In my two last posts, I laid out the technical design of the Preview Posting feature, and then showed how to simplify its design to get around the unwanted behavior of TryFunction.
One thing is obvious from these posts: Preview Posting wants to simulate posting of a document (or journal) to show what the results would be, but without leaving any actual trace in the database. In database lingo – we want the transaction to be rolled back.
Rolling back is no brainer. Simply throw an error, or do a silent abort, Except if there is COMMIT. In that case, no rolling back helps.
I have announced earlier that my today’s post will be about how to nest transactions in C/AL so that an inner COMMIT has no effect on the transaction as a whole, which can still be successfully rolled back.
That’s what this post is about.