In computer software, a user exit is a place in a software program where a customer can arrange for their own tailor-made program to be called.
In the R/3 system from SAP, a user exit is contrasted with a customer exit and allows a customer's developer to access program components and data objects within the R/3 system. In R/3, some user exits use Include statements to include customer program enhancements that are called from the program.
Other user exits use tables that are accessed through customization.
Overview
Extension of SAP functionality
SAP makes different possibilities available to extend SAP functionality in the R/3 without modifying the delivered R/3-Standard. Thus these extensions are further present also after a R/3-Release-Wechsel.
• User exit
• Field exit
• Text extensions
• Customer exit
• Table extensions
1. User exit
User exits are original one in the selling module (SD) developed expandability.
They consist of empty subroutines (FORM) in special Includes, which can be filled by a ABAP Use developer.
In special places in the SA P-CODE such subroutine references were inserted by SAP. An extension is thus only possible, where SAP planned it.
They usually offer a rather rudimentary expandability, since purely technically objects in the SAP name area are modified.
2. Field exit
Field exits are bypasses of a Dynprofield with data element purchase into a functional module. These will go through when leaving the Dynpros. There are global and local field exits.
Global field exits
are not limited to a Dynpro. If a data element is used on several Dynpros, after activation of the field exit with all this Dynpros to a functional module one branches out.
Local one field exit
work only on a Dynpro limited. There is the possibility of putting on bus to 36 local field exits to a data element.
3. Text extensions
With text extensions it acts around user keywords and user documentation (F1-Hilfe) to data elements. The new keywords can refer to SAP documentation and to user documentation. Thus one has also the possibility of overwriting the keywords delivered by SAP.
With text extensions the changes are global effective for all SAP applications concerned contrary to application extensions after activation.
4. Customer exit
An application function can be extended by application extensions by the customer. Customer exits must be intended by SAP. They consist generally of several components. The interface SAP/Kunde is clearly defined.
With a R/3-Release-Wechsel and/or. Upgrade remain the customer extensions without effort.
• Function exit
• Menu exit
• Dynpro exit
A) Function exit
By functional module exits the customer can implement additional logic in an application function.
SAP built such exits in different places into many application functions. Thus are the interfaces are already given, and/or which data handed over.
These functional modules can be filled now by the customer. It can insert also user Dynpros with associated processing logic and GUI surface and put on user text elements.
B) Menu exit
Menu exits make it for the customer possible to build and occupy with a function code in an SAP application new menu entries.
SAP determined, where in the program additional function codes are queried and like to it is being reacted, either by a functional module exit or by an already firmly given functionality.
C) Dynpro exit
Dynpro exits permit the customer to arrange ranges of a dynpros reserved by SAP. Within these ranges large information can be indicated or data be seized. Those for this force fields by the customer on a user Dynpro are arranged.
In Details
What is User Exits?
The following document is about exits in SAP: -
The R/3 enhancement concept allows you to add your own functionality to SAP’s standard business applications without having to modify the original applications.
SAP creates user exits for specific programs, screens, and menus within standard R/3 applications.
These exits do not contain any functionality. Instead, the customer exits act as hooks. You can hang your own add-on functionality onto these hooks.
Types of Exits
There are several different types of user exits. Each of these exits acts as hooks where you can attach or "hang" your own add-ons.
Menu Exits
Menu exits add items to the pulldown menus in standard SAP applications. You can use these menu items to call up your own screens or to trigger entire add-on applications.
SAP creates menu exits by defining special menu items in the Menu Painter. These special entries have function codes that begin with "+" (a plus sign). You specify the menu item’s text when activating the item in an add-on project.
Screen Exits
Screen exits add fields to screens in R/3 applications. SAP creates screen exits by placing special subscreen areas on a standard R/3 screen and calling a customer subscreen from the standard screen’s flow logic.
Function Module Exits
Function module exits add functions to R/3 applications. Function module exits play a role in both menu and screen exits.
When you add a new menu item to a standard pull down menu, you use a function module exit to define the actions that should take place once your menu is activated.
Function module exits also control the data flow between standard programs and screen exit fields.
SAP application developers create function module exits by writing calls to customer functions into the source code of standard R/3 programs.
These calls have the following syntax:
CALL CUSTOMER-FUNCTION ‘001’.
