Can onFocus be counted on prior to form data change?


I’m curious if their are instances where a user might change form data without first focusing on the form element. For instance, can it be counted on that an input field will be focused (onFocus) prior to its value being changed?

I know that it can’t be counted on to be secure, but for general use by everyday users, can one assume an element’s onFocus event will be triggered prior to the user changing form data? If not, in what scenarios isn’t this the case?


I thought of one…extensions that automatically fill out forms. This could be corrected for with onChange.

Can you think of any other instances where this might be the case?