Exclude certain values in ManytoOne Array Colletion/Formbuilder - symfony

Question

I am having trouble getting a formular in Symfony2 where I want to exclude certain values within an array collection - or I have to say I don't know how (where to exclude them).
This is my newTag Action:
public function newTagAction()
{
$tag = new Tag();
$form = $this->createForm(new tagType(), $tag);
return $this->render('MyMyBundle:Admin:newTag.html.twig', array('form' => $form->createView()));
}
And Tag.php Entity, which has a ManyToOne relation to Movie and vice verca (Movie->Tag = OneToMany):
class Tag
{
/**
* #ORM\Id
* #ORM\Column(type="integer")
* #ORM\GeneratedValue(strategy="AUTO")
*/
protected $id;
/**
* #ORM\Column(type="string")
*/
protected $name;
/**
* #ORM\ManyToOne(targetEntity="Movie", inversedBy="videotags")
* #ORM\JoinColumn(name="movie_id", referencedColumnName="id")
*/
protected $movie;
// ...
In the TagType.php form it says:
class TagType extends AbstractType
{
public function buildForm(FormBuilder $builder, array $options)
{
$builder
->add('name')
->add('movie') // This is where certain movies should be excluded, it displays an array collection of all movies
;
}
Any help appreciated!
Thanks!

Answer 1

You can use custom queries to get only the results you want.
It's explained in the documents. Here is a quick example:
$builder->add('movie', 'entity', array(
'class' => 'MyMovieBundle:Movie',
'query_builder' => function(EntityRepository $er) {
return $er->createQueryBuilder('u')
->where('u.name = ?1');
},
));