function module

[Former Member]

can anyone tell me in brief what a function module is actually and a simple code for it

[Former Member]

HI,

Have a look at this link,

http://www.abapprogramming.blogspot.com/2007/06/lesson-24-function-groups-and-function.html

[Former Member]

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,Function modules allow you to encapsulate and reuse global functions in the R/3 System. They are stored in a central library,Unlike subroutines, you do not define function modules in the source code of your program.

3 types.

1)normal function module

2)remote function module

Difference between FM and subroutines

3)update function module

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Check for SAP Help they give you the information in much details

http://help.sap.com/saphelp_nw2004s/helpdata/en/9f/db98fc35c111d1829f0000e829fbfe/frameset.htm

Exercise 1: Creating a Function module

Use

Function modules are ABAP routines that are administered in a central function library. They apply across applications and are available throughout the system. You must assign function modules to a function pool that is called a function group. A function group is nothing but a container for the function modules. Now create a function group and then a function module, which you can use for the next exercise steps.

Procedure

Create a Function Group:

To open the Object Navigator choose from the SAP Menu Overview ® Object Navigator.

From the Object Selection window select Function group, enter FG_Tutorial as name of your function group, and choose Display.

Since the function group FG_Tutorial does not yet exist, the system asks you whether to create it. Confirm with Yes.

Enter a short description and choose Save.

In the window Create Object Catalog Entry choose Local object.

You created a local function group. Before it can receive function modules, you must activate it.

In the object list, use the right mouse button to select the function group FG_Tutorial you just created and choose Activate.

On the next screen choose Continue.

The function group is now active.

Create Global Data:

Within the function group you can declare global data. All function modules of this function group share this global data.

In the Object Selection window open the directory tree Includes and double-click on LFG_TutorialTOP.

Choose Create « Change ( STRG+F1 ) and enter the following data declarations in the tool area:

TABLES spfli.

DATA spfli_workarea LIKE spfli.

Check ( STRGF2 ) and activate ( STRGF3 ) the include file.

Create a Function Module:

Create a function module that reads data from table SPFLI .

If you are not yet in the Object Navigator, choose from the SAP Menu Overview à Object Navigator and display the function group FG_Tutorial .

In the Object selection window, use the right mouse button to select function group FG_Tutorial , and choose Create à Function module.

Enter as function module name XX_RFC_READ_SPFLI and replace XX with the initials of your name.

Enter a short description and choose Save.

The system lists the function module in the object list in a new directory Function modules, and displays it on the right side in the Function Builder.

Select the Attributes tab and under Processing type choose Remote-enabled module.

Select the Import tab and enter in the appropriate columns the names of the import parameters: carrid with reference type like spfli-carrid and connid with reference type like spfli-connid . For each parameter set the Pass value flag.

Select the Export tab and enter in the appropriate columns the names of the export parameters: ex_spfli with reference type like spfli and sys with reference type like sy-sysid . For each parameter set the Pass value flag.

Select the Exceptions tab and enter the exception invalid_data .

Select the Source code tab.

The system copies the entries you made in the other tabs and creates a source text.

Complete the function module with the actual flight data retrieval.

Compare your function with the model solution.

Save the function module ( STRG+S ). When the note on remote-enabled function modules appears, choose Continue.

Check the function for errors ( STRGF2 ) and then activate it ( STRGF3 ).

Test the Function Module:

Choose Test/Execute ( F8 ) or Function module à Test à Test function module.

As import parameter for CARRID enter LH ; for CONNID enter 400 . Leave the RFC target system line empty.

Choose Execute ( F8 ).

The system displays the export parameters EX_SPFLI and SYS in an additional table.

For a detailed display of the data select the value in line EX_SPFLI.

Result

You created a function module and assigned it to a function group.

Continue With

Exercise 2: Implementing a Local Function Call

Regards

vasu

[Former Member]

Funtion module is like a functions(methods) in other langauages like C ,Java etc.,

if u need some repitative operation to be done u can put tht in funtion module(FM)..

go to se37 and create a FM and assign to function group

If the function module was created u can c the tabs like attributes,sourcecode,import,export,exception etc.,

In tht u can write the code in the part of source code and if u wantto pass parameters means u can specify tht in esport and import areas

reward if useful

[Former Member]

Function Modules are special external subroutine stored in a central library. The R/3 system provides numerous predefined function modules that you can call from the ABAP/4 programs.

All the function Modules are created under the Function Groups. Function Groups are nothing but the related group of function modules.

The function modules can be maintained through T.CodeSE37 and T.Code SE80.

In general the function module has the following components.

Documentation:

This is the place where you can find the discription/purpose of the function module.

Import & Export Parameters.

Import parameters correspond to the formal input parameters of subroutines. They pass data from the calling program to the function module.

Export parameters correspond to the formal input parameters of subroutines. They pass data from the function module back to the calling program.

Table Parameters.

Table parameters are internal tables. Internal tables are treated like changing parameters and are always passed by reference.

Exceptions.

Exceptions are used to handle error scenarios which can occur in the function modules. The function modules checks for any type of error and raise exception and returns SY-SUBRC value to the calling program.

Source Code:

the programming logic of the function module is written in this source code.

Rewards if useful.