tl/dr: How can I do a tMap when both the Main and Lookup tables are dynamic? I've tried linking a tFileOutputExcel to a tFileInputExcel with a OnComponentOK, but it complains that the file is closed.
It seems like this must be a pretty common operation, I'm just missing something. The overall workflow looks like this: Break a large XML document into several separate streams (like Products, Orders, Customers, etc). Then use tMap's to reconnect them in certain required combinations.
You will need to give a little more detail about what you want to achieve. I can't quite figure out why you need dynamic functionality given your description. I assume you are new to Talend and maybe familiar with another DI tool. If so, it might give someone a clue as to what you want to achieve by describing what you want to do in relation to the other tool.