title: capture_haml in helper not displaying parameter values
body: <p>I'm trying to use a helper in my rails view to draw some haml lines, the fact is that it is writing the html tags, but no content in them.</p>
  
  <p>Here's my helper:</p>
  
  <pre><code>def detail_line(model, column, value)
    capture_haml do  
      haml_tag :div, class: 'control-group' do
        haml_tag :label, {class: 'control-label'},"#{model.class.human_attribute_name column}"
        haml_tag :div, class: 'controls' do
          haml_tag :div, {class: 'value'}, "#{value}"
        end
      end
    end
  end
  </code></pre>
  
  <p>And here's the way I'm using it:</p>
  
  <pre><code>= detail_line(@order, 'number', @order.number)
  </code></pre>
  
  <p>The output is the following:</p>
  
  <pre><code>&lt;div class="control-group"&gt;
    &lt;label class="control-label"&gt;&lt;/label&gt;
    &lt;div class="controls"&gt;
       &lt;div class="value"&gt;&lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>What am I missing or doing wrong?
  Thank you very much in advance!</p>