Hi, 

One of our custom widgets (Traditional web) uses the mouseup event in JavaScript (jQuery) to do detect if we clicked inside or outside the widget.

We noticed that sometimes the mouseup event did not fire. We further pinpointed this down to the following situation:

• It only happens on iOS (or iOS simulated) devices
• It only happens when a FORM widget is on the page.

I strongly suspect that the fastclick.js that is loaded when a FORM widget is used has something to do with this.

I have setup a simple example:
The expression adds the text 'mouseup detected' to the container named ContainerId when a mouseup is detected. The form is just an empty form.

Observed behavior:

• On all devices (not being iOS) clicking and releasing the mouse triggers the mouseup event as expected
• On iOS or simulated devices a SINGLE click will not do anything
• On iOS or simulated devices a DOUBLE click will (sometimes) trigger the mouseup event, but will also give a JS error:
  
• When REMOVING the FORM the problem no longer occurs.

Feel free to try it on this page: https://arthur-haine-coolprofs.outsystemscloud.com/OutSystemsUI_CA/WithForm.aspx
or have a look at the attached GIF.

I have also filed a support case for this.

wondering if anyone recognizes this behavior?

Kind regards,

Arthur Haine