Nested attributes don't afford me access to associated model data

Question

Im looking for the proper way to build a form for the following data structure:

class Profile < ActiveRecord::Base
  attr_accessible :name
  has_many :weights
  accepts_nested_attributes_for :weights
end

class Tag < ActiveRecord::Base
  attr_accessible :name
  has_many :weights
end

class Weight < ActiveRecord::Base
  attr_accessible :weight, :profile_id, :tag_id
  belongs_to :profile
  belongs_to :tag
end

In the edit profile form I want to pull in all the weights and allow users to update them. I've been able to do this with nested attributes like so:

<%= form_for [:admin, @profile] do |f| %>
  <%= f.error_messages %>
  <p>
    <%= f.label :name %>
    <%= f.text_field :name %>
  </p>
  <div class='weights'>
    <%= f.fields_for :weights do |ff| %>
      <%= ff.label :weight %>
      <%= ff.text_field :weight %>
    <% end %> 
  </div>

  <%= f.submit %> 
<% end %>

The thing is that I actually want to pull in the title of the associated tag_id on each weights row as well (so people know which weight's tag they are changing). I don't see a way to pull this info in, should I be doing some sort of join before I write this form out? Is this a silly approach?

Thanks everyone

-Neil

Answer 1

You should be able to get at the weight through ff.object and tag through ff.object.tag.title. Have you tried this?