Validate the registration form immediately when typing

[deevroman]

Description

1. It is difficult to choose a free login. Most likely you won't be able to do it on the first try. And not even with the second one. To check this, you need to submit a form.

2. Any mistake in the form erases the password. And it needs to be entered at least twice! Nothing prevents you from checking all the fields automatically before sending, so that the user immediately knows that everything is filled out correctly.

Screenshots

[gravitystorm]

I think it would be nice to check the display name (and password format, which has been asked for before) before form submission, but I'm reluctant to create too much home-grown javascript to add this functionality.

What I would prefer is to first move to Turbo/Stimulus, so that we can get some more idiomatic approaches to interactivity, and that approach will be better in the long run.