title: Rails button_to: how to specify the controller?
body: <p>I don't understand what's happening here. I want to put a <code>button_to</code> in my (haml) view. If I do this:</p>
  
  <pre><code>=button_to( "New", {:action =&gt; "new"}, {} )
  </code></pre>
  
  <p>the page generated has:</p>
  
  <pre><code>&lt;form action="/cached_input_files/new" class="button_to" method="post"&gt;
    &lt;div&gt;
      &lt;input type="submit" value="New" /&gt;
      &lt;input name="authenticity_token" type="hidden" value="..blah.." /&gt;
    &lt;/div&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>which is OK, but I need to address a different controller. But if I try to specify the controller:</p>
  
  <pre><code>=button_to( "New", {:action =&gt; "new", :controller =&gt; "editor"}, {} )
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>&lt;form action="/assets?action=new&amp;controller=editor" class="button_to" method="post"&gt;
    &lt;div&gt;
      &lt;input type="submit" value="New" /&gt;
      ...
  </code></pre>
  
  <p>I expected the <code>action</code> to be <code>"/editor/new"</code>, and I have no idea why it isn't, nor how to correctly specify the controller I want to route to.</p>
  
  <p>I'm using Rails 3.2.1.</p>