Rails 2 and ajax - few select lists - ruby-on-rails

Question

I can't figure what i do wrong. I have few select lists:
Regions
Towns
Organizations
How it should works:
User selects region.
List of towns loads.
User selects town.
List of organizations loads.
User chooses organization.
I use ajax for that and i realized only auto-loading for list of towns and i can't do same thing for organization. Second select list DOESN'T POST at all!
Here is my code:
View
%div
%br/
= select 'ajax', :region_id, [['Choose your region...', -1]] + Region.all.map{|region| [region.name, region.id]}.sort
= image_tag('ajax-loader.gif', :id => 'ajax-progress', :style => 'display: none;')
= observe_field :ajax_region_id, :url => { :controller => :organizations, :action => :list_towns, :preselect => (defined?(preselect) && !preselect.nil?) }, :with => 'region_id', :update => 'select_organization_idd', :loading => '$("ajax-progress").show();', :complete => 'if (Ajax.activeRequestCount == 1) $("ajax-progress").hide();'
%br/
= select 'ajax2', :o_id, [], {}, {:id => 'select_organization_idd', :style => 'width: 60em;'}
= image_tag('ajax-loader.gif', :id => 'ajax-progress', :style => 'display: none;')
= observe_field :ajax_region2_id, :url => { :controller => :organizations, :action => :list_region, :preselect => (defined?(preselect) && !preselect.nil?) }, :with => 'o_id', :update => 'select_organization_idd2', :loading => '$("ajax-progress").show();', :complete => 'if (Ajax.activeRequestCount == 1) $("ajax-progress").hide();'
= f.select :organization_id, [], {}, {:id => 'select_organization_idd2', :style => 'width: 60em;'}
Controller
def list_region
render :text => ActionController::Base.helpers.options_for_select((params[:preselect] ? [['Choose organization', -1]] : []) + Organization.map{|org| [ActionController::Base.helpers.truncate(org.name, :length => 155), org.id]})
end
def list_towns
region = Region.find(params[:region_id])
towns = Kladr.find(:all, :conditions => ['code LIKE ?', "#{region.code}%"])
render :text => ActionController::Base.helpers.options_for_select([['Choose town', -1]] + towns.map{ |t| ["#{t.socr}. #{t.name}", t.id] })
end
What do i do wrong? Also i use Rails 2, that why observe_field is not deprecated.

Answer 1

Do you use rails 3? The method observe_field is deprecated.
With rails 3 you must do something like this :
view
%div
%br/
= select 'ajax', :region_id, [['Choose your region...', -1]] + Region.all.map{|region| [region.name, region.id]}.sort, {}, {:id => 'ajax1'}
= image_tag('ajax-loader.gif', :id => 'ajax-progress', :style => 'display: none;')
%br/
= select 'ajax2', :o_id, [], {}, {:id => 'select_organization_idd', :style => 'width: 60em;'}, {}, {:id => 'ajax2'}
= image_tag('ajax-loader.gif', :id => 'ajax-progress', :style => 'display: none;')
= f.select :organization_id, [], {}, {:id => 'select_organization_idd2', :style => 'width: 60em;'}
javascript.js.coffee
$('#ajax1').change = () ->
$.post(
url: '/organizations/list_towns'
data: {value: $('#ajax1').val()}
success: () ->
if (Ajax.activeRequestCount == 1)
$("ajax-progress").hide()
)
$('#ajax2').change = () ->
$.post(
url: '/organizations/list_regions'
data: {value: $('#ajax2').val()}
success: () ->
if (Ajax.activeRequestCount == 1)
$("ajax-progress").hide()
)
The implementation is probably wrong and could be refactored. I didn't test it. But you've got the idea.