How Do I Prevent Rails From Treating Edit Fields_For Differently From New Fields_For

Question

I am using rails3 beta3 and couchdb via couchrest. I am not using active record.

I want to add multiple "Sections" to a "Guide" and add and remove sections dynamically via a little javascript. I have looked at all the screencasts by Ryan Bates and they have helped immensely. The only difference is that I want to save all the sections as an array of sections instead of individual sections. Basically like this:

"sections" => [{"title" => "Foo1", "content" => "Bar1"}, {"title" => "Foo2", "content" => "Bar2"}]

So, basically I need the params hash to look like that when the form is submitted. When I create my form I am doing the following:

<%= form_for @guide, :url => { :action => "create" } do |f| %>
  <%= render :partial => 'section', :collection => @guide.sections %>   
  <%= f.submit "Save" %>
<% end %>

And my section partial looks like this:

<%= fields_for "sections[]", section do |guide_section_form| %>
  <%= guide_section_form.text_field :section_title %>
  <%= guide_section_form.text_area :content, :rows => 3 %>
<% end %>

Ok, so when I create the guide with sections, it is working perfectly as I would like. The params hash is giving me a sections array just like I would want. The problem comes when I want edit guide/sections and save them again because rails is inserting the id of the guide in the id and name of each form field, which is screwing up the params hash on form submission.

Just to be clear, here is the raw form output for a new resource:

<input type="text" size="30" name="sections[][section_title]" id="sections__section_title">
<textarea rows="3" name="sections[][content]" id="sections__content" cols="40"></textarea>

And here is what it looks like when editing an existing resource:

<input type="text" value="Foo1" size="30" name="sections[cd2f2759895b5ae6cb7946def0b321f1][section_title]" id="sections_cd2f2759895b5ae6cb7946def0b321f1_section_title">
<textarea rows="3" name="sections[cd2f2759895b5ae6cb7946def0b321f1][content]" id="sections_cd2f2759895b5ae6cb7946def0b321f1_content" cols="40">Bar1</textarea>

How do I force rails to always use the new resource behavior and not automatically add the id to the name and value. Do I have to create a custom form builder? Is there some other trick I can do to prevent rails from putting the id of the guide in there? I have tried a bunch of stuff and nothing is working.

Thanks in advance!

Answer 1

Ok, I think I have figured out something that works. Changing the first line of the partial to:

<%= fields_for "sections", section, :index => "" do |guide_section_form| %>

Seems to work just fine. This way both new and edit form looks the same under the hood and the params hash works just like I need it to. If anyone sees anything wrong with this or has another alternative, please let me know.