input tag doesnt take attribute

tried to add a oninvalid attribute to an input tag but it seems it doesnt get added for some reason any idea why ?

Thanks for reporting this issue! We have purposefully removed support for on* attributes from the app for security reasons. You will need to add event handlers by writing JavaScript. You can do this with jQuery:

$('#your-input').on('invalid', function(){ /* do stuff here */ });

thats what we did :)