backend helper

BackendHelper.php

<?php

// Backend MediaGroups Helper
$this->media = $this->get('media_library.helper.backend')->create(
    $this->frm,
    $this->tpl,
    $this->header,
    array(
        // create new with specified MediaGroup type
        $this->get('media_library.factory.backend.group')->create(
            $this->mediaGroupType
        )
    )
);


class BackendHelper
{
    /** @var boolean */
    protected $isSaved = false;

    /** @var BackendMediaGroups */
    protected $backendMediaGroups;

    /** @var BackendMediaGroupHelper */
    protected $backendMediaGroupHelper;


    public function create(
        $backendMediaGroups
    ) {
        // Define backendMediaGroups
        $this->backendMediaGroups = $this->backendMediaGroupsFactory->create(
            $backendMediaGroups
        );
    }

    public function loadForm()
    {

    }

    public function parse()
    {

    }

    public function save()
    {
        if ($this->isSaved) {
            throw new \Exception('You can\'t use ->save() twice on the media helper.');
        }

        // We must redefine isSaved
        $this->isSaved = true;

        foreach ($this->backendMediaGroups as $key => $backendMediaGroup) {
            $this->backendMediaGroupHelper->save(
                $backendMediaGroup,
                $this->form->getField('media_ids_' . $key)->getValue()
            );
        }
    }
}

class BackendMediaGroupHelper
{
    /** @var MediaGroupManager */
    protected $mediaGroupManager;

    /** @var MediaGroupMediaItemFactory */
    protected $mediaGroupMediaItemFactory;

    /** @var MediaGroupMediaItemManager */
    protected $mediaGroupMediaItemManager;

    /** @var MediaItemRepository */
    protected $mediaItemRepository;

    /**
     * Construct
     *
     * @param MediaGroupManager $mediaGroupManager
     * @param MediaGroupMediaItemManager $mediaGroupMediaItemManager
     * @param MediaGroupMediaItemFactory $mediaGroupMediaItemFactory
     * @param MediaItemRepository $mediaItemRepository
     */
    public function __construct(
        MediaGroupManager $mediaGroupManager,
        MediaGroupMediaItemManager $mediaGroupMediaItemManager,
        MediaGroupMediaItemFactory $mediaGroupMediaItemFactory,
        MediaItemRepository $mediaItemRepository
    ) {
        $this->mediaGroupManager = $mediaGroupManager;
        $this->mediaGroupMediaItemManager = $mediaGroupMediaItemManager;
        $this->mediaGroupMediaItemFactory = $mediaGroupMediaItemFactory;
        $this->mediaItemRepository = $mediaItemRepository;
    }

    /**
     * Save
     *
     * @param BackendMediaGroup $backendMediaGroup
     * @param string formValue
     */
    public function save(
        BackendMediaGroup $backendMediaGroup,
        $formValueNewMediaIds
    ) {
        
    }
}