Rails - Oct 2005 - Simple AJAX/javascript helpers problem (I think)

Hi all,

Sorry to repeat a question that might be stupid, but I could really use 
some help with this.

Does anybody know if there is a way to get observe_field to work with 
hidden_field? I have a series of drop-down <select> menus that guide 
the user through a narrowing series of options; each of these 
drop-downs relies upon observe_field to generate the next one an option 
is chosen. On some occasions, there may be only one option available, 
in which case there should not be a <select> drop-down but the name of 
the option is delivered inline, the value placed in a hidden form 
element, and the next drop-down should be generated. But observe_field 
doesn''t seem to work on a hidden field. Something like 
periodically_call_remote would work, except that (1) if needs to take a 
value to the controller, and (2) it should only happen once.

This is what the view is looking like at the moment; observe_field, as 
noted, does not work with the results of the <else> branch.

<% if @departments.length > 1 %>
   <%= select("article", "department_id",
@departments.collect {|d|
[d.department_name, d.id] }) %>
<% else %>
   <%= h(@departments.first.department_name) %>
   <%= hidden_field("article", "department_id") %>
<% end %>
<%= observe_field("article_department_id",
     :frequency => 0.25,
     :update => "article_type",
     :url => { :action => "add_article_type" },
     :with => "''department_id=''+value") %>

My sleep deprivation thanks anyone who can help,

Rob

Robert Wheaton wrote:
> Does anybody know if there is a way to get observe_field to work with 
> hidden_field? I have a series of drop-down <select> menus that guide
the
> user through a narrowing series of options; each of these drop-downs 
> relies upon observe_field to generate the next one an option is chosen. 
> On some occasions, there may be only one option available, in which case 
> there should not be a <select> drop-down but the name of the option
is
> delivered inline, the value placed in a hidden form element, and the 
> next drop-down should be generated. But observe_field doesn''t seem
to
> work on a hidden field. Something like periodically_call_remote would 
> work, except that (1) if needs to take a value to the controller, and 
> (2) it should only happen once.
If there is only one choice, return and render both the hidden field
and the next select, with the observe_field acting only on the latter.

-- 
We develop, watch us RoR, in numbers too big to ignore.