topic Re: function modules in Application Development and Automation Discussions

function modules

Former Member — Wed, 09 May 2007 05:44:55 GMT

what is the function module? what is the use of functin module in abap?

Re: function modules

Former Member — Wed, 09 May 2007 05:47:44 GMT

Function Module is one of the modularization techniques.

similar to funstions in C, C++

If there is some code which is getting repeated many no. of times in ur code. then u will write that code in a FM and u will call tat FM where ever that code is getting repeated.

Thats all.

Funtion Modules, Routines, Includes are all comes under the modularization techniques.

Award if uesful,

Sudheer

Re: function modules

former_member196299 — Wed, 09 May 2007 06:16:13 GMT

hi sandya,

Function modules in ABAP are one of the modularization techniques . Here you write a block of code for a specific function or operation. You have import parameters , export parameters, tables , exceptions involved in function modules .

Function modules are reusable in programs .

Regards,

Ranjita

Re: function modules

Former Member — Wed, 09 May 2007 06:37:19 GMT

Hi Sandya,

Check this info.

Function Modules are Global ABAP programs created by SAP for reusable purpose. They have IMPORT, EXPORT and TABLE parameters, and EXCEPTIONS to through when error occurs.

You can create them from TCode SE37.

Go through the following doc:

Function modules are cross-program, reusable procedures that are organized into function groups, and whose functions are implemented between the statements FUNCTION and ENDFUNCTION. Function modules and their interfaces are created in the Function Builder.

Function Module Interfaces

The parameter interface of a function module is defined in the Function Builder. It includes the definition of interface parameters and the specification of exceptions that can be triggered by a function module. The Function Builder automatically generates comment lines below the FUNCTION statement in the source code of the function module, which represent the interface of the function module with the following syntax:

Syntax

... [IMPORTING parameters]

[EXPORTING parameters]

[CHANGING parameters]

[TABLES table_parameters]

[{RAISING|EXCEPTIONS} exc1 exc2 ...]

The syntax and semantics of IMPORTING, EXPORTING, CHANGING, RAISING, and EXCEPTIONS mainly correspond to the definition of method interfaces with [CLASS-]METHODS. The additional option of defining table parameters using TABLES is obsolete.

Interface parameters

The interface parameters are defined on the relevant tab pages in the Function Builder.

IMPORTING parameters are input parameters. When the function module is called, a suitable actual parameter must be specified for every non-optional input parameter. The content of the actual parameter is passed to the input parameter when the call is made. The content of an input parameter for which 'pass by reference' is defined cannot be changed in the function module.

EXPORTING parameters are output parameters. When the function module is called, a suitable actual parameter can be specified for every output parameter. The content of an output parameter that is defined for 'pass by value' is transferred to the actual parameter if the function module is completed without errors. An output parameter that is defined for pass by reference is not initialized when the function module is called.

CHANGING parameters are input and output parameters. When the function module is called, a suitable actual parameter must be specified for every non-optional input or output parameter. When the function module is called, the content of the actual parameter is passed to the input/output parameter, and when the function module is completed, the content of the input/output parameter is passed to the actual parameter.

TABLES parameters are table parameters. Table parameters are obsolete CHANGING parameters that are typed as standard tables with a header line. If an internal table without a header line or a table body is passed as an actual parameter to a formal parameter of this type, an empty local header line is generated in the function module. If an internal table with a header line is used as an actual parameter, both the table body and the header line are passed to the function module. Pass by value is not possible in formal parameters defined using TABLES. Formal parameters defined with TABLES can be replaced by formal parameters defined with CHANGING. A local work area can be created for the internal table in the function module by using the addition LIKE LINE OF itab of the DATA statement.

Exceptions

The exceptions of a function module are defined on the Exceptions tab page in the Function Builder. Here you can select exception classes to define whether class-based exceptions are declared or non-class-based exception is defined. Class-based exceptions are represented in the above syntax by RAISING, and non-class-based exceptions are represented by EXCEPTIONS.

CALLING A FUNCTION MODULE:

1)In U ABAP Editor --> Click "Patter" ---> Selection Option Button "Call Function"

--> Write the Corresponding FM name --> Hit Enter

2)The appropriate import ,export Parameters will be displayed in ur editor

3)Pass the Values Here.

Check this link:

http://help.sap.com/saphelp_erp2004/helpdata/en/9f/db988735c111d1829f0000e829fbfe/content.htm

http://help.sap.com/saphelp_nw2004s/helpdata/en/ef/d94b78ebf811d295b100a0c94260a5/frameset.htm

http://help.sap.com/saphelp_nw2004s/helpdata/en/43/41341147041806e10000000a1553f6/frameset.htm

Hope this resolves your query.

Reward all the helpful answers.

Regards

Re: function modules

Former Member — Wed, 09 May 2007 06:46:42 GMT

Hi,

Function Modules

Function modules are procedures that are defined in special ABAP programs only, so-called function groups, but can be called from all ABAP programs. Function groups act as containers for function modules that logically belong together. You create function groups and function modules in the ABAP Workbench using the Function Builder.

