title: Why doesn't my nested form display?
body: <p>Running on Rails 3.1 RC1 and following <a href="http://railscasts.com/episodes/196-nested-model-form-part-1" rel="nofollow">this</a>.</p>
  
  <p>A user can have one or many emails. My email fields don't show in the form. No error is rendered. </p>
  
  <p>The form element is displayed. But no input fields. Nada. Am I missing something? </p>
  
  <p>Controller:</p>
  
  <pre><code>def new
    @user = current_user
  
    #1.times do
      email = @user.emails.build
    #end
  ....
  end
  </code></pre>
  
  <p>User model:</p>
  
  <pre><code>class User &lt; ActiveRecord::Base
    has_many :emails, :dependent =&gt; :destroy
    accepts_nested_attributes_for :emails
  ....
  end
  </code></pre>
  
  <p>Email model:</p>
  
  <pre><code>class Email &lt; ActiveRecord::Base
    belongs_to :user
  end
  </code></pre>
  
  <p>Form:</p>
  
  <pre><code>&lt;%= form_for(@user, :url =&gt; users_path, :html =&gt; { :method =&gt; :post }) do |f| %&gt;
  
      &lt;ul&gt;
  
        &lt;li class="clearfix"&gt;
          &lt;%= f.fields_for :emails do |builder| %&gt;
            &lt;%= builder.label :email %&gt;
            &lt;%= builder.text_field :email %&gt;
            &lt;span&gt;Note: Your email will not be publicly displayed&lt;/span&gt;
          &lt;% end %&gt;
        &lt;/li&gt;
  ....
  </code></pre>