I’m moving an old app to Rails 2.0 and other than fixing some routes Ajax calls with link_to_remote and the :with parameter was the only thing that gave me some trouble. In the old version I was grabbing the current value of a drop down list with Prototype and passing it along using :with like this

<%= link_to_remote image_tag(‘cms/add_16.gif‘, :id => “color_add“),
      :url => { :controller => “colors“, :action => “new_ajax“,
      :id => @product.id },
      :with => “{ color_id: $F(’color_id’) }“
%>

But in Rails 2.0 the parameter wouldn’t go along for the ride, it seemed that the new authenticity_token that gets sent with Ajax calls was messing things up. Here’s the fix

<%= link_to_remote image_tag(‘cms/add_16.gif‘, :id => “color_add“),
      :url => { :controller => “colors“, :action => “new_ajax“,
      :id => @product.id },
      :with => “‘color_id=’+$F(’color_id’)“
%>

I freely admit JavaScript/Ajax is my weakest language so if I was doing it wrong the entire time let me know :)