trackForm will submit a form even if the event has been prevented

[rsobers]

If a form submit event has been prevented by some other code (e.g., because client-side field validation failed), Segment's trackForm will still call submit and essentially override the prevention. As a result, the form will be POSTed and the track calls will be executed even though the action didn't really happen.

I rolled my own version for now which checks event.isDefaultPrevented() and if it's true will bail out before submitting the form or calling track.

I realize this might not be the result everyone wants, just thought I'd raise the issue.

Note: KISSMetrics' trackSubmit is in between--if the event has been prevented, it won't submit the form, but it will track the event (causing event inflation). I think this is because they're not calling prevent but just inserting a delay.

[sperand-io]

@rsobers hey rob! thanks for the heads up on this!

just an fyi — @ianstormtaylor put our heads together here on how to respect the defaultPrevented case going forward, and should have an update in the next day or so

[rsobers]

Thanks for the update @sperand-io!

One thing that's tricky with defaultPrevented is ensuring that the trackForm handler runs last of all the possible event handlers bound to the form submit click.

I haven't dug too deep into how each of the browsers handle it, but from the bit I've read it seems that the handlers fire in the order in which they are bound. Could be tough to control.

[rsobers]

Any updates on this @sperand-io?

HubSpot recently updated their form validation logic. Now, unfortunately, event.isDefaultPrevented() is true regardless of the validity of the form, so the method I suggested is no longer an option with them. I suspect it'll work for other popular landing page vendors still, though.

[benjaminhoffman]

any update on this? I noticed trackForm fires even if form errors.

[snapswerve]

@sperand-io any update here? we're dealing with the same overreporting issue when tracking form submissions on instapage

[jonhilmarg]

Also having this issue, anyone found an easy solution?

[btruong]

@jonhilmarg I encountered the same issue when I started implementing client-side validation on our forms such as jquery validation lib. I stumbled upon this post and implemented it and it proved to be very helpful. https://robsobers.com/tracking-form-submission-events/ Hope this helps. Much props to @rsobers for this post. I just realized you are also on this thread.

[f2prateek]

Tracking internally in JIRA as well https://segment.atlassian.net/browse/LIB-148