sonata admin one to many and many to many form - symfony

Question

I have OneToMany related entities Gallery and Media stored in galleries_media
and I have Many To One related and Many To One related in GalleryMedia Entitiy
/**
* #var ArrayCollection
*
* #ORM\OneToMany(targetEntity="\Entity\GalleryMedia", mappedBy="gallery", cascade={"persist", "remove"})
*/
protected $galleriesMedia;
and in GalleryMedia Entitiy
/**
* #ORM\ManyToOne(targetEntity="\Entity\Gallery", inversedBy="galleriesMedia")
* #ORM\JoinColumn(name="gallery_id", referencedColumnName="id", nullable=false)
*/
protected $gllary;
/**
* #ORM\ManyToOne(targetEntity="\Entity\Media", inversedBy="galleries")
* #ORM\JoinColumn(name="media_id", referencedColumnName="id", nullable=false)
*/
protected $media;
how i do this in form

Answer 1

One-To-Many : sonata_type_collection
In your case:
class GalleryAdmin
{
// ...
$formMapper
->add('galleriesMedia', 'sonata_type_collection', [
'required' => false,
'label' => 'my_galleries_media_label',
'btn_add' => 'my_add_button_name',
'type_options' => [
'delete' => false,
],
], [
'edit' => 'inline', // or standard
'inline' => 'table', // or standard
'sortable' => 'id', // by any field in your entity
'limit' => 5, // you can remove this - this is a limit of items
'allow_delete' => false,
'placeholder' => $this->trans('admin.placeholder.no_media'),
])
;
class GalleriesMediaAdmin
{
// ...
$formMapper
->add('media', 'sonata_type_model_list', [
'required' => true,
'btn_add' => false,
'btn_list' => 'name_of_list_button'
'btn_delete' => false,
'btn_catalogue' => 'admin',
'label' => 'name_of_your_label',
], [
'placeholder' => 'choose media',
'edit' => 'inline',
'inline' => 'table',
'sortable' => 'id',
])
Many-To-Many : sonata_type_model
You can make many-to-many with doctrine:
class Gallery
{
// ...
/**
* Unidirectional Many-To-Many ()
*
* Every Gallery can have a lot of medias
*
* #ORM\ManyToMany(targetEntity="\Entity\Media")
* #ORM\JoinTable(
* name="gallery_media_table",
* joinColumns={#ORM\JoinColumn(name="gallery_id", referencedColumnName="id", onDelete="CASCADE")},
* inverseJoinColumns={#ORM\JoinColumn(name="media_id", referencedColumnName="id", onDelete="CASCADE")}
* )
*
* #Assert\Valid()
*/
protected $medias;
Then in your GalleryAdmin you should use sonata_type_model:
$formMapper
->add('medias', 'sonata_type_model', [
'multiple' => true,
'expanded' => true, // or false
'class' => Media::class,
'property' => 'name', // or any field in your media entity
'label' => 'your_label',
'btn_add' => true,
'btn_list' => false,
'btn_delete' => true,
'btn_catalogue' => 'admin', // or your own translate catalogue in my case file admin.en.yml
])