Prevent exit from a block

Question

Dear members,
I have a block on a stacked canvas. I want the user to exit only by clicking on a particular button. Thus I created a POST-BLOCK trigger to raise a form_trigger_failure if the user clicks anywhere else. It just checks if the view is visible. The button then just has to hide the view before exiting, so the trigger lets it do it.
The problem is that I want the user to be able to commit its work while on the block. But when I execute a 'COMMIT_FORM', Forms tries to exit from the block, gets the form_trigger_failure, and stops committing.
The solutions could be:
- To find another way to prevent the user from exiting from the block/canvas,
- To make the difference between a user exit and Forms exit so the trigger can sort it out.
Any clue will be much appreciated.

Answer 1

Let me put it clearer:
Actually, I do have my 'commit_form and exit that block codes' in my button trigger.
But the user can also exit from the block/canvas by clicking anywhere on the main canvas (since they are stacked), what I don't want. The post-block trigger is there to prevent him to do so, by raising a form_trigger_failure (since I can't use a go_block to go back to my canvas).
That means I don't use 'commit_form' in my post-block trigger.
By the way, what's the difference between 'commit_form' and 'FORMS_DDL('commit')' again ?