Mixpanel-JS track_form strips the button data from POST about mixpanel-js HOT 2 OPEN

Thanks for pointing this out. The track_forms() helper is a little bit too simple for your scenario: since it only overrides the form submission event rather than clicks on individual form elements, there's no way to re-submit the form programmatically along with a particular submit input's value (see http://stackoverflow.com/questions/1709301/javascript-submit-does-not-include-submit-button-value for some explanations).

There's a fairly lightweight workaround: use a hidden form field to tell your server which button was pressed, and set its value in a click-handler on your submit buttons. Here's an implementation with ugly inline+global JS (if you use jQuery or other libs, this can be cleaner and unobtrusive):

<input id="submit_type" name="submit_type" type="hidden" value="paid">
<input name="free_sub" value="Free" type="submit" onclick="setSubmitType('free')">
<input name="paid_sub" value="Paid" type="submit" onclick="setSubmitType('paid')">
<script>
    function setSubmitType(stype) {
        document.getElementById('submit_type').value = stype;
    }
</script>

then your server-side check can be something like:

patch :confirm, constraints: lambda {|req| req.params[:submit_type] == 'free'}, action: :free_subscribe
patch :confirm

How do you feel about that approach? In general, particular values from submit inputs are difficult to work with in JS, so people often avoid them for anything except the most straightforward HTML form scenarios.

from mixpanel-js.

This is also happening to my team. The workaround proposed by @tdumitrescu sadly can't easily work for us, because our code doesn't generate the form, it's generated by an upstream dependency that we are not allowed to patch... as a possible idea for a fix, could Mixpanel save the information about the pressed submit button, and repackage it, maybe as a hidden input to be sent in the POST request?

from mixpanel-js.