Show warning for unsaved changes when leaving page

[JuliDi]

Is your feature request related to a problem? Please describe.
When I make changes to a user in the Admin UI and forget to click save before leaving the page, all changes are lost.

Describe the solution you'd like
Show a warning about unsaved changes when trying to leave the page.

Describe alternatives you've considered
Save automatically when leaving the input, but I personally don't like it if applications do that.

Additional context
n/a

[sebadob]

That's not that easy and quickly done as you might think. Tracking changes is possible in a few lines of code, but preventing from clicking anywhere else and stopping that action can be very tricky, especially in a more complex UI setup like Rauthys.

A visual indicator that lights up maybe as a border or something like that is pretty quickly done, but preventing the action is quite a big amount of work if done properly.

Save automatically when leaving the input, but I personally don't like it if applications do that.

Yeah, it depends. In some cases i really like that, in others it can be an issue pretty quickly, especially when it's security sensitive stuff.

[JuliDi]

Isn't there any browser-support within forms?

As for change detection: it might already be very helpful to gray-out the "save" button as long as no changes have been made.
A border might be even better, but presumably also more difficult to implement...

[sebadob]

Not sure about browser support for this, but the user page does not use traditional form submit, but actually builds the payload on submit via JS. It uses PATCH requests and only updates values that have been changed anyway already, so detecting these is basically done already, kind of.

Just showing it on the Save button would not be enough, because you usually need to scroll down to see it. I was more thinking of something like a left border for the whole user values <div>, or something else that you would see in any scroll position.