Issue with Pre-filled forms

Hey There,

I have run into an issue with Squarespace's javascript related to forms. On our site, I have custom code to pre-fill user information into some forms. Here is a basic example:

$(document).ready(function() {
  var myForms = document.getElementsByClassName('form-wrapper');
		for (var i=0; i < myForms.length; i++) {
			formFiller(myForms[i]);
        }
});

function formFiller(thisForm) {
       //console.log(thisForm);
        var myInputs = thisForm.getElementsByTagName('Input');
        for (var j=0; j < myInputs.length; j++) {
	      if (myInputs[j].name === 'fname') myInputs[j].value = "Matt";
	      if (myInputs[j].name === 'lname') myInputs[j].value = "Brown";
	      if (myInputs[j].type === 'email')	myInputs[j].value = "admin@";
        }
}

Unfortunately, starting sometime this last spring, Squarespace's javascript code related to forms will delete any pre-filled data as soon as a user enters any characters into any of the form items in the same form.

You can see an example of this here:
https://www.crescentproject.org/test3

I have tried listening for changes to the form items and re-filling them but they are deleted again by Squarespace's javascript and looks really odd from a user point of view.

Squarespace support was able to reproduce the issue (which was appreciated) but then asserts that it is a user code issue, so not their problem.

Does anyone have suggestions for a work-around or how to address this with Squarespace so they will fix their bug?

Thanks
Matt

Update - the issue is getting forwarded on to engineering to have a look at.

Still - it would be great to have a work-around if there are any suggestions.

1 hour ago, MattBrown said:

starting sometime this last spring, Squarespace's javascript code related to forms will delete any pre-filled data. Does anyone have suggestions for a work-around or how to address this with Squarespace so they will fix their bug?

This isn’t a bug. In May, Squarespace replaced the form block with a new React based form and this means you cannot set the value in this way. React won’t be aware of the change (it is only a change to the DOM). 

Thanks, that's helpful