Flat file idoc to SAP

Hi All,

I have a requirement to send a Flat file Idoc to SAP using XI. I am more interested to know the ABAP mapping techniques and examples for this. I know about File content conversion, ALE port method using RSEINB00 program, XSLT mapping techniques. But I am really waiting for some scenarios and examples someone has already done using ABAP mapping. There is a specific requirement from the client to do it in ABAP mapping and please don't ask me the reason.

Thanks

Ricky