title: Render a Collection of Text Fields which is passed to Doctrine array field
body: <p>In my entity i have an array field:</p>
  
  <pre><code>/**
   * @var array
   *
   * @ORM\Column(name="work_experience", type="array")
   */
  private $workExperience;
  </code></pre>
  
  <p>now i want to render a collection of text fields which will be passed to this array field.</p>
  
  <pre><code>-&gt;add('workExperience', 'collection', array(
                  'type'         =&gt; 'text',
                  'allow_add'    =&gt; true,
                  'allow_delete' =&gt; true,
                  'prototype'    =&gt; true,
                  #'by_reference' =&gt; false,
                  'options'  =&gt; array(
                      'required'  =&gt; false,
                      'attr'      =&gt; array('class' =&gt; 'line-box')
                  ),
              ))
  </code></pre>
  
  <p>but now when i render this field, no input is shown? What is my mistake?</p>
  
  <pre><code>{{ form_row(form.workExperience) }}
  </code></pre>
  
  <p>Thank you</p>