In rails controllers, how to prevent double submit (when user double-clic submit button or hit enter twice)?

Question

Well, everything\'s in the title but I\'ll explain a little more :-)

My rails app contain many forms (Ajaxified or not).

To prevent users to submit twice or more

Answer 1

1) It's nice to also show some moving indicator to let user know that something's going on, that their request is being processed. It should eliminate lots of double submits.

2) If user has disabled javascript, how're you gonna submit 'ajaxified' forms? If site becomes not functional without javascript, then it's probably best to just notify user (like Eimantas suggests).

edit One example of such indicator, just to be clear what I mean in 1.
http://www.netzgesta.de/busy/