTANCE2 TYPE REF TO CL_NAME, INSTANCE3 TYPE REF TO CL_NAME. START-OF-SELECTION. " CREATE OBJECTS (INSTANCES) CREATE OBJECT: INSTANCE1,

INSTANCE2, INSTANCE3.

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" SET ATTRIBUTES OF INSTANCE1 INSTANCE1->I_COUNT = INSTANCE1->I_COUNT + 10. INSTANCE1->NAME = 'NARESH'. " SET ATTRIBUTES OF INSTANCE2 INSTANCE2->I_COUNT = INSTANCE2->I_COUNT + 10. INSTANCE2->NAME = 'SAMEER'. " SET ATTRIBUTES OF INSTANCE3 INSTANCE3->I_COUNT = INSTANCE3->I_COUNT + 10. INSTANCE3->NAME = 'RAJESH'. " DISPLAY ATTRIBUTES OF INSTANCE1 WRITE: 'ATTRIBUTES OF INSTANCE 1 :::', / 'COUNT : ', INSTANCE1->I_COUNT, / 'NAME : ' , INSTANCE1->NAME. SKIP. SKIP. " DISPLAY ATTRIBUTES OF INSTANCE2 WRITE: 'ATTRIBUTES OF INSTANCE 2 :::', / 'COUNT : ', INSTANCE2->I_COUNT, / 'NAME : ' , INSTANCE2->NAME. SKIP. SKIP. " DISPLAY ATTRIBUTES OF INSTANCE3 WRITE: 'ATTRIBUTES OF INSTANCE 3 :::', / 'COUNT : ', INSTANCE3->I_COUNT, / 'NAME : ' , INSTANCE3->NAME. " CLEAR MEMORY OCCUPIED BY OBJECTS CLEAR: INSTANCE1, INSTANCE2,

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INSTANCE3.

Report Ou tput : 001 ATTRIBUTES OF INSTANCE 1 ::: COUNT :

30

NAME : NARESH ATTRIBUTES OF INSTANCE 2 ::: COUNT :

30

NAME : SAMEER ATTRIBUTES OF INSTANCE 3 ::: COUNT :

30

NAME : RAJESH

METHODS As well as attributes, Classes have so-called Methods. While attributes describe the static structure of a class and its objects, Methods describe the behavior of objects within a class. With the help of methods, the system provides operations, services and functions. Via methods, a user can manipulate the objects in a class or also the class itself. As for attributes, there are instance-dependent as well as classdependent (static) methods. ABAP Objects differentiate between instance-dependent and class-dependent methods via the ABAP keywords METHODS or CLASS-METHODS used in the definition part. In order to carry out instance-dependent (or instance-dependent) methods, the calling program needs a specific instance of the class. That is, the calling program must have a defined reference variable that points to a specific instance. Class methods are not instance-dependent. They can be called at any time by a user. To see how the syntax calls the various method types, see the following example. Report : 002 Code listing for : Z_002_METHODS Description: Description: EXAMP EXAMP LE SHOWI NG USE OF M ETHODS REPORT Z_002_METHODS. TYPES: TY_NAME(50) TYPE C, BOOLEAN(1) TYPE C. CONSTANTS: CO_TRUE TYPE C VALUE 'X',

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CO_FALSE TYPE C VALUE ' '. *-----------------------*--------------------------------------------------------------------------------------------------*


*---------------------------------------------------------------CLASS CL_NAME DEFINITION. PUBLIC SECTION. CLASS-DATA I_COUNT TYPE I.




" Will have different values in different objects CLASS-METHODS IS_CLASS_INITIATED EXPORTING VALUE(RE_BOOL) TYPE BOOLEAN. METHODS: SET_NAME IMPORTING VALUE(IM_NAME) TYPE TY_NAME, GET_NAME EXPORTING VALUE(EX_NAME) TYPE TY_NAME. ENDCLASS.

"CL_NAME DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------*


*---------------------------------------------------------------CLASS CL_NAME IMPLEMENTATION. METHOD IS_CLASS_INITIATED. IF I_COUNT > 0. RE_BOOL = CO_TRUE. ELSE. RE_BOOL = CO_FALSE. ENDIF. ENDMETHOD. "IS_CLASS_INITIATED METHOD SET_NAME. NAME = IM_NAME. ENDMETHOD. "SET_NAME METHOD GET_NAME. EX_NAME = NAME.

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ENDMETHOD. "GET_NAME ENDCLASS.


START-OF-SELECTION. DATA BOOL TYPE BOOLEAN. " CHECK IF ANY INSTANCE OF THIS CLASS HAS BEEN CREATED BEFORE CALL METHOD CL_NAME=>IS_CLASS_INITIATED IMPORTING RE_BOOL = BOOL. IF BOOL = CO_FALSE. " CREATE INSTANCE OF THIS CLASS, IF NO INSTANCE EXIST DATA: INSTANCE TYPE REF TO CL_NAME, NAME TYPE TY_NAME. CREATE OBJECT INSTANCE. " SET VALUE FOR NAME ATTRIBUTE CALL METHOD INSTANCE->SET_NAME EXPORTING IM_NAME = 'NARESH PATEL'. " GET VALUE OF NAME ATTRIBUTE CALL METHOD INSTANCE->GET_NAME IMPORTING EX_NAME = NAME. WRITE: / 'NAME : ' , NAME. " CLEAR MEMORY OCCUPIED BY OBJECTS CLEAR: INSTANCE. ENDIF. Report Ou tput : 002 NAME : NARESH PATEL

CONSTRUCTOR

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Objects must be created at runtime (using CREATE OBJECT). With their creation they also get their own identity. However, there are no fixed attribute values linked to the identity. You are probably already wondering how objects get to their initial state. How do objects recognize their initial attribute values? TheConstructor concept exists specifically to answer this question. The constructor is a method which runs automatically during the creation of an object. The constructor allows you to define IMPORTING-parameters. In ABAP Objects you differentiate between instance-dependent and class-dependent constructors via the language elements METHODS{{ }}and CLASS-METHODS to be used in the definition part and via their namesconstructor and CLASS_CONSTRUCTOR: The class constructor is called by the first access to a class element (method, attribute, event, and object), the (instance) constructor by the creation of an object (CREATE OBJECT). Report : 003 Code listing for: Z_003_CONSTRUCTOR Z_003_CONSTRUCTOR Description : EXAM PL E OF USING CONSTRUCTOR CONSTRUCTOR REPORT Z_003_CONSTRUCTOR. TYPES: TY_NAME(50) TYPE C. *-----------------------*--------------------------------------------------------------------------------------------------*


*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_NAME DEFINITION. PUBLIC SECTION. CLASS-DATA I_COUNT TYPE I.




" Will have different values in different objects CLASS-METHODS CLASS_CONSTRUCTOR. METHODS: CONSTRUCTOR IMPORTING VALUE(IM_NAME) TYPE TY_NAME, GET_NAME EXPORTING VALUE(EX_NAME) TYPE TY_NAME. ENDCLASS.

