Undefined ufAlert instance raises a crash in ufForm

This line brings my ufForm to crash cause of the ufAlert has an undefined instance in this case
at this point.
As result...the submit of the ufForm is not working and i get a redirect to the post api url.

[lcharette]

I've seen this before on my custom Js plugin. The alert is probably not initialized yet at that point. Would need to add something similar to this line.

[alexweissman]

@kevinrombach just out of curiosity, what is triggering this condition in the first place? Which browser are you testing this in?

[Silic0nS0ldier]

Just replicated this. What's happening, is that when the msgTarget doesn't actually exist (jQuery doesn't care if it finds nothing, so no early errors), ufAlerts obviously cannot be used.

The error raised is: TypeError: instance is undefined. This error is raised from the submit handler, when it attempts to use ufAlerts.

Fix for this can go 2 ways:

1. Officially make ufAlerts optional (which would just involve an existence check on msgTarget).
2. Throw an error when msgTarget doesn't exist, so that it is clear why the error was raised.

This can affect some of the other plugins too. Probably a good idea to patch them against this sort of error too.

[Silic0nS0ldier]

Thinking about this more, option 1 is a terrible idea. It would make it too easy for bugs to slip through testing given the number of ways ufForm is used. 2 looks to be the only sane way to resolve this.