The document API has an example for updating the input data by changing DB connection parameters:
Is there an analogous procedure if the input data comes directly from a file?
I have a bunch of csv files that each hold the data for a specific customer and I'd like to generate a packaged workbook for each of them.
UPDATE: Well, Since no one has better ideas it looks like XML-hacking may still be the easiest way to interact with tableau files to accomplish these sorts of tasks
I found this post on programatically creating workbooks in with data extract API.
Hope this helps!