"CL_NAME DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------*


*---------------------------------------------------------------CLASS CL_NAME IMPLEMENTATION.

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METHOD CLASS_CONSTRUCTOR. I_COUNT = I_COUNT + 10. ENDMETHOD. "IS_CLASS_INITIATED METHOD CONSTRUCTOR. NAME = IM_NAME. ENDMETHOD. "SET_NAME METHOD GET_NAME. EX_NAME = NAME. ENDMETHOD. "GET_NAME ENDCLASS.


START-OF-SELECTION. " CREATE INSTANCE OF THIS CLASS, IF NO INSTANCE EXISTS. DATA: INSTANCE1 TYPE REF TO CL_NAME, INSTANCE2 TYPE REF TO CL_NAME, NAME1 TYPE TY_NAME, NAME2 TYPE TY_NAME. CREATE OBJECT INSTANCE1 EXPORTING IM_NAME = 'NARESH PATEL'. CREATE OBJECT INSTANCE2 EXPORTING IM_NAME = 'SAMEER V. PATEL'. " GET VALUE OF NAME ATTRIBUTE CALL METHOD INSTANCE1->GET_NAME IMPORTING EX_NAME = NAME1. CALL METHOD INSTANCE2->GET_NAME IMPORTING EX_NAME = NAME2.

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" DISPLAY ATTRIBUTES OF INSTANCE1 WRITE: 'ATTRIBUTES OF INSTANCE 1 : ', / 'COUNT : ', INSTANCE1->I_COUNT, / 'NAME : ' , NAME1. SKIP. SKIP. " DISPLAY ATTRIBUTES OF INSTANCE2 WRITE: 'ATTRIBUTES OF INSTANCE 2 : ', / 'COUNT : ', INSTANCE2->I_COUNT, / 'NAME : ' , NAME2. " CLEAR MEMORY OCCUPIED BY OBJECTS CLEAR: INSTANCE1, INSTANCE2. Report Ou tput : 003 ATTRIBUTES ATTRIBUTES OF INSTANCE 1 : COUNT :

10

NAME : NARESH PATEL ATTRIBUTES OF INSTANCE 2 : COUNT :

10

NAME : SAMEER V. PATEL

OBJECT IDENTITY AND REFERENCE SEMANTI SEMANTI CS With the help of the previous examples, you have established that objects belonging to a class are not created by the simple definition of the class. Neither does the instruction DATA: instance ref to CL_NAME creates an object. This instruction only creates a Reference, which in its initial state has the logical value INITIAL. Only with the instruction CREATE OBJECTinstance is the memory area for a new object requested from the system. The reference instance then refers to the object which has just been created. (The command CLEAR{{ instance. }}at this point means that the object, to which the reference variable refers, cannot be referenced. Therefore it can no longer be addressed in this program run. A Garbage Collector running in the background ensures that the object is removed from memory.

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This separates object-oriented implementation from classic implementation. With the classic DATA instruction, main memory is reserved (which might never be used) and is pre-allocated the initial state of the relevant variable. With the "objectoriented" instruction DATA-x-TYPE-REF-TO, only the intention to create an object is expressed. The only storage space occupied is for an object reference. In addition, every object has its own identity. Two references, which refer to objects, are only identical if they refer to the same object. Similarity between the attribute values of these objects is not the deciding factor. To get more idea about this see the following example. Report : 004 Code listing for: Z_004_OBJECT_IDENTI TY Description: Description: OBJECT IDENTITY & REFERENCE REFERENCE SEMANTICS REPORT Z_004_OBJECT_IDENTITY. TYPES: TY_NAME(50) TYPE C. *-----------------------*--------------------------------------------------------------------------------------------------*


*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_NAME DEFINITION. PUBLIC SECTION. METHODS: CONSTRUCTOR IMPORTING VALUE(IM_NAME) TYPE TY_NAME. DATA: NAME TYPE TY_NAME. ENDCLASS.

"CL_NAME DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------*


*---------------------------------------------------------------CLASS CL_NAME IMPLEMENTATION. METHOD CONSTRUCTOR. NAME = IM_NAME. ENDMETHOD. ENDCLASS.

"CONSTRUCTOR "CL_NAME IMPLEMENTATION

DATA: INSTANCE1 TYPE REF TO CL_NAME. DATA: INSTANCE2 TYPE REF TO CL_NAME. DATA: INSTANCE3 TYPE REF TO CL_NAME.

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START-OF-SELECTION. CREATE OBJECT INSTANCE1 EXPORTING IM_NAME = 'NARESH'. CREATE OBJECT INSTANCE2 EXPORTING IM_NAME = 'NARESH'. " Reference semantics !!! IF INSTANCE1 = INSTANCE2. WRITE 'This will never print, as instance1 refers to a different object than instance2.'. ENDIF. " Attribute values are the same !!! IF INSTANCE1->NAME = INSTANCE2->NAME. WRITE 'Attribute values of instance1 and instace2 are same.'. ENDIF. INSTANCE3 = INSTANCE1. IF INSTANCE3 = INSTANCE1. WRITE 'Both references instance1 and instace3 refer to the same object and are therefore identical.'. ENDIF. Report Ou tput : 004 Attribute values of instance1 and instace2 are same. Both references instance1 and instace3 refer to the same object and are therefore identical. In the above program, the first IF-Query (IF }}INSTANCE1 = INSTANCE2{{.) via the object reference produces the value false, although both objects have the same attribute value "NARESH". Note that in object-oriented languages the reference semantics apply for classes and their objects. Both objects have the attribute value {{NAME = }}NARESH, but they are independent objects with their own identity. The references therefore refer to two different objects, although their attribute values are completely identical.

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VISIBILITY An important feature of object-orientation is the encapsulation of attributes and methods - ultimately of functionality - in classes. A class guarantees its user specific properties and specific behavior. The sum of these properties is called the class interface. The Visibility mechanism defines the class interface which is available to the users. There are three commonly defined types of visibility in object-oriented technology: Public

The relevant class component (attribute, method, event etc.) is visible to all classes. Protected

The relevant class component (attribute, method, event etc.) is visible to the class itself and all inheritors. (We will return to the terms Inheritor and Inheritance later in this document.) Private

The relevant class component (attribute, method, event etc.) is only visible to the class itself. Report : 005 Code listing for: Z_005_VISIBILITY Description: Description: COMPONENT COMPONENT VISIBI LITY *-----------------------*------------------------------------------------------------------------------------------------* In this example the PRIVATE attribute NAME is hidden from the * users. Access to the information it contains is realized via * the PUBLIC method SET_NAME & GET_NAME. *-----------------------*------------------------------------------------------------------------------------------------* * TYPES OF VISIBILITY : * (1) PUBLIC : class component is visible to all classes. * (2) PRIVATE : class component is visible to the class itself. * (3) PROTECTED : class component is visible to class itself and *

all inheritors (sub class).

