Backpack 4.1 morphToMany relation

App\Http\Controllers\PostCrudController

<?php

namespace App\Http\Controllers;

use Backpack\CRUD\app\Http\Controllers\CrudController;
use Backpack\CRUD\app\Library\CrudPanel\CrudPanelFacade as CRUD;

class PostCrudController extends CrudController
{
    use \Backpack\CRUD\app\Http\Controllers\Operations\CreateOperation { store as traitStore; } //IMPORTANT HERE
    use \Backpack\CRUD\app\Http\Controllers\Operations\UpdateOperation { update as traitUpdate; } //IMPORTANT HERE

    public function setup()
    {
        CRUD::setModel(\App\Models\Article::class);
        CRUD::setRoute(config('backpack.base.route_prefix') . '/article');
        CRUD::setEntityNameStrings('article', 'articles');
    }
    
    protected function setupCreateOperation()
    {
        CRUD::field('title');
        
        CRUD::field('tags_list')
              ->type('repeatable')
              ->fields([
                [
                    'name' => 'tag_id',
                    'type' => 'select2',
                    'model' => 'App\Models\Tag,
                    'attribute' => 'name'
                ],
                [
                    'name' => 'note',
                    'type' => 'text'
                ]])
        ]);      
    }

    protected function setupUpdateOperation()
    {
        $this->setupCreateOperation();
    }