Function modules allow you to encapsulate and reuse global functions in the SAP System. They are managed in a central function library. The SAP System contains several predefined functions modules that can be called from any ABAP program. Function modules also play an important role during updating and in interaction between different SAP systems, or between SAP systems and remote systems through remote communications.

Unlike subroutines, you do not define function modules in the source code of your program. Instead, you use the Function Builder. The actual ABAP interface definition remains hidden from the programmer. You can define the input parameters of a function module as optional. You can also assign default values to them. Function modules also support exception handling. This allows you to catch certain errors while the function module is running. You can test function modules without having to include them in a program using the Function Builder.

The Function Builder also has a release process for function modules. This ensures that incompatible changes cannot be made to any function modules that have already been released. This applies particularly to the interface. Programs that use a released function module will not cease to work if the function module is changed.

Hope this helps u..

****reward points if useful!

Re: function modules

Former Member — Wed, 09 May 2007 07:06:18 GMT

Hi,

hope, it will be useful for u..

Function modules are ABAP routines that are stored in a central function library.The ABAP Workbench comes with a large number of standard function modules.The function modules encapsulate program code, and provide an interface for data exchange.

Function modules must belong to a pool called a function group.
They possess a fixed interface for data exchange. This makes it easier for you to pass input and output parameters to and from the function module
You call a function module by its name (which must be unique) in a CALL FUNCTION statement.

Function modules play an important role in the modularization of applications. You can use them to encapsulate a particular function or group of related functions.The Modularization allows you to avoid redundancy. It also makes your programs easier to read and understand.Modularized programs are easier to maintain and keep up-to-date.

Warm Regards,

Gopinathan.T

Re: function modules

Former Member — Wed, 09 May 2007 08:32:33 GMT

Hi Sandhya

Function modules are mainly used for "Code Reusability"....If once you wrote a peice of code for a particular program say

//sum

int a ,b,result.

result =a+b.

print result.

if suppose you want to use the same code in some other program,u no need to write it again,you can save the memory capacity as well as time.

Same way ABAP also has function modules which performs many functions which is used in other programs too...

REWARD PLEASE...

Re: function modules

Former Member — Wed, 09 May 2007 09:32:06 GMT

Hi,

U have to award points for useful answers and u have to mention it as Solved if ur question is solved. Dont forget.

Regards,

Sudheer

Re: function modules

Former Member — Wed, 09 May 2007 12:46:02 GMT

Hai,

Function module is just like a procedure to call from a report program.

It does very imp roles in SAP-ABAP.

For that you need to go through the whole link below:

http://help.sap.com/saphelp_nw2004s/helpdata/en/43/41341147041806e10000000a1553f6/frameset.htm

Regards,

Rama chary.Pammi

Re: function modules

Former Member — Wed, 09 May 2007 13:17:12 GMT

Function modules are procedures that are defined in function groups (special ABAP programs with type F) and can be called from any ABAP program. Function groups act as containers for function modules that logically belong together. You create function groups and function modules in the ABAP Workbench using the Function Builder.

Function modules allow you to encapsulate and reuse global functions in the R/3 System. They are stored in a central library. The R/3 System contains a wide range of predefined function modules that you can call from any ABAP program. Function modules also play an important role in database updates and in remote communications between R/3 Systems or between an R/3 System and a non-SAP system.

Function Builder: Transaction code SE37: The Function Builder allows you to create, test, and administer function modules in an integrated environment.

e.g. A sample program to use function module in ABAP code

PROGRAM CALL_FUNCTION.

DATA: TEXT(10) TYPE C VALUE '0123456789',

TEXT1(6) TYPE C,

TEXT2(6) TYPE C.

PARAMETERS POSITION TYPE I.

CALL FUNCTION 'STRING_SPLIT_AT_POSITION'

EXPORTING

STRING = TEXT

POS = POSITION

IMPORTING

STRING1 = TEXT1

STRING2 = TEXT2

EXCEPTIONS

STRING1_TOO_SMALL = 1

STRING2_TOO_SMALL = 2

POS_NOT_VALID = 3

OTHERS = 4.

CASE SY-SUBRC.

WHEN 0.

WRITE: / TEXT, / TEXT1, / TEXT2.

WHEN 1.

WRITE 'Target field 1 too short!'.

WHEN 2.

WRITE 'Target field 2 too short!'.

WHEN 3.

WRITE 'Invalid split position!'.

WHEN 4.

WRITE 'Other errors!'.

ENDCASE.

Hope this sort out your issue.

PS If the answer solves your query, plz close the thread by rewarding each reply.

Regards

Re: function modules

Former Member — Thu, 10 May 2007 04:11:49 GMT

The basic functions in all other languages is the same concept for function modules also..One thing here when we call the function modules means it will itself come up wth the values what we want give(Export and import)along with the exceptions which we defined in it...

Once we have created a function module it can be used in all abap pgms

Re: function modules

Former Member — Thu, 04 Oct 2007 05:37:55 GMT