Modify existing program

Question

Hello friends,
Can we modify any existing SAP program.
I heard we need Access key? is it true ?
What is the difference between Access key and developer key?

Answer 1

You have to get access key to modify the standard SAP programs. However you can use BADIs, Exits to make some enhancements or modifications.
BADIs are explained as below:
Business Add-Ins
Business Add-Ins are a new SAP enhancement technique based on ABAP Objects. They can be inserted into the SAP System to accommodate user requirements too specific to be included in the standard delivery. Since specific industries often require special functions, SAP allows you to predefine these points in your software.
As with customer exits (SMOD/CMOD [Page 40]), two different views are available:
• In the definition view, an application programmer predefines exit points in a source that allow specific industry sectors, partners, and customers to attach additional software to standard SAP source code without having to modify the original object.
• In the implementation view, the users of Business Add-Ins can customize the logic they need or use a standard logic if one is available.
In contrast to customer exits, Business Add-Ins no longer assume a two-system infrastructure (SAP and customers), but instead allow for multiple levels of software development (by SAP, partners, and customers, and as country versions, industry solutions, and the like). Definitions and implementations of Business Add-Ins can be created at each level within such a system infrastructure.
SAP guarantees the upward compatibility of all Business Add-In interfaces. Release upgrades do not affect enhancement calls from within the standard software nor do they affect the validity of call interfaces. You do not have to register Business Add-Ins in SSCR.
The Business Add-In enhancement technique differentiates between enhancements that can only be implemented once and enhancements that can be used actively by any number of customers at the same time.
In addition, Business Add-Ins can be defined according to filter values. This allows you to control add-in implementation and make it dependent on specific criteria (on a specific Country value, for example). All ABAP sources, screens, GUIs, and table interfaces created using this enhancement technique are defined in a manner that allows customers to include their own enhancements in the standard.
A single Business Add-In contains all of the interfaces necessary to implement a specific task. In Release 4.6A, program and menu enhancements can be made with Business Add-Ins. The actual program code is enhanced using ABAP Objects. In order to better understand the programming techniques behind the Business Add-In enhancement concept, SAP recommends reading the section on ABAP Objects
DEFINING THE BADI
1) execute Tcode SE18.
2) Specify a definition Name : ZBADI_SPFLI
3) Press create
4) Choose the attribute tab. Specify short desc for badi.. and specify the type :
multiple use.
5) Choose the interface tab
6) Specify interface name: ZIF_EX_BADI_SPFLI and save.
7) Dbl clk on interface name to start class builder . specify a method name (name,
level, desc).
Method level desc
Linese;ection instance methos some desc
8) place the cursor on the method name desc its parameters to define the interface.
Parameter type refe field desc
I_carrid import spfli-carrid some
I_connid import spefi-connid some
9) save , check and activate…adapter class proposed by system is
ZCL_IM_IM_LINESEL is genereated.
IMPLEMENTATION OF BADI DEFINITION
1) EXECUTE tcode se18.choose menuitem create from the implementation menubar.
2) Specify aname for implementation ZIM_LINESEL
3) Specify short desc.
4) Choose interface tab. System proposes a name fo the implementation class.
ZCL_IM_IMLINESEL which is already generarted.
5) Specify short desc for method
6) Dbl clk on method to insert code..(check the code in “AAA”).
7) Save , check and activate the code.
Some useful URL
http://www.esnips.com/doc/e06e4171-29df-462f-b857-54fac19a9d8e/ppt-on-badis.ppt
http://www.esnips.com/doc/10016c34-55a7-4b13-8f5f-bf720422d265/BADIs.pdf
http://www.esnips.com/doc/43a58f51-5d92-4213-913a-de05e9faac0d/Business-Addin.doc
http://www.esnips.com/doc/1e10392e-64d8-4181-b2a5-5f04d8f87839/badi.doc
www.sapgenie.com/publications/saptips/022006%20-%20Zaidi%20BADI.pdf
http://www.sapdevelopment.co.uk/enhance/enhance_badi.htm
http://help.sap.com/saphelp_nw04/helpdata/en/04/f3683c05ea4464e10000000a114084/content.htm
http://help.sap.com/saphelp_nw04/helpdata/en/e6/d54d3c596f0b26e10000000a11402f/content.htm
