Difference >< Function Modules and BAPI FM's

[Former Member]

What is the Difference >< Normal Function Modules and BAPI FM's ?

[Former Member]

Hi

RFC and BAPIs are remote enabled function modules. They are practicly the same. A BAPI is one step further as it usually is a self contained business function, such as "Create Purchase Order", or "Change Sales Document". BAPIs interface is very well defined and documented. BAPIs can be found in the BAPI browser via transaction BAPI. RFCs are just remote enabled function modules.

BAPI stands for Business Application Programming Interface. It is a library of functions that are released to the public as an interface into an existing SAP system from an external system.

RFC is the protocol used to call functions in an R/3 system by a caller external to R/3 or to call programs external to R/3 from an R/3 system. Functions can only be called via RFC, if they are tagged as RFC functions in the SAP development workbench.

Function Modules;

Check this matter.

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 The additional option of defining table parameters using TABLES is obsolete.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 exception 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 are defined. Class-based exceptions are represented in the above syntax by RAISING, and non-class-based exceptions are represented by EXCEPTIONS.

The addition RAISING is used to declare class-based exceptions that can be propagated from the function module to the caller. Exceptions in the categories CX_STATIC_CHECK and CX_DYNAMIC_CHECK must be explicitly declared, otherwise a propagation can lead to an interface violation. A violation of the interface leads to the treatable exception CX_SY_NO_HANDLER. Exceptions of the category CX_NO_CHECK are implicitly always declared. The declaration of exceptions of the category CX_STATIC_CHECK is statically checked in the syntax check. For exceptions of the category CX_DYNAMIC_CHECK, the check is not performed until runtime. In a function module in which class-based exceptions are declared with the RAISING addition, the statement CATCH SYSTEM-EXCEPTIONS cannot be used. Instead, the relevant treatable exceptions should be handled in a TRY control structure.

The addition EXCEPTIONS is used to define a list of non-class-based exceptions that can be triggered in the function module using the statements RAISE or MESSAGE RAISING. Exceptions defined in this way - as with formal parameters - are bound to the function module and cannot be propagated. If an exception of this type is triggered in a function module, and no return value has been assigned to it with the homonymous addition EXCEPTIONS of the CALL FUNCTION statement when the call was made, this leads to a runtime error.

Note

For new developments after release 6.10, SAP recommends that you work with class-based exceptions that are independent of the function module.

RFC is a technology which is used to access a functions (Modules) from

the remote systems.

If a function module is set as remote enabled which can be access from

the remote system via RFC.Eg: U can access the Remote enabled function modules in ur VB,Webdynpro,Java,Visual composer program.

A function module can be set as remote enabled by SE37->Go to ur FM->click the option Button "remote enabled".

But Normal function modules can not accessd from the remote system.

Good Example for RFC enabled function module is : BAPI(Business Application Programming Interface)

Note: All BAPIs are Remote enabled but not all remote enabled function modules are BAPI.

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.

Also check these links.

http://www.geocities.com/victorav15/sapr3/abapfun.html

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

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

See the following links:

http://help.sap.com/saphelp_erp2005vp/helpdata/en/9f/db970e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_erp2005vp/helpdata/en/9f/db970e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_erp2005vp/helpdata/en/9f/db970e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_erp2005vp/helpdata/en/9f/db970e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_erp2005vp/helpdata/en/9f/db970e35c111d1829f0000e829fbfe/frameset.htm

http://help.sap.com/saphelp_nw04/helpdata/en/26/64f623fa8911d386e70000e82011b8/content.htm

BAPI

BAPI

http://help.sap.com/saphelp_nw2004s/helpdata/en/7e/5e114a4a1611d1894c0000e829fbbd/frameset.htm

http://www.sapgenie.com/abap/bapi/example.htm

http://help.sap.com/saphelp_46c/helpdata/en/9b/417f07ee2211d1ad14080009b0fb56/frameset.htm

http://searchsap.techtarget.com/originalContent/0,289142,sid21_gci948835,00.html

http://searchsap.techtarget.com/originalContent/0,289142,sid21_gci948835,00.html

http://techrepublic.com.com/5100-6329-1051160.html#

http://www.sap-img.com/bapi.htm

http://www.sap-img.com/abap/bapi-conventions.htm

http://www.sappoint.com/abap/bapiintro.pdf

http://www.sapgenie.com/abap/bapi/example.htm

http://help.sap.com/printdocu/core/Print46c/en/data/pdf/BCMIDAPII/CABFAAPIINTRO.pdf

http://help.sap.com/printdocu/core/Print46c/en/data/pdf/CABFABAPIREF/CABFABAPIPG.pdf

http://help.sap.com/printdocu/core/Print46c/en/data/pdf/BCFESDE8/BCFESDE8.pdf

http://help.sap.com/printdocu/core/Print46c/en/data/pdf/CABFABAPIREF/CABFABAPIPG.pdf

http://help.sap.com/printdocu/core/Print46c/en/data/pdf/BCMIDAPII/CABFAAPIINTRO.pdf

Regards

Anji

[Former Member]

Hi Avi,

Functiopn Modules:

Function modules are ABAP routines that are stored in a central function library. They are not application-specific, and available systemwide. The ABAP Workbench comes with a large number of standard function modules.

Some Busniess Logic thats needs repeated execution in System are developed into FM. So Reusibility is the major advantage and no repeated programming.

All related FMs are grouped in Function Groups !

Normally used with the SAP system !

BAPI :

Business Application Programming Interfaces (BAPIs) enable access to SAP functions across formal, stable and dialog-free interfaces. These interfaces can be used by external applications developed by customers and complementary software partners as well as by other SAP applications.

BAPIs are defined as API methods of SAP Business Object Types. These object types are used to enable object-based communication between components. Business objects and their BAPIs enable object orientation to be used in central information processing in companies. For example, you can reuse existing functions and data, achieve trouble-free technical interoperability, and implement non-SAP components.

Applications can use BAPIs to directly access the application layer of the SAP System and, as clients, applications can use the business logic of the SAP System. BAPIs provide the client with an object-oriented view of the application objects, without needing to know the implementation details.

Reusibility is the major advantage !

Even non-SAP application can access SAP system using BAPI for executing certain Business Functionality !

Basically BAPI are designed for the 3rd Software to communicate with SAP system for accessing,creating or modifying some business data lying on the SAP system !

BAPI Function module must be Remote enabled(Only pass by value Parameters allowed).

BAPI Function module cannot have Exceptions.

BAPI Function module must have a parameter called RETURN type BAPIRETURN to return the messages .

BAPI Function module cannot have any statements like CALL SCREEN and

COMMIT WORK

Reward if helpful.

Regards,

Harini.S