title: Symfony 2.6 - render individual choice field (radio, checkbox) by name
body: <p>How can I render an individual field (single radio/checkbox input field) in Twig in Symfony 2.6?</p>
  
  <p>Let's say I have a simple form:</p>
  
  <pre><code>class TransportType extends AbstractType
  {
      public function buildForm(FormBuilderInterface $builder, array $options)
      {
              $builder-&gt;add('transport', 'choice', array(
                  'choices' =&gt; array(
                      'road' =&gt; 'Car/bus',
                      'train' =&gt; 'Train',
                  ),
                  'expanded' =&gt; true,
                  'multiple' =&gt; false
              ));
      }
  </code></pre>
  
  <p>In previous Symfony2 versions I could just use:</p>
  
  <pre><code>{{ form_widget(form.transport.road) }}
  {{ form_widget(form.transport.train) }}
  </code></pre>
  
  <p>to render individual radio buttons, but it doesn't seem to work anymore. I know I can use:</p>
  
  <pre><code>{{ form_widget(form.transport[0]) }}
  {{ form_widget(form.transport[1]) }}
  </code></pre>
  
  <p>but it's less flexible. Of course I can iterate over the collection and check for name, but this seems like unnecessary hassle. Isn't there an easier way?</p>
  
  <p>I tried <code>offsetGet</code> (which is supposed to <code>return a child by name</code>), but it also works only with array index.</p>