Google Apps Script - Run javascript as the form is being filled by users

Question

I am new to Google apps script and need help. I an trying to achieve the following -

Set a trigger for lost-focus of a textbox in google form. The code in this event will be A. Get the value of a textbox B. Set the value of a textbox

Answer 1

Unfortunately this is not currently possible with Google Apps Script and Google Forms. Apps Script can be triggered by the submission of a Form, but it cannot interact with the Form in the users browser.

It is possible to build a form entirely in Apps Script (using HTML) which would allow you full control over the user experience, but you lose access to the functionality provided by Google Forms.