Warning logic issue

[MelissaPage480]

Current version:
Upgraded from:
Issue on tablet and/or server: Tablet only

Expected behavior

After correcting the cause of a warning and selecting Next once, the user should be able to proceed.

Actual behavior

After correcting the cause of a warning the warning still shows after selecting Next. The user needs to click next a second time to proceed

Steps to reproduce the behavior

Enter a value into a question that should throw a warning error then click next. Once the error throws, then change that value to something in the correct range and click next once.

[esurface]

I took a look at this issue but am only able to reproduce it intermittently on the tablet, which disconnected from the dev tools over USB. I suggest we watch this issue and close it if it seems to only be applicable in this one case.

[rjcorwin]

If this is an intermittent issue, it could be due to a race condition, which would explain why it's happening on tablets because tablets are much more prone to intermittent race conditions due to having less powerful processors that fluctuate in their ability to prioritize instructions from the open app.

Race conditions in JS are often caused by code that have entered "async" mode. Any time you see an HTTP request, a setTimeout(), a separate execution stack is created that can compete with the stack it came from. We've intentionally kept Tangy Form in synchronous mode, with rare exceptions such as GPS input. I wonder if something like a setTimeout() slipped in there somewhere causing this race condition...

[rjcorwin]

Thank you @esurface and @MelissaPage480 for your help researching this so far! My suspicion is that the added complexity in tangy-form-item.js we had to add to validation in order to support warnings is getting tripped up.

[esurface]

Digging deeper I found that I can reproduce the issue on the tablet while hooked up to the debugger. There is some combination of validation code, the 'value-change' -> 'change' events cascade that occurs when the text changes, and the re-applying of the 'show-if' statement that causes the 'Next' button to not fire the validation() function.

[esurface]

This is a known issue with paper-button dating back to 2015. According to @rjsteinert they have since moved on to work on another library. For now users can workaround the issue by clicking a second time on the button.

[esurface]

Keeping open to track for release issues