title: Error using 'path' for collection: in simple_form_for
body: <p>I am using simple_form_for. In that I want a drop down with few values. These values are returned from a method in the controller which returns a hash of those values.</p>
  
  <p>In the view I have:</p>
  
  <pre><code>= f.input :address_id, collection: address_string_gift_cards_path
  </code></pre>
  
  <p>The controller method is:</p>
  
  <pre><code>def address_string
    #Some code here that returns hash of values
  end
  </code></pre>
  
  <p>In my routes file I have:</p>
  
  <pre><code>resources :gift_cards do
      collection do
        get :address_string
      end
    end
  </code></pre>
  
  <p>In the output I am getting error:</p>
  
  <pre><code>undefined method `to_a' for "/gift_cards/address_string":String
  </code></pre>
  
  <p>I dont know what mistake I am making. Any help would be much appreciated. Thanks in advance:)</p>