http://help.sap.com/saphelp_nw2004s/helpdata/en/c2/eab541c5b63031e10000000a155106/frameset.htm
Now write a sample program to use this badi method..
Look for “BBB” sample program.
“AAA”
data : wa_flights type sflight,
it_flights type table of sflight.
format color col_heading.
write:/ 'Flight info of:', i_carrid, i_connid.
format color col_normal.
select * from sflight
into corresponding fields of table it_flights
where carrid = i_carrid
and connid = i_connid.
loop at it_flights into wa_flights.
write:/ wa_flights-fldate,
wa_flights-planetype,
wa_flights-price currency wa_flights-currency,
wa_flights-seatsmax,
wa_flights-seatsocc.
endloop.
“BBB”
*& Report ZBADI_TEST *
REPORT ZBADI_TEST .
tables: spfli.
data: wa_spfli type spfli,
it_spfli type table of spfli with key carrid connid.
*Initialise the object of the interface.
data: exit_ref type ref to ZCL_IM_IM_LINESEL,
exit_ref1 type ref to ZIF_EX_BADISPFLI1.
selection-screen begin of block b1.
select-options: s_carr for spfli-carrid.
selection-screen end of block b1.
start-of-selection.
select * from spfli into corresponding fields of table it_spfli
where carrid in s_carr.
end-of-selection.
loop at it_spfli into wa_spfli.
write:/ wa_spfli-carrid,
wa_spfli-connid,
wa_spfli-cityfrom,
wa_spfli-deptime,
wa_spfli-arrtime.
hide: wa_spfli-carrid, wa_spfli-connid.
endloop.
at line-selection.
check not wa_spfli-carrid is initial.
create object exit_ref.
exit_ref1 = exit_ref.
call method exit_ref1->lineselection
EXPORTING
i_carrid = wa_spfli-carrid
i_connid = wa_spfli-connid.
clear wa_spfli.
Customer User Exits:
Customer Exit is a hook and also we have to add our own functionality so we have to write the code in include file and activate that project in CMOD.
Whereas in User Exit ,we are writing the code in SAP namespace. So am thinking that its no need to create project and activating that project for user exit. Is it right? For User Exit also we have to create project please clarify me
User Exits:
User exits allow you to add additional functions to the SAP standard.
Programs with user exits contain subroutine calls at certain points in their syntax that are identified by the prefix USEREXIT. The actual user exits are located in an include that has been assigned to a module pool. This is where customers can include any changes (enhancements) that they want to make to the system. These includes are always processed during program flow.
Advantage: In principle, customers can modify anything they want that is found in the include (tables, structures, and so forth).
Disadvantage: SAP cannot check the individual enhancements themselves which often leads to errors in the enhancement process.
User exits (Function module exits) are exits developed by SAP. The exit is implemented as a call to a function module. The code for the function module is written by the developer. You are not writing the code directly in the function module, but in the include that is implemented in the function module.
Customer exits are not available for all programs and screens found in the SAP System. You can only use customer exits if they already exist in the SAP System.
Customer Exit
SAP creates customer exits for specific programs, screens, and menus within standard 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.
If you want to enhance the functionality of your SAP System, you should take advantage of the exits available in standard applications. There are two main reasons why you should use exits rather than modifying SAP software yourself. Add-ons attached to exits have the advantage that:
• They do not affect standard SAP source code
When you add new functionality to your SAP System using SAP’s exits, you do not alter the source code of standard SAP programs in any way. The code and screens you create are encapsulated as separate objects. These customer objects are linked to standard applications, but exist separately from SAP’s standard software package.
• They do not affect software updates
When you add new functionality to your SAP System using SAP’s exits, your objects (called customer objects) must adhere to strict naming conventions. When it comes time to upgrade a to a new software release, customer objects’ names ensure that they will not be affected by any changes or new additions to the standard software package.
Customer exits are not available for all programs and screens found in the SAP System. You can only use customer exits if they already exist in the SAP System. You can find more information about locating applications with pre-defined exits in Locating Applications that have Exits