* *-----------------------*------------------------------------------------------------------------------------------------REPORT Z_005_VISIBILITY. TYPES: TY_NAME(50) TYPE C. *---------------------------------------------------------------*


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*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_NAME DEFINITION. PUBLIC SECTION. METHODS: SET_NAME IMPORTING VALUE(IM_NAME) TYPE TY_NAME, GET_NAME EXPORTING VALUE(EX_NAME) TYPE TY_NAME. PRIVATE SECTION. DATA NAME TYPE TY_NAME. ENDCLASS.

"CL_NAME DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------*


*-----------------------*---------------------------------------------------------------------------------------------------CLASS CL_NAME IMPLEMENTATION. METHOD SET_NAME . NAME = IM_NAME. ENDMETHOD. "SET_NAME METHOD GET_NAME. EX_NAME = NAME. ENDMETHOD. "GET_NAME ENDCLASS.


START-OF-SELECTION. " CREATE INSTANCE OF THIS CLASS, IF NO INSTANCE EXIST DATA: INSTANCE TYPE REF TO CL_NAME, NAME TYPE TY_NAME. CREATE OBJECT INSTANCE. " SET VALUE FOR NAME ATTRIBUTE CALL METHOD INSTANCE->SET_NAME EXPORTING IM_NAME = 'NARESH PATEL'. " GET VALUE OF NAME ATTRIBUTE CALL METHOD INSTANCE->GET_NAME IMPORTING

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EX_NAME = NAME. WRITE: / 'NAME : ' , NAME. " CLEAR MEMORY OCCUPIED BY OBJECTS CLEAR: INSTANCE. Report Ou tput : 005 NAME : NARESH PATEL

EVENTS Events are recognized in particular by programming interfaces of the GUIs (Windows, Motif, etc.), for example, you can "ask" the GUI to trigger an event if the user moves the mouse over a specific part of the screen. When the event occurs you are telling the GUI to change the shape of the mouse pointer. Events allow for the loose coupling of components (classes or objects) in a system. The event trigger does not normally know at the time of coding who is going to react to the event. Those components, which want to react to the event, register at the event runtime, in that they tell the runtime environment which method is to be executed when the event is raised. In this way many components can register for an event. Event handler methods can proceed synchronously as well as asynchronously. At present, ABAP Objects only supports synchronous calling of the event handler method. Report : 006 Code listing fo r: Z_006_EVENT Description: Description: EXAMPLE OF EVENTS *--------------------------------------------------------------* THIS EXAMPLE SHOWS THE USE OF EVENTS. *-----------------------*------------------------------------------------------------------------------------------------* * The event trigger does not normally know at the time of * coding who is going to react to the event. Those components, * which want to react to the event, register at the event * runtime, in that they tell the runtime environment which * method is to be executed when the event is raised. In this way * many components can register for an event. * *---------------------------------------------------------------

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REPORT Z_006_EVENT. *-----------------------*--------------------------------------------------------------------------------------------------*

CLASS CL_NAME

*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_NAME DEFINITION. PUBLIC SECTION. " DEFINE EVENT EVENTS OBJECT_CREATED OBJECT_CREATED EXPORTING VALUE(EX_OBJ) TYPE REF TO CL_NAME. METHODS: CONSTRUCTOR, " DEFINE EVENT HANDLER METHOD PROCESS_EVENT FOR EVENT OBJECT_CREATED OF CL_NAME. PRIVATE SECTION. DATA MSG(16) TYPE C. " register method with runtime will be executed " when event OBJECT_CREATED fires. ENDCLASS.

"CL_NAME

*-----------------------*--------------------------------------------------------------------------------------------------*


*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_NAME IMPLEMENTATION. METHOD CONSTRUCTOR. MSG = 'OBJECT CREATED'. " Register the event handlers for the corresponding/all " instance/s. SET HANDLER PROCESS_EVENT FOR ALL INSTANCES. " Raise event OBJECT_CREATED. RAISE EVENT OBJECT_CREATED EXPORTING EX_OBJ = ME. "ME refers to current instance ENDMETHOD.

"CL_NAME

" EVENT HANDLER METHOD PROCESS_EVENT.

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WRITE: 'EVENT FIRED :', ME->MSG. ENDMETHOD. ENDCLASS.

"PROCESS_EVENT "CL_NAME IMPLEMENTATION

DATA INSTANCE TYPE REF TO CL_NAME. START-OF-SELECTION. CREATE OBJECT INSTANCE. CLEAR INSTANCE. Report Ou tput : 006 EVENT FIRED : OBJECT CREATED In the previous program, instances of the Class CL_NAMEcreate an event OBJECT_CREATED. OBJECT_CREATE D. The The class method PROCESS_EVEN PROCESS_EVENT T processes this event. With the help of the constructor the class registers the method PROCESS_EVENT at the event OBJECT_CREATED for all instances of the class CL_NAME. When an object is created for the class CL_NAME (CREATE OBJECT instance.), the event OBJECT_CREATED is raised in the constructor. The consequence is that the method PROCESS_EVENT{{ }}is executed. Report : 007 Code listing for : Z_007_EVENT2 Description: EVENT EVENT OF ONE CLASS HANDLED BY AN OTHER CLASS REPORT Z_007_EVENT2. *-----------------------*--------------------------------------------------------------------------------------------------*

CLASS CL_CLASS1 DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_CLASS1 DEFINITION. PUBLIC SECTION. EVENTS OBJECT_CREATED. OBJECT_CREATED. " DEFINES EVENT METHODS CONSTRUCTOR. ENDCLASS.

"CL_CLASS1 DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------*

CLASS CL_CLASS1 IMPLEMENTATION

*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_CLASS1 IMPLEMENTATION.

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METHOD CONSTRUCTOR. RAISE EVENT OBJECT_CREATED. " RAISES EVENT ENDMETHOD. ENDCLASS.

"CONSTRUCTOR "CL_CLASS1 IMPLEMENTATION

*-----------------------*--------------------------------------------------------------------------------------------------*


*---------------------------------------------------------------CLASS CL_CLASS2 DEFINITION. PUBLIC SECTION. CLASS-METHODS INITIALISE. PRIVATE SECTION. CLASS-METHODS PROCESS_EVENT FOR EVENT OBJECT_CREATED OF CL_CLASS1. " REGISTERS METHOD ENDCLASS.


*-----------------------*--------------------------------------------------------------------------------------------------*


*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_CLASS2 IMPLEMENTATION. METHOD INITIALISE. "SET HANDLER FOR ALL INSTANCES SET HANDLER PROCESS_EVENT FOR ALL INSTANCES. ENDMETHOD.

"INITIALISE

" EVENT HANDLER METHOD PROCESS_EVENT. WRITE 'EVENT FIRED.'. ENDMETHOD. ENDCLASS.

