observe_field inserted select not submitting

[adamp]

I'm trying to set up a form that among other things includes two related select drop-downs, where the choice the user makes for the first select will then re-load the second select list with the relevant options.

The problem I'm having is that by re-inserting the select using observe_field, the inserted select's value never gets sent with the rest of the form data. Is this a known problem and is there a way around it?

My edituser.rhtml

<h2>Edit user <%= @user.firstname + ' ' + @user.lastname %></h2>
 
 
 <h3><%= @user.firstname %>'s permissions</h3>
 
 <%= form_tag :action => 'addpermission' %>
 <table id="permissions">
 	<thead>
 		<tr>
 			<th>Controller</th>
 			<th>Action</th>
 			<th>ID</th>
 			<th>Allow/Disallow</th>
 			<th>Moderate</th>
 		</tr>
 	</thead>
 	<tbody>
 <% for permission in @user.permissions %>
 		<tr>
 			<td><%= link_to permission.controller, :controller => permission.controller %></td>
 			<td><%= (permission.action == '') ? link_to('All', :controller => permission.controller) : link_to(permission.action, :controller => permission.controller, :action => permission.action) %></td>
 			<td><%= (permission.target_id == 0) ? 'All' : permission.target_id %></td>
 			<td>
 				<%= (permission.allow == 1) ? 'Allowed' : '' %>
 				<%= (permission.disallow == 1) ? 'Disallowed' : '' %>
 			</td>
 			<td><%= (permission.moderated == 1) ? 'Yes' : 'No' %></td>
 		</tr>
 <% end %>
 		<tr>
 			<td colspan="5">
 				<h4>Add a permission</h4>
 				<%= hidden_field 'permission', 'user_id', :value => params[:id] %>
 			</td>
 		</tr>
 		<tr>
 			<td><%= select 'permission', 'controller', @cs %></td>
 			<td id="actionlist">
 				<%= select 'permission', 'action', [ ['Choose a controller first', 'debug'] ]%>
 			</td>
 			<td><%= text_field 'permission', 'target_id', :size => 4 %></td>
 			<td><%= select 'other', 'allowdisallow', %w{ Allow Disallow } %></td>
 			<td><%= select 'permission', 'moderated', [ ['No', 0], ['Yes', 1] ] %></td>
 		</tr>
 		<tr>
 			<td colspan="5">
 				<%= submit_tag 'Create permission' %>
 			</td>
 		</tr>
 	</tbody>
 </table>
 <%= end_form_tag%>
 <%= observe_field("permission_controller",
 	:frequency => 0.5,
 	:update => "actionlist",
 	:url => { :action => 'controller_action_list' },
 	:with => "'ctrl='+value") %>

The two selects in question being permission_controller and permission_action. The observe_field submits to controller_action_list to create the new select:

controller_action_list:

	def controller_action_list
 		if @params['ctrl'] != 'Please choose a controller'
 			# turn back into class name
 			ctrl = params['ctrl'].sub(/[a-z]/) {|match| match.upcase}
 			ctrl = ctrl.gsub(/_([a-z])/) {|match| match.upcase.sub(/_/, '')}
 			ctrl += "Controller"
 			
 			@c = Object.const_get(ctrl).new
 
 		end
 		
 		render(:layout => false)
 	end

And controller_action_list.rhtml

<% if @params['ctrl'] != 'Please choose a controller' %>
 <select name="permission[action]" id="permission_action">"
 	<option value="">All <%= @c.controller_name %> actions</option>
 	<% for m in @c.public_methods(false) %>
 	<option value="<%= m %>"><%= m %></option>
 	<% end %>
 </select>
 <% else %>
 <select name="permission[action]" id="permission_action">
 	<option value="">Choose a controller first</option>
 </select>
 <% end %>

If the form is submitted without the observe_field being triggered, then the permissions[action] value is sent fine. Once the select has been re-written that form attribute simply never gets sent.

[adamp]

No-one? :/

[alistair_b]

<%= observe_field("permission_controller",
 	#:frequency => 0.5,
 	:update => "actionlist",
 	:url => { :action => 'controller_action_list' },
 	:with => "ctrl") %>

try it like that it should produce ctrl=#{value} on calls

[adamp]

Sorry, I might not have explained the problem properly. I can update the second list fine (actually replaces it), so you can then choose your option in the second list, but then when you submit the form, the value of the second (AJAX-created) list is not posted.

It seems that the second select is being pulled out of the context of the form when it's replaced, even though it's put back in the same place, inside the form.