Why do I get a concurrency error when hitting Enter without a submit button in EWL?

Question

I have a page with some form items and an EwfLink (not a submit button). If I post back by hitting enter on any of the form fields, I get a concurrency error (even if I didn't change anything). If I don't do that, the page otherwise works. What's going on?

Answer 1

In HTML, some form controls will post the form when Enter is pressed even if there is no submit button. See http://www.whatwg.org/specs/web-apps/current-work/multipage/association-of-controls-and-forms.html#implicit-submission. You got a concurrency error because, since there was no submit button, EWF was not expecting an implicit-submission post-back to occur.

I recently improved EWF's support for this situation; see https://enduracode.kilnhg.com/Code/Ewl/Group/Bill/History/a91e41468f96. EWF now throws a helpful exception if you try to build a page that includes implicit-submission form controls but no submit button.