Function Module: Interface Description and Procedure 

A description of the interface for a function module that is used for generic data extraction:

Importing Parameter

I_DSOURCE type SRSC_S_IF_SIMPLE-DSOURCE DataSource

I_INITFLAG type SRSC_S_IF_SIMPLE-INITFLAG Initialization call

I_MAXSIZE type SRSC_S_IF_SIMPLE-MAXSIZE package size

I_REQUNR type SRSC_S_IF_SIMPLE-REQUNR request number

Tables

I_T_SELECT type SRSC_S_IF_SIMPLE-T_SELECT

I_T_FIELDS type SRSC_S_IF_SIMPLE-T_SELECT

E_T_DATA

Exceptions

NO_MORE_DATA

ERROR_PASSED_TO_MESS_HANDLER

Details on Individual Parameters

·        I_INITFLAG

This parameter is set to ‘X’ when the function module is called up for the first time, then to ‘ ‘.

·        I_MAXSIZE

This parameter contains the number of lines expected within a read call.

Extraction Process

...

The function module is called up again and again during an extraction process:

       1.      Initialization call:

Only the request parameters are transferred to the module here. The module is as yet unable to transfer data.

       2.      First read call:

The extractor returns the data typified with the extract structure in an interface table. The number of rows the system expected is determined in the request parameter (I_MAXSIZE).

       3.      Second read call:

The extractor returns the data enclosed within the first data package in a separate package with I_MAXSIZE rows.

       4.      The system calls up the function module again and again until the module returns the exception NO_MORE_DATA. Data cannot be transferred in the call in which this exception is called up.

Example

An example of a function module that meets these demands is RSAX_BIW_GET_DATA_SIMPLE. A simple way of creating a syntactically correct module is to copy it into its own function group and then to cope the rows of the top-include of function group RSAX (LRSAXTOP) into the top-include of its own function group. Afterwards, the copied function module must be adjusted to the individual requests.