title: How to define a select field in a nested form?
body: <p>What is the correct way to include a select field within a nested form in Rails 3.2?</p>
  
  <p>I currently have</p>
  
  <pre><code>//IN THE PARENT FORM
  
  &lt;%= f.fields_for :crayons  do |crayon| %&gt;
     &lt;%= render 'caryon_fields', :f=&gt;crayon %&gt;
  &lt;% end %&gt;
  
  //IN THE PARTIAL
  
  &lt;div class="nested-fields"&gt;
     &lt;%= select (:crayon, :color, [['Red',1],['Blue',2],['Yellow',3],['Green',4]] ) %&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>This is not saving the selected value to the database. I assume this is because the builder  is not being passed.</p>
  
  <p>How should I define a select field with hardcoded options in a nested field? Do I need to change tag, i.e. <code>select_tag</code> or <code>collection_select</code>. I'm still unsure of the differences between all these. If anyone can point me towards a clear description it would be much appreciated.</p>
  
  <p>Thanks!</p>