"PROCESS_EVENT "CL_CLASS2 IMPLEMENTATION

DATA INSTANCES TYPE REF TO CL_CLASS1. START-OF-SELECTION. CALL METHOD CL_CLASS2=>INITIALISE. CREATE OBJECT INSTANCES.

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CLEAR INSTANCES. Report Ou tput : 007 EVENT FIRED. In the above program, with the help of the class method initialize, the class CL_CLASS2 registers the method PROCESS_EVENT at the event OBJECT_CREATED for all instances of the class CL_CLASS1. When an object is created for the class CL_CLASS1 (CREATE OBJECT instance.), the event OBJECT_CREATED is raised in the constructor. The consequence is that the method PROCESS_EVENT{{ }}belonging to the class CL_CLASS2 is executed.

INHERITANCE Inheritance defines the relationship between classes, in which a class (subclass) uses the structure and behavior that has already been defined in one or more other classes (superclasses). So simply this means "Inheritance is about reuse!". Allow me to use a concrete example to explain inheritance: Collection. A collection is any number of objects (more precisely object references). However, there could be many types of collection. Therefore, I will implement each type of collection as a class. In principle this approach is correct. However, you will soon establish that all collections have several components in common like: 1.

Each class requires a method in order to add objects to a collection.

2. collection.

Each class requires a method in order to delete objects from a

3. Each class has a method which identifies the number of object references in the collection and so on. Inheritance is the solution to this situation. You implement all of the similarities in the class which is Superclass. You then implement the individual types of collection in their own classes which are Subclassesof the Superclass. As a subclass, these classes inherit all of the components of the Superclass. Attributes, methods and events are inherited. In addition, you can implement additional attributes, methods and events in the subclass.

POLYMORPHISM Polymorphism occurs, where classes implement the same functionality with different methods (one functionality, several methods but the same name). This can occur via an inheritance relationship, in that the methods belonging to the superclass are redefined in the subclasses and implemented differently. ABAP Objects requires the method names to be the same and the signature to be the same (signature = method interface). Polymorphism can be achieved in 2 ways:

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(1) Two independent classes implement methods with the same names and the same signature with the intention, that the methods should be called dynamically from a third location. (2) A superclass implements a method, and in a subclass you want to re-implement the same method, as the superclass implementation is not suitable for the subclass. The first scenario will not occur very often in ABAP Objects, as the interface concept was created precisely for such cases. Report : 008 Code listing for: Z_008_INHERIT Z_008_INHERIT _POLY Description: Description: EXAMPL E OF INHERITANCE & POLYM ORPI SM REPORT Z_008_INHERIT_POLY. TYPES: BEGIN OF TY_NAME, NAME(50) TYPE C, END OF TY_NAME. TYPES: TY_NAMES TYPE TY_NAME OCCURS 0. *-----------------------*--------------------------------------------------------------------------------------------------*

CLASS CL_COLLECTION DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_COLLECTION DEFINITION. PUBLIC SECTION. METHODS: ADD IMPORTING IM_NAME TYPE TY_NAME, DISPLAY. PROTECTED SECTION. DATA IT_NAMES TYPE TY_NAMES. ENDCLASS.

"CL_COLLECTION DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------*

CLASS CL_COLLECTION IMPLEMENTATION

*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_COLLECTION IMPLEMENTATION. METHOD ADD. APPEND IM_NAME TO IT_NAMES. ENDMETHOD.

"ADD

METHOD DISPLAY.

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DATA: CNT TYPE I. DESCRIBE TABLE IT_NAMES LINES CNT. IF CNT > 0. DATA WA_NAME LIKE LINE OF IT_NAMES. ULINE. WRITE 10 'DISPLAYING DATA'. ULINE. WRITE 10 'NAMES'. ULINE. LOOP AT IT_NAMES INTO WA_NAME. WRITE /10 WA_NAME-NAME. ENDLOOP. ENDIF. ENDMETHOD. ENDCLASS.

"DISPLAY "CL_COLLECTION IMPLEMENTATION

*-----------------------*--------------------------------------------------------------------------------------------------*


*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_NAME DEFINITION INHERITING FROM CL_COLLECTION. PUBLIC SECTION. METHODS: ADD REDEFINITION. " THIS IS CALLED POLYMORPISM. ENDCLASS.

"CL_NAME DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------*


*---------------------------------------------------------------CLASS CL_NAME IMPLEMENTATION. METHOD ADD. " NO DOUBLE ENTRIES ARE ALLOWED. READ TABLE IT_NAMES WITH KEY NAME = IM_NAME-NAME TRANSPORTING NO FIELDS. IF SY-SUBRC <> 0. CALL METHOD SUPER->ADD EXPORTING

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IM_NAME = IM_NAME. ENDIF. ENDMETHOD. ENDCLASS.

"ADD "CL_NAME IMPLEMENTATION

DATA: INSTANCE TYPE REF TO CL_NAME, ST_NAME TYPE TY_NAME. START-OF-SELECTION. CREATE OBJECT INSTANCE. ST_NAME-NAME = 'NARESH PATEL'. CALL METHOD INSTANCE->ADD EXPORTING IM_NAME = ST_NAME. WRITE / 'ADDED NARESH PATEL FOR THE 1ST TIME.'. ST_NAME-NAME = 'SAMEER PATEL'. CALL METHOD INSTANCE->ADD EXPORTING IM_NAME = ST_NAME. WRITE / 'ADDED SAMEER PATEL FOR THE 1ST TIME.'. ST_NAME-NAME = 'RAJESH PATEL'. CALL METHOD INSTANCE->ADD EXPORTING IM_NAME = ST_NAME. WRITE / 'ADDED RAJESH PATEL FOR THE 1ST TIME.'. ST_NAME-NAME = 'NARESH PATEL'. CALL METHOD INSTANCE->ADD EXPORTING IM_NAME = ST_NAME. WRITE / 'ADDED NARESH PATEL FOR THE 2ND TIME.'. ST_NAME-NAME = 'SAMEER PATEL'.

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CALL METHOD INSTANCE->ADD EXPORTING IM_NAME = ST_NAME. WRITE / 'ADDED SAMEER PATEL FOR THE 2ND TIME.'. ST_NAME-NAME = 'RAJESH PATEL'. CALL METHOD INSTANCE->ADD EXPORTING IM_NAME = ST_NAME. WRITE / 'ADDED RAJESH PATEL FOR THE 2ND TIME.'. SKIP. SKIP. CALL METHOD INSTANCE->DISPLAY. Report Ou tput : 008 ADDED NARESH PATEL FOR THE 1ST TIME. ADDED SAMEER PATEL FOR THE 1ST TIME. ADDED RAJESH PATEL FOR THE 1ST TIME. ADDED NARESH PATEL FOR THE 2ND TIME. ADDED SAMEER PATEL FOR THE 2ND TIME. ADDED RAJESH PATEL FOR THE 2ND TIME. ----------------------------------------------------------------------------------------------------------------------------DISPLAYING DATA ----------------------------------------------------------------------------------------------------------------------------NAMES ----------------------------------------------------------------------------------------------------------------------------NARESH PATEL SAMEER PATEL RAJESH PATEL In the above example, I have partially implemented the class CL_COLLECTION and its inheritor class CL_NAME. The method ADD{{ }}belonging to the class CL_COLLECTION is redefined by the method ADD{{ }}belonging to the class CL_NAME. In the method ADDbelonging to the CL_NAME the method ADD belonging to the superclass CL_COLLECTION is called via CALL METHOD SUPER-

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>ADD.

