Observe_form without ajax?

Rails
1

This betrays my lack of javascript knowledge, but is it possible to
watch a whole form for changes and activate some javascript when those
changes occur without any remote request?

That is, I want to do exactly what observe_form does, but without the
ajax call actually happening. I realize I could use the form_tag
:onchange parameter, but that seems to be incapable of doing things like
updating a DOM element style.

Currently I just put my javascript in :complete and have the ajax render
:nothing => true, but that’s a hack and uses unnecessary bandwidth.

-Payton

2

Although in danger of answering my own question, I just discovered how
to work prototype’s Form.Observer. It appears to do the trick, although
it means I have to encapsulate my javascript in a separate function in
order to use the callback feature.

Sorry to trouble you all.

-Payton

3

If you are running EdgeRails or the new Rails 1.1.0 RC1 release
candidate then you can do this in your view:

<%= observe_form ‘form_id’, :frequency => 2, :function => “alert
(‘Form changed’)” %>

The :function option can be any javascript that you want to execute.

-Jonathan