title: Symfony form type choice field boolean always true
body: <p>I have entity with property reverse, type boolean and form for this property type choice - checkbox and always after form handleRequest I have <code>true</code> why not understand, if check box not checked have <code>"0"</code> but after submit form have <code>true</code></p>
  
  <pre><code>    /**
   * @var boolean
   *
   * @ORM\Column(name="reversed_vat", type="boolean", nullable=false, options={"default"=0})
   */
  private $reversedVat;
  
    /**
   * Set reversedVat
   *
   * @param boolean $reversedVat
   *
   * @return OutboundInvoice
   */
  public function setReversedVat($reversedVat)
  {
      $this-&gt;reversedVat = (boolean)$reversedVat;
  
      return $this;
  }
  </code></pre>
  
  <p>In form I create data transformer with check property but in transfomer I have true</p>
  
  <pre><code>/**
   * Get reversedVat
   *
   * @return boolean
   */
  public function getReversedVat()
  {
      return (boolean)$this-&gt;reversedVat;
  }
  
      $builder
          -&gt;add('reversedVat', CheckboxType::class, ['required' =&gt; false])
  
          $builder-&gt;get('reversedVat')
          -&gt;addModelTransformer(new CallbackTransformer(
              function($mypropertyAsBoolean) {
  
              },
              function($mypropertyAsString) {
                  $r = $mypropertyAsString;//have always true
              }
          ));
  </code></pre>
  
  <p>if I not checked still have true after form handleRequest  ?</p>