Field Exits
Field exits allow you to create your own programming logic for any data element in the Dictionary. You can use this logic to carry out checks, conversions, or business-related processing for any screen field. Example: The data element BBBNR identifies a company’s international location number. You might want to set up your R/3 System so that all international location numbers are larger than 100.
The field exit concept lets you create a special function module that contains this logic.
You assign the special function module to the data element BBBNR. You then assign the module to any programs and screens in which users can add new international location numbers. When you activate your field exit, the system automatically triggers your special routine whenever a user enters a company location number.
In 4.6c, you can use "RSMODPRF" program to create field exits.
An example of a user exits :-
MODULE user_exit_0001 INPUT
CASE okcode.
WHEN 'BACK OR EXIT'.
CASE sy-dynnr.
WHEN '100'.
SET SCREEN 0.
LEAVE SCREEN.
WHEN '200'.
******************************************************************************
**** Note that you can write any code that satisfy your needs. ****
**** But in this case, this was wrote as a sample code for reference sake. ****
**** And you can test it. ****
******************************************************************************
SET SCREEN 100.
LEAVE SCREEN.
ENDCASE.
ENDCASE.
SAP User Exits Routine
User exits are routine which SAP allows you to add in additional customized programs process without affecting the standard SAP programs.
SAP user exit are usually declare as a form routine :-
form userexit_xxxxx
........................
endform
In VL01 - Create Delivery Order, standard program SAPMV50A, the standard program did not check for storage location equal to space, and delivery quantity less than one when the user click the save button. Therefore I have to insert the additional checking into the userexit routine.
Steps:-
• Goto transaction VL01 to pick a Sales Order for delivery (you don't have to save the data)
• In the initial screen, click System -> Status -> Double click on Program (Screen)
• In the dialog program SAPMV50A, click Edit -> Search/replace
• Type userexit in the Find field, then click the In program radio button and hit Enter
• A number of userexit routines will be displayed. You'll have to roughly decide which is the correct userexit routine to used.
Another way of determining the list of user exits could be bus executing the Tcode SE80.
For example if U need to search for the user exits for the above mentioned program, execute the Tcode SE80 and enter the above program name,
The highlighted row denotes a user exit, which is used in this program
form userexit_save_document_prepare.
case xlips-pstyv.
when 'TAX' or 'REX'.
* Accept this two Delivery item category
when 'REN'.
if xlips-lgort = space.
* Reject this Delivery item category
message e001.
endif.
when others.
if xlips-matnr <> space.
* Check storage location not space
if xlips-lgort = space.
message e002.
endif.
* Check delivery quantity not zero
if xlips-pikmg < pgmid =" 'R3TR'" object =" 'PROG'" obj_name =" tstc-pgmna." name =" tstc-pgmna." pname =" tstc-pgmna." funcname =" tfdir-funcname." pgmid =" 'R3TR'" object =" 'FUGR'" pgmid =" 'R3TR'" object =" 'SMOD'" devclass =" v_devclass." sprsl =" sy-langu" name =" jtab-obj_name." zzzz =" up">Bus.transactions->Base parameters->Validation
/NORFB->Bus.transactions->Base parameters->Substitution
Example
=ULTE "FI_DOCU 001 "Parked SA,FY,SI=>long text CORRESP. "
=U&VALID_WBS_IN_ZUONR "FI_ITEM 011 Spon.Res: Check WBS valid in ZUONR"
* changed in 4.5B (* Form UFIA -- formerly U&VALID_WBS_IN_ZUONR)
User exits are form routines that the user programs. There are two types of
user-exits:
1. Validation exits are used in the prerequisites and checks. They have either the value 'T' for true or 'F' for false. They are interpreted as a part of the logical statement, like a constant or field comparison. For this type of user exit, you must fill a parameter with the results of your check ('T' for true; 'F' for false).
Example
FORM Uzzzz USING B_RESULT. "'T' or 'F'
from program ZGGBR000 (ZGGBRI03)
2. Substitution exits are used to change one or more fields. However, you can only change those fields that are permitted in the Boolean class for the substitution. You can display these fields by selecting the following menu options in substitution maintenance:
Thursday, April 10, 2008
USER EXITS IN DETAIL
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