How to get underlying object in Sonata's Admin class when called by sonata_type_admin?

Question

So, in edit action of Sonata Admin I'm trying to display different form fields depending on create or edit context.

Maybe some background first..

I have a Gallery entity and a CoverPhoto entity bound with OneToOne.

Gallery:

/**
 * @ORM\OneToOne(targetEntity="CoverImage", mappedBy="gallery", cascade={"all"}, orphanRemoval=true)
 **/
private $cover;

CoverImage:

/**
 * @ORM\OneToOne(targetEntity="Gallery", inversedBy="cover")
 **/
private $gallery; 

Here's coresponding GalleryAdmin class:

class GalleriesAdmin extends Admin
{
    protected function configureFormFields(FormMapper $formMapper)
    {
        $formMapper
                -> add('name', null, array('label' => 'Nazwa'))
                -> add('category', 'sonata_type_model', array('label' => 'Kategoria'), array('subject' => $this -> getSubject()))
                -> add('cover', 'sonata_type_admin', array('label' => 'Okładka'))
                -> add('images', 'sonata_type_collection', array('by_reference' => false, 'label' => 'Powiązane zdjęcia'), array(
                    'edit' => 'inline',
                    'sortable' => false,
                    'inline' => 'table',
                ))
            ;
    }

    //other stuff 
}

And here we go with CoverImageAdmin:

class CoverImagesAdmin extends Admin
{
    protected function configureFormFields(FormMapper $formMapper)
    {
        $formMapper
                -> add('path', 'thumbnail', array('label' => 'Miniatura'))
                -> add('file', 'file', array('required' => false, 'label' => 'Plik'))
        ;
    }
}

"Thumbnail" is my custom form field which displays thumbnail (shocker). But now i want this field only appear in "edit" context.

This should be piece of cake with

$this -> getSubject()

method of Admin class and condition. Unfortunately when I call getSubject() in CoverImagesAdmin class which is used to render nested form it always returns null. The same with getParent();

Calling getForm() results in

Fatal error: Maximum function nesting level of '500' reached, aborting! in /home/flameheart/Projects/KolberPhotography/vendor/symfony/symfony/src/Symfony/Component /OptionsResolver/Options.php on line 350

I've tried to call about every method of Admin and FormMapper just to determine form's context but ended up with nothing.

Do you guys have any idea how to solve this in a clean way ?

Answer 1

I managed to do it this way:

protected function configureFormFields(FormMapper $formMapper)
{

    if($this -> getRoot() -> getSubject() -> getCover() && $this -> getRoot() -> getSubject() -> getCover() -> getId() )
    {
        $formMapper -> add('path', 'thumbnail', array('label' => 'Miniatura', 'attr' => array('id' => 'gallery_cover_image'), 'label_attr' => array('id' => 'gallery_cover_label')));
    }

    $formMapper -> add('file', 'file', array('required' => false, 'label' => 'Plik'));
}

Imo, this Sonata thing really needs loads of documentation and refactoring instead of further development.