是否有明显的方法来区分Symfony中的字符串/数组/实体/对象（例如）？

Question

我试图找到Symfony的脚，并且在幕后继承了许多Symfony类，我很难知道我有时会处理什么。我发现我经常磕磕碰碰地知道$variables是否是字符串/数组/实体/对象。

有人可以提供一些规则或指导，以了解正在处理哪些内容以及如何处理$variable？

例如，在最后的FormType类中，我发现很难看到正在播放的字符串/数组/实体/对象。

我的尝试是：

UserType class (child of AbstractType)

   // function buildForm
   ˪$builder object (instantiated by FormBuilderInterface)
      ˪$options array
      ˪$Firstname string
      ˪$owner object (instantiated by AppBundle:Owner entity)
         ˪class array element
         ˪choice_label array element
         ˪query_builder array element
            ˪$er object (instantiated by EntityRepository)
               ˪array $o (contains elements for database query result)
      ˪$onPreSetData object (instantiated by FormEvents::PRE_SET_DATA)
      ˪$onPreSubmit  object (instantiated by FormEvents::PRE_SUBMIT)

      // function addElements
      ˪$form object (instantiated by FormInterface)
         ˪$post object (instantiated by AppBundle:Post entity)
            ˪class array element
            ˪choice_label array element
            ˪query_builder array element
               ˪$er object (instantiated by EntityRepository)
                  ˪array $o (contains elements for database query result)

      // function onPostSubmit (similar for onPreSubmit)
      ˪$event object (instantiated by FormEvent)
         ˪$form object (instantiated from '$this' object)
         ˪$data object (instantiated from '$this' object)

代码我指的是：

use Doctrine\ORM\EntityRepository;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\Form\FormEvents;
use Symfony\Component\Form\FormEvent;
use Symfony\Component\OptionsResolver\OptionsResolver;


class UserType extends AbstractType
{
  public function buildForm(FormBuilderInterface $builder, array $options)
  {
        $builder
             ->add('Firstname')
             ->add('owner','entity',array(
                  'class'=>'AppBundle:Owner',
                  'choice_label'=>'username',
                  'query_builder'=>function(EntityRepository $er) {
                        return $er->createQueryBuilder('o')
                             ->orderBy('o.username','ASC');
                  }));

        // Add listeners for Post field
        $builder->addEventListener(FormEvents::PRE_SET_DATA, array($this, 'onPreSetData'));
        $builder->addEventListener(FormEvents::PRE_SUBMIT, array($this, 'onPreSubmit'));
  }


  protected function addElements(FormInterface $form, $owner = null)
  {
        if($owner){
             $form->add('post','entity',array(
                  'class'=>'AppBundle:Post',
                  'choice_label'=>'posttext',
                  'query_builder'=>function(EntityRepository $er) {
                        return $er->createQueryBuilder('p')
                             ->join('p.owner', 'o')
                             ->where('o.id = :ownerID')
                             ->setParameter('ownerID', $owner->getID() )
                             ->orderBy('d.postdate','ASC');
                  }));
        }
  }

  public function onPreSubmit(FormEvent $event)
  {
        $form = $event->getForm();
        $data = $event->getData();

        $this->addElements($form, $data->getOwner());
  }

  public function onPreSetData(FormEvent $event)
  {
        /** @var User user */
        $user = $event->getData();
        $form = $event->getForm();

        $this->addElements($form, $user->getOwner());
  }
}