INTERFACES TheInterface concept describes a class interface. You can define the same components in an interface that you can in classes, however without implementing them. Classes can implement interfaces, and subsequently be addressed via these interfaces. This opens an additional mechanism of polymorphism, however without being dependent on inheritance. This combination of classes with simple inheritance and interfaces is more highly regarded by many experts than full multiple inheritances. In addition to object references (DATA: instance TYPE REF TO CL_CLASS) there are also Interface References (DATA: reference TYPE REF TO CL_INTERFACE). A class which implements a specific interface can be addressed via this interface reference. Using such an interface reference, you can access the components defined in the interface. In this way a user can view different classes through the 'spectacles' of an interface and address them in a uniform manner. Interfaces therefore define specific, generic functionality. In contrast to classes, interfaces generally have not only many users, but also many implementers. Report : 009 Code listing for: Z_009_INT ERFACE Description: Description: EXAMP EXAMP LE OF I NTERFACE *-----------------------*------------------------------------------------------------------------------------------------* Report Z_009_INTERFACE *-----------------------*------------------------------------------------------------------------------------------------* * The Interface concept describes a class interface. You can * define the same components in an interface that you can in * classes, however without implementing them. Classes can * Implement interfaces, and subsequently be addressed via these * interfaces. * *-----------------------*------------------------------------------------------------------------------------------------* IN THIS EXAMPLE : The Interface IF_INTERFACE is implemented * via the classes CL_CLASS1 And CL_CLASS2. *-----------------------*------------------------------------------------------------------------------------------------REPORT Z_009_INTERFACE.

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*-----------------------*--------------------------------------------------------------------------------------------------*

INTERFACE IF_INTERFACE

*-----------------------*--------------------------------------------------------------------------------------------------INTERFACE IF_INTERFACE. METHODS DISPLAY. ENDINTERFACE.

"IF_INTERFACE

*-----------------------*--------------------------------------------------------------------------------------------------*


*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_CLASS1 DEFINITION. PUBLIC SECTION. INTERFACES IF_INTERFACE. ENDCLASS.


*---------------------------------------------------------------*


*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_CLASS1 IMPLEMENTATION. METHOD IF_INTERFACE~DISPLAY. WRITE / 'METHOD IMPLEMENTED IN CLASS 1.'. ENDMETHOD. ENDCLASS.

"IF_INTERFACE~DISPLAY "CL_CLASS1 IMPLEMENTATION

*-----------------------*--------------------------------------------------------------------------------------------------*


*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_CLASS2 DEFINITION. PUBLIC SECTION. INTERFACES IF_INTERFACE. ENDCLASS.


*-----------------------*--------------------------------------------------------------------------------------------------*


*----------------------------------------------------------------

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CLASS CL_CLASS2 IMPLEMENTATION. METHOD IF_INTERFACE~DISPLAY. WRITE / 'METHOD IMPLEMENTED IN CLASS 2.' . ENDMETHOD. ENDCLASS.

"IF_INTERFACE~DISPLAY "CL_CLASS2 IMPLEMENTATION

DATA: INSTANCE1 TYPE REF TO CL_CLASS1, INSTANCE2 TYPE REF TO CL_CLASS2, INTERFACE TYPE REF TO IF_INTERFACE. START-OF-SELECTION. CREATE OBJECT INSTANCE1. INTERFACE = INSTANCE1. " THIS ASSIGNATIN IS CALLED CASTING CALL METHOD INTERFACE->DISPLAY. CREATE OBJECT INSTANCE2. INTERFACE = INSTANCE2. CALL METHOD INTERFACE->DISPLAY. Report Ou tput : 009 METHOD IMPLEMENTED IN CLASS 1. METHOD IMPLEMENTED IN CLASS 2.

ALV GRID CONTROL The ALV Grid Control is a tool that you can use to display non-hierarchical lists in a uniform format. The list data is displayed as a table on the screen. This tool is very user-friendly: You only have to carry out a minimum number of programming steps. The ALV Grid Control has a number of interactive standard functions that list users frequently use, for example, printing, and export. Developers can hide these standard functions if they wish. However, you can modify the implementations on an application-specific basis if required. You can also add your own functions to the application toolbar. Application controls like ALV Grid Control, Tree Controls, and Picture Controls must be embedded in a Container Control, which in turn must be connected with the screen. Container Controls form the technical connection between a screen and an application control. There are different types of container controls. All of these types encapsulate basic control functions (for example, scroll bars).

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In the following sections, we will work trough a standard case as an example: Positioning an ALV Grid Control in a screen area with a fixed size. To do this, an instance of each of the global classes CL_GUI_CUSTOM_CONTAINER and CL_GUI_ALV_GRID must be generated. For a basic standard display, it is enough to program the following steps: 1. Define a custom control area on your screen using the screen painter's graphical full screen editor. 2. Generate an instance of the CL_GUI_CUSTOM_CONTAINER class and give the constructor the name of the custom control area you have defined. 3. Generate an instance of the class CL_GUI_ALV_GRID and assign the constructor the reference to the container control instance you have just generated. 4. Call the SET_TABLE_FOR_FIRST_DISPLAY method of the Grid Control instance and assign it the internal standard table and application data. If this method has a global line type, you can give it the name of this global structure. The field catalog will then be set up by the grid control instance itself. If the contents of the internal table change during the rest of the program run, it is enough to call the method REFRESH_TABLE_DISPLAY in the corresponding dialog step, to update the display accordingly. Report : 010 Code listing for: Z_010_ALV_GRI D_CONTROL Description: Description: EXAMP EXAMP LE OF A LV GRID CONTROL CONTROL *-----------------------*---------------------------------------------------------------------------------------------------*

SCREEN 101 : FLOW LOGIC

*-----------------------*--------------------------------------------------------------------------------------------------PROCESS BEFORE OUTPUT. MODULE STATUS_0101. MODULE GET_DATA. MODULE CREATE_OBJECTS. MODULE SHOW_ALV. PROCESS AFTER INPUT. MODULE USER_COMMAND_0101. *---------------------------------------------------------------*

MODULE POOL

Z_010_ALV_GRID_CONTROL Z_010_ ALV_GRID_CONTROL

*-----------------------*--------------------------------------------------------------------------------------------------INCLUDE Z_010_ALV_GRID_CONTROL_TOP. " Global Data INCLUDE Z_010_ALV_GRID_CONTROL_O01. " PBO-Modules INCLUDE Z_010_ALV_GRID_CONTROL_I01. " PAI-Modules

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INCLUDE Z_010_ALV_GRID_CONTROL_F01. " FORM-Routines *-----------------------*-------------------------------------------------------------------------------------------------------------------------------------*

TOP INCLUDE

Z_010_ALV_GRID_CONTROL_TOP Z_010_ ALV_GRID_CONTROL_TOP

*----------------------------------------------------------------------------------REPORT Z_010_ALV_GRID_CONTROL. TABLES: SFLIGHT. DATA: OK_CODE TYPE SY-UCOMM, IT_SFLIGHT TYPE STANDARD TABLE OF SFLIGHT, R_CONTAINER TYPE REF TO CL_GUI_CUSTOM_CONTAINER, R_GRID TYPE REF TO CL_GUI_ALV_GRID. *-----------------------*-------------------------------------------------------------------------------------------------------------------------------*

PBO INCLUDE

Z_010_ALV_GRID_CONTROL_O Z_010_ALV_G RID_CONTROL_O01 01

*-------------------------------------------------------------------------------*-----------------------*--------------------------------------------------------------------------------------------------*

Module

SHOW_ALV OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE SHOW_ALV OUTPUT. CHECK OK_CODE IS INITIAL. CALL METHOD R_GRID->SET_TABLE_FOR_FIRST_DISPLAY EXPORTING I_STRUCTURE_NAME = 'SFLIGHT' CHANGING IT_OUTTAB

= IT_SFLIGHT.

ENDMODULE.

" SHOW_ALV OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------*

Module

GET_DATA OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE GET_DATA OUTPUT. CHECK OK_CODE IS INITIAL. PERFORM GET_DATA USING SFLIGHT-CARRID.

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ENDMODULE.

" GET_DATA OUTPUT

*------------------------*--------------------------------------------------------------------------------------------------*

Module

CREATE_OBJECTS OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE CREATE_OBJECTS OUTPUT. CHECK OK_CODE IS INITIAL. CREATE OBJECT R_CONTAINER EXPORTING CONTAINER_NAME = 'CC_ALV'. CREATE OBJECT R_GRID EXPORTING I_PARENT = R_CONTAINER. ENDMODULE.

" CREATE_OBJECTS OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------*

Module

STATUS_0101 OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE STATUS_0101 OUTPUT. SET PF-STATUS 'Z_010_STATUS'. "SET TITLEBAR 'xxx'. ENDMODULE.

" STATUS_0101 OUTPUT

*-----------------------*-------------------------------------------------------------------------------------------------------------------------*

PA I INCLUDE

Z_010_ALV_GRID_CONTROL_I01 Z_010_ ALV_GRID_CONTROL_I01

*-----------------------*-------------------------------------------------------------------------------------------------------------------------*-----------------------*--------------------------------------------------------------------------------------------------*

Module

USER_COMMAND_0101 INPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE USER_COMMAND_0101 INPUT. CASE OK_CODE . WHEN 'SEARCH'. PERFORM GET_DATA USING SFLIGHT-CARRID.

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CALL METHOD R_GRID->REFRESH_TABLE_DISPLAY. WHEN 'EXIT'. LEAVE PROGRAM. ENDCASE. ENDMODULE.

" USER_COMMAND_0101 INPUT

*-----------------------*---------------------------------------------------------------------------------------------------------------------------------------*

FORM INCLUDE

Z_010_ALV_GRID_CONTROL_F01 Z_010_ALV_G RID_CONTROL_F01

*-----------------------*---------------------------------------------------------------------------------------------------------------------------------------*-----------------------*--------------------------------------------------------------------------------------------------* FORM

: GET_DATA

* Created : 26.03.2008 12:34:09 *---------------------------------------------------------------FORM GET_DATA USING VALUE(P_CARRID) TYPE SFLIGHT-CARRID. IF P_CARRID IS INITIAL. SELECT * FROM SFLIGHT INTO CORRESPONDING FIELDS OF TABLE T_SFLIGHT. ELSE. SELECT * FROM SFLIGHT INTO CORRESPONDING FIELDS OF TABLE IT_SFLIGHT WHERE CARRID = P_CARRID. ENDIF. ENDFORM. "GET_DATA ALV GRI D CONTROL USING EVENTS An ALV Grid Control can react to a user double-clicking the mouse button. One possible reaction is that a subsequent processing is triggered in which additional information is displayed. The event DOUBLE_CLICK is caught using a handler method. A handler method can be either a class method (static method) or an object's instance method. If a class method is defined as a handler method, there is no need to instantiate an object of the handling class, to use the method. To create a handler object for an event, you must first of all define a class. This class has a public method (in the PUBLIC SECTION) that can react to an event. In the handler method's implementation, create the source text that will run when you trigger the event. The method receives the information delivered by the event from the position of the mouse when the user executes a double-click, and in the control example, generates an information message that displays the line and field where the mouse is clicked.

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Report : 011 Code listing for: Z_011_ALV_GRI D_EVENT Description: Description: EXAMP EXAMP LE OF A LV GRID CONTROL CONTROL *-----------------------*--------------------------------------------------------------------------------------------------*

SCREEN 101 : FLOW LOGIC

*-----------------------*--------------------------------------------------------------------------------------------------PROCESS BEFORE OUTPUT. MODULE STATUS_0101. MODULE GET_DATA. MODULE CREATE_OBJECTS. MODULE SHOW_ALV.

PROCESS AFTER INPUT. MODULE USER_COMMAND_0101. *---------------------------------------------------------------*

MODULE POOL

Z_011_ALV_GRID_EVENT Z_01 1_ALV_GRID_EVENT

*---------------------------------------------------------------REPORT Z_011_ALV_GRID_EVENT. *-----------------------*--------------------------------------------------------------------------------------------------*

CLASS CL_EVENT_HANDLER DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_EVENT_HANDLER DEFINITION. PUBLIC SECTION. METHODS: ON_DOUBLE_CLICK FOR EVENT DOUBLE_CLICK OF CL_GUI_ALV_GRID IMPORTING ES_ROW_NO E_COLUMN, ON_RIGHT_CLICK FOR EVENT RIGHT_CLICK OF CL_GUI_ALV_GRID. ENDCLASS.

"CL_EVENT_HANDLER DEFINITION

*-----------------------*--------------------------------------------------------------------------------------------------*

CLASS CL_EVENT_HANDLER IMPLEMENTATION

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*-----------------------*--------------------------------------------------------------------------------------------------CLASS CL_EVENT_HANDLER IMPLEMENTATION. METHOD ON_DOUBLE_CLICK. DATA: TEXT TYPE STRING, ES_ROW_STRING TYPE STRING. ES_ROW_STRING = ES_ROW_NO-ROW_ID. CONCATENATE 'ROW : ' ES_ROW_STRING 'COLUMN : ' E_COLUMN-FIELDNAME INTO TEXT SEPARATED BY SPACE. MESSAGE MESSAGE TEXT TYPE 'I'. ENDMETHOD.

"ON_DOUBLE_CLICK

METHOD ON_RIGHT_CLICK. MESSAGE 'RIGHT MOUSE BUTTON HAS CLICKED !!!' TYPE 'I'. ENDMETHOD. ENDCLASS.

"ON_RIGHT_CLICK "CL_EVENT_HANDLER IMPLEMENTATION

*-----------------------*--------------------------------------------------------------------------------------------------*

INCLUDE PROGRAMS

*-----------------------*--------------------------------------------------------------------------------------------------INCLUDE Z_011_ALV_GRID_EVENT_TOP. " Global Data INCLUDE Z_011_ALV_GRID_EVENT_O01. " PBO-Modules INCLUDE Z_011_ALV_GRID_EVENT_I01. " PAI-Modules INCLUDE Z_011_ALV_GRID_EVENT_F01. " FORM-Routines *-----------------------*---------------------------------------------------------------------------------------------------* TOP INCLUDE Z_011_ALV_GRID_EVENT_TOP *-----------------------*---------------------------------------------------------------------------------------------------*-----------------------*---------------------------------------------------------------------------------------------------* TYPES AND DATA DECLARATION *-----------------------*---------------------------------------------------------------------------------------------------TABLES: SFLIGHT. DATA: OK_CODE TYPE SY-UCOMM, IT_SFLIGHT TYPE STANDARD TABLE OF SFLIGHT, R_HANDLER TYPE REF TO CL_EVENT_HANDLER, R_CONTAINER TYPE REF TO CL_GUI_CUSTOM_CONTAINER,

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R_GRID TYPE REF TO CL_GUI_ALV_GRID. *-----------------------*-------------------------------------------------------------------------------------------------------------------*

PBO INCLUDE

Z_011_ALV_GRID_EVENT_O01 Z_011_ALV_G RID_EVENT_O01

*-----------------------*------------------------------------------------------------------------------------------------------------------*-----------------------*------------------------------------------------------------------------------------------------*

Module

SHOW_ALV OUTPUT

*--------------------------------------------------------------MODULE SHOW_ALV OUTPUT. CHECK OK_CODE IS INITIAL. CALL METHOD R_GRID->SET_TABLE_FOR_FIRST_DISPLAY EXPORTING I_STRUCTURE_NAME = 'SFLIGHT' CHANGING IT_OUTTAB ENDMODULE.

= IT_SFLIGHT. " SHOW_ALV OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------*

Module

GET_DATA OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE GET_DATA OUTPUT. CHECK OK_CODE IS INITIAL. PERFORM GET_DATA USING SFLIGHT-CARRID. ENDMODULE.

" GET_DATA OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------*

Module


*-----------------------*--------------------------------------------------------------------------------------------------MODULE CREATE_OBJECTS OUTPUT. IF R_HANDLER IS NOT BOUND.

"CHECKS WHETHER A REFERENCE

"VARIABLE CONTAINS VALID REFERENCE CREATE OBJECT R_HANDLER. ENDIF.

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IF R_CONTAINER IS NOT BOUND.

"CHECKS WHETHER A REFERENCE

"VARIABLE CONTAINS VALID REFERENCE CREATE OBJECT R_CONTAINER EXPORTING CONTAINER_NAME = 'CC_ALV'. ENDIF. IF R_GRID IS NOT BOUND. CREATE OBJECT R_GRID EXPORTING I_PARENT = R_CONTAINER. SET HANDLER R_HANDLER->ON_DOUBLE_CLICK R_HANDLER->ON_RIGHT_CLICK FOR ALL INSTANCES ENDIF. ENDMODULE.


*-----------------------*--------------------------------------------------------------------------------------------------*

Module

STATUS_0101 OUTPUT



*-----------------------------------------------------------------------*

PA I INCLUDE

Z_011_ALV_GRID_EVENT_I01 Z_011_ ALV_GRID_EVENT_I01

*-----------------------*------------------------------------------------------------------------------------------------------------------*-----------------------*--------------------------------------------------------------------------------------------------*

Module

USER_COMMAND_0101 INPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE USER_COMMAND_0101 INPUT. CASE OK_CODE . WHEN 'SEARCH'. PERFORM GET_DATA USING

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SFLIGHT-CARRID. CALL METHOD R_GRID->REFRESH_TABLE_DISPLAY. WHEN 'EXIT'. LEAVE PROGRAM. ENDCASE. ENDMODULE.

" USER_COMMAND_0101 INPUT

*-----------------------*---------------------------------------------------------------------------------------------------------------------------*

FORM INCLUDE

Z_011_ALV_GRID_EVENT_F01 Z_011_ ALV_GRID_EVENT_F01

*-----------------------*---------------------------------------------------------------------------------------------------------------------------*-----------------------*--------------------------------------------------------------------------------------------------* FORM

: GET_DATA

* Created : 26.03.2008 12:34:09 *---------------------------------------------------------------FORM GET_DATA USING VALUE(P_CARRID) TYPE SFLIGHT-CARRID. IF P_CARRID IS INITIAL. SELECT * FROM SFLIGHT INTO CORRESPONDING FIELDS OF TABLE IT_SFLIGHT. ELSE. SELECT * FROM SFLIGHT INTO CORRESPONDING FIELDS OF TABLE IT_SFLIGHT WHERE CARRID = P_CARRID. ENDIF. ENDFORM. "GET_DATA ALV GRID CONTROL USING FIELD CATALOGS The internal table with the data to be displayed can have a user-specific line type. In order for the proxy instance to satisfactorily format the data it receives during the screen output or when a print list is created, it requires relevant information known as the field catalog. You can have the proxy instance automatically generate the field catalog. For line types that are defined in the ABAP Dictionary, you only need to inform the proxy instance of the structure's name in the ABAP Dictionary. Alternatively, or in addition to this, you can provide the proxy instance with this display information using an additional internal table. For the sake of simplicity, we will call this additional table a field catalog. The global data type of this internal table is LVC_T_FCAT. Its line type is LVC_S_FCAT. Typical examples of where you need to transfer a field catalog include:

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•

•

The internal table with data has a line type with a dictionary reference, but the display of the column position or heading is different. The internal table has (exclusive or additional) columns that are not contained in a dictionary structure.

For each column in the data table that deviates from an underlying dictionary structure or is not available in a dictionary structure, the field catalog must contain a line that determines the technical characteristics and other column format information. Report : 012 Code listing for: Z_012_ALV_FI ELDCATALOG Description: Description: EXAMP LE OF ALV USING FIELDCATALOG *-----------------------------------*---------------------------------------------------------------------------------------* SCREEN 101 : FLOW LOGIC *-----------------------*--------------------------------------------------------------------------------------------------PROCESS BEFORE OUTPUT. MODULE STATUS_0101. MODULE GET_DATA. MODULE CREATE_OBJECTS. MODULE CREATE_FIELDCAT. MODULE DISPALY_ALV. *-----------------------*--------------------------------------------------------------------------------------------------------------*

MODULE POOL

Z_012_ALV_FIELDC Z_0 12_ALV_FIELDCATALOG ATALOG

*-----------------------*--------------------------------------------------------------------------------------------------------------INCLUDE Z_012_ALV_FIELDCATALOG_TOP. " Global Data INCLUDE Z_012_ALV_FIELDCATALOG_O01. " PBO-Modules INCLUDE Z_012_ALV_FIELDCATALOG_I01. " PAI-Modules INCLUDE Z_012_ALV_FIELDCATALOG_F01. " FORM-Routines *-----------------------*---------------------------------------------------------------------------------------------------------------------*

TOP IN CLUD CLUDE E

Z_012_ALV_FIELDCATALOG_TOP

*--------------------------------------------------------------------------REPORT Z_012_ALV_FIELDCATALOG. TABLES SPFLI. TYPES: BEGIN OF TY_SPFLI, CARRID

TYPE SPFLI-CARRID,

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CONNID

TYPE SPFLI-CONNID,

COUNTRYFR TYPE SPFLI-COUNTRYFR, COUNTRYTO TYPE SPFLI-COUNTRYTO, END OF TY_SPFLI. DATA:

IT_SPFLI TYPE STANDARD TABLE OF TY_SPFLI,

IT_FIELDCAT TYPE LVC_T_FCAT, WA_FIELDCAT LIKE LINE OF IT_FIELDCAT, R_CONTAINER TYPE REF TO CL_GUI_CUSTOM_CONTAINER, R_ALV TYPE REF TO CL_GUI_ALV_GRID. *-----------------------*-----------------------------------------------------------------------------------------------------------------------*

PBO INCLUDE

Z_012_ALV_FIELDCATALOG_O01 Z_012_ALV_FIELDC ATALOG_O01

*-----------------------*-----------------------------------------------------------------------------------------------------------------------*-----------------------*--------------------------------------------------------------------------------------------------*

Module

STATUS_0101 OUTPUT



*-----------------------*--------------------------------------------------------------------------------------------------*

Module

GET_DATA OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE GET_DATA OUTPUT. PERFORM GET_DATA. ENDMODULE.

" GET_DATA OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------*

Module


*-----------------------*--------------------------------------------------------------------------------------------------MODULE CREATE_OBJECTS OUTPUT. PERFORM CREATE_OBJECTS. ENDMODULE.


Page 37 of 40

*-----------------------*--------------------------------------------------------------------------------------------------*

Module

CREATE_FIELDCAT OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE CREATE_FIELDCAT OUTPUT. PERFORM CREATE_FIELDCATALOG. ENDMODULE.

" CREATE_FIELDCAT OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------*

Module

DISPALY_ALV OUTPUT

*-----------------------*--------------------------------------------------------------------------------------------------MODULE DISPALY_ALV OUTPUT. PERFORM DISPLAY_ALV. ENDMODULE.

" DISPALY_ALV OUTPUT

*-----------------------*---------------------------------------------------------------------------------------------------------------------------*

FORM INCLUDE

Z_012_ALV_FIELDCATALOG_F01 Z_012_ALV_FIELDC ATALOG_F01

*-----------------------*----------------------------------------------------------------------------------------------------------------------------*-----------------------*--------------------------------------------------------------------------------------------------* FORM

: GET_DATA

* Created : 26.03.2008 17:24:39 *-----------------------*--------------------------------------------------------------------------------------------------FORM GET_DATA. SELECT CARRID CONNID COUNTRYFR COUNTRYTO FROM SPFLI INTO CORRESPONDING FIELDS OF TABLE IT_SPFLI. ENDFORM. "GET_DATA *-----------------------*--------------------------------------------------------------------------------------------------* FORM

: CREATE_FIELDCATALOG

* Created : 26.03.2008 17:30:03 17:30:03 *-----------------------*--------------------------------------------------------------------------------------------------FORM CREATE_FIELDCATALOG. WA_FIELDCAT-FIELDNAME = 'CARRID'. WA_FIELDCAT-REF_FIELD = 'CARRID'. WA_FIELDCAT-REF_TABLE = 'SPFLI'. WA_FIELDCAT-COL_POS = 0.

Page 38 of 40

WA_FIELDCAT-FIX_COLUMN = 'X'. APPEND WA_FIELDCAT to IT_FIELDCAT. CLEAR WA_FIELDCAT. WA_FIELDCAT-FIELDNAME = 'CONNID'. WA_FIELDCAT-REF_FIELD = 'CONNID'. WA_FIELDCAT-REF_TABLE = 'SPFLI'. WA_FIELDCAT-COL_POS = 1. WA_FIELDCAT-FIX_COLUMN = 'X'. APPEND WA_FIELDCAT to IT_FIELDCAT. CLEAR WA_FIELDCAT. WA_FIELDCAT-FIELDNAME = 'COUNTRY FROM'. WA_FIELDCAT-REF_FIELD = 'COUNTRYFR'. WA_FIELDCAT-REF_TABLE = 'SPFLI'. WA_FIELDCAT-COL_POS = 2. WA_FIELDCAT-FIX_COLUMN = 'X'. APPEND WA_FIELDCAT to IT_FIELDCAT. CLEAR WA_FIELDCAT. WA_FIELDCAT-FIELDNAME = 'COUNTRY TO'. WA_FIELDCAT-REF_FIELD = 'COUNTRYTO'. WA_FIELDCAT-REF_TABLE = 'SPFLI'. WA_FIELDCAT-COL_POS = 3. WA_FIELDCAT-FIX_COLUMN = 'X'. APPEND WA_FIELDCAT to IT_FIELDCAT. CLEAR WA_FIELDCAT. ENDFORM. "CREATE_FIELDCATALOG *-----------------------*--------------------------------------------------------------------------------------------------* FORM

: DISPLAY_ALV

* Created : 26.03.2008 17:24:19 *-----------------------*--------------------------------------------------------------------------------------------------FORM DISPLAY_ALV. CALL METHOD R_ALV->SET_TABLE_FOR_FIRST_DISPLAY

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* *

EXPORTING I_STRUCTURE_NAME = 'SFLIGHT' CHANGING IT_OUTTAB

= IT_SPFLI

IT_FIELDCATALOG

= IT_FIELDCAT.

ENDFORM. "DISPLAY_ALV *-----------------------*--------------------------------------------------------------------------------------------------*

Form CREATE_OBJECTS

*-----------------------*--------------------------------------------------------------------------------------------------FORM CREATE_OBJECTS . CREATE OBJECT R_CONTAINER EXPORTING CONTAINER_NAME = 'CC_ALV'. CREATE OBJECT R_ALV EXPORTING I_PARENT = R_CONTAINER. ENDFORM.

" CREATE_OBJECTS

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Object Oriented ABAP Guide

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