LoadRunner Advanced Scripting Techniques Making use of function calls to simplify Scripts
by Nicholas P. M. Godfrey
Introduction Let's suppose that you have ten t en scripts to write and each one starts with a complex login screen, for example. The usual approach appro ach to this would be to record reco rd your scripts one at a time and correlate and parametize each one independently. And if, at a later date, the recorded login functionality changes, each script would wo uld then have to be modified mod ified accordingly. There is however another anot her approach: Record one script and program the login screen until it works. Then, build a function function from this working code c ode and call ca ll this function from within each script that needs to login to the application under test. This document shows how this can be achieved quickly and easily with a minimum of coding knowledge. Just follow the example below. Suppose you want to record a web searching script where each eac h different type of user logs into your site and performs a different search depe nding on their particular business rules. So for each type of user you have a separate script but they all share the t he same initialization function (init()) where they login.
Standard Vugen script The various components of o f your standard recorded script look like this: vuser_init.c (the common login screen)
vuser_init() { web_add_cookie("FPS=dl; DOMAIN=www.webwob.com"); web_add_cookie("B=bjh9s8t2jc687&b=3&s=5n; DOMAIN=www.webwob.com"); web_add_cookie("Q=q1=AACAAAAAAAAAfA--&q2=RYtEeg--; DOMAIN=www.webwob.com"); web_add_cookie("SO=v=0.4&t=1166799707; DOMAIN=www.webwob.com"); web_url("www.webwob.com", "URL=http://www.webwob.com/", "Resource=0", "RecContentType=text/html",
"Referer=", "Snapshot=t1.inf", "Mode=HTTP", LAST); web_concurrent_start(NULL); web_url("y3.gif", "URL=http://us.i1.webwob.com/us.webwob.com/i/ww/beta/y3.gif", "Resource=1", "RecContentType=image/gif", "Referer=http://www.webwob.com/", "Snapshot=t2.inf", LAST); return 0; } Action.c
(variable searching activities)
Action() { web_add_cookie("D=_ylc=X3IDMwRmcANyL3N4&_ylg=X3oDMTQwczUxMzEy; DOMAIN=www.webwob.com"); lr_think_time(15); web_url("p.gif", "URL=http://www.webwob.com/p.gif?t=1166801046&_ylp=A0LEfYGW.ItFtV8AN131 cSkA&, "Resource=1", "RecContentType=image/gif", "Referer=http://www.webwob.com/", "Snapshot=t31.inf", LAST); web_add_cookie("B=bjh9s8t2jc687&b=3&s=5n; DOMAIN=search.webwob.com"); web_add_cookie("Q=q1=AACAAAAAAAAAfA--&q2=RYtEeg--; DOMAIN=search.webwob.com"); web_add_cookie("SO=v=0.4&t=1166799707; DOMAIN=search.webwob.com"); web_url("search",
"URL=http://www.webwob.com/r/sx/*http://search.webwob.com/search?p=Nikon+F-301+1985&fr=yfp-t501&toggle=1&cop=mss&ei=UTF-8&vc=&fp_ip=UK", "Resource=0", "RecContentType=text/html", "Referer=http://www.webwob.com/", "Snapshot=t32.inf", "Mode=HTTP", LAST); return 0; } globals.h (This is used next. See below.)
#ifndef _GLOBALS_H #define _GLOBALS_H //-------------------------------------------------------------------// Include Files #include "lrun.h" #include "web_api.h" #include "lrw_custom_body.h" //-------------------------------------------------------------------// Global Variables #endif // _GLOBALS_H
Modified Vugen script, using a function call Make sure that the login section fully works and then modify the above structure. This is done by introducing a new file and referencing it in the globals.h file, after which it will be possible to call a login() function from within the vuser_init.c section. First, cut and paste the co de from with the vuser_init.c file into a new text file, called mylogin.h , creating a login function at the same time: mylogin.h
login() { web_add_cookie("FPS=dl; DOMAIN=www.webwob.com");
web_add_cookie("B=bjh9s8t2jc687&b=3&s=5n; DOMAIN=www.webwob.com"); web_add_cookie("Q=q1=AACAAAAAAAAAfA--&q2=RYtEeg--; DOMAIN=www.webwob.com"); web_add_cookie("SO=v=0.4&t=1166799707; DOMAIN=www.webwob.com"); web_url("www.webwob.com", "URL=http://www.webwob.com/", "Resource=0", "RecContentType=text/html", "Referer=", "Snapshot=t1.inf", "Mode=HTTP", LAST); web_concurrent_start(NULL); web_url("y3.gif", "URL=http://us.i1.webwob.com/us.webwob.com/i/ww/beta/y3.gif", "Resource=1", "RecContentType=image/gif", "Referer=http://www.webwob.com/", "Snapshot=t2.inf", LAST); return 0; } Save this file somewhere in your file structure. Let's say it is under c:\LRScripts. Next, edit the vuser_init.c file so that it looks like this: vuser_init.c
vuser_init() { login(); return 0; } And edit the globals.h file thus: globals.h (Note the additional line.)
#ifndef _GLOBALS_H #define _GLOBALS_H //-------------------------------------------------------------------// Include Files #include "lrun.h" #include "web_api.h" #include "lrw_custom_body.h" #include "c:\\LRScripts\mylogin.h" //-------------------------------------------------------------------// Global Variables #endif // _GLOBALS_H Using
the new structured Vugen script
If you compile and run your script, everything should work as before but you now have a separate login function, contained within mylogin.h which is called from within vuser_init() . For the next user type, record a new script and save it. Then delete the contents of the new vuser_init() and replace it with this: vuser_init() { login(); return 0; } The new script will now login correctly with no extra correlation or parameterization work required. Note that any parameter lists used within the login() function will need incorporating into the new script but there is a better way to handle such data. Read below.
Passing data into your new function Typically you will want your users to login with their own unique username a nd password. This is best accomplished by passing data directly into your new function through the function call. Data files will still be needed by the calling script but the new login function will not refer to these directly, which is better from a maintenance perspective. To do this, define your function as follows: login(char* username, char* password), so mylogin.h looks like this:
mylogin.h
login(char* username, char* password) { web_add_cookie("FPS=dl; DOMAIN=www.webwob.com"); web_add_cookie("B=bjh9s8t2jc687&b=3&s=5n; DOMAIN=www.webwob.com"); web_add_cookie("Q=q1=AACAAAAAAAAAfA--&q2=RYtEeg--; DOMAIN=www.webwob.com"); web_add_cookie("SO=v=0.4&t=1166799707; DOMAIN=www.webwob.com"); web_url("www.webwob.com", "URL=http://www.webwob.com/", "Resource=0", "RecContentType=text/html", "Referer=", "Snapshot=t1.inf", "Mode=HTTP", LAST); web_concurrent_start(NULL); web_url("y3.gif", "URL=http://us.i1.webwob.com/us.webwob.com/i/ww/beta/y3.gif", "Resource=1", "RecContentType=image/gif", "Referer=http://www.webwob.com/", "Snapshot=t2.inf", LAST); return 0; } Inside mylogin() you can refer to username and password just like any other variable and vuser_init() passes the data into the function like this: login("user_id1", "Password1");
