SAP Core | SAP core functionalities and technologies
SAP ALE user exit for IDocs modification
When an IDoc needs to be modified before being sent or posted, user exit EXIT_SAPLBD11_001 may be used by implementing the source code in include ZXSBDU01.
This function module is executed when standard SAP exit ALE00001 is active (transaction SMOD).
The most important available parameters are the IDoc control record (as import and export parameter) and the IDoc data organized following the IDoc segments (structure EDIDD).
The IDoc control record may be used to determine what IDoc type (DEBMAS, CREMAS, …) is being processed, if the IDoc is incoming or outgoing, what is its status and much more. The data internal table may be modified (new data segments may even be inserted) in order to modify the IDoc content.
However, if I remember well, when modifying an outgoing IDoc (exit implemented in the sending system thus) there is no possibility to make the source code implementation partner specific. This is due to the fact that the exit is called before the communication layer has been passed through and the final partners get identified. In such case it is usually better to implement a different version of the source code in each of the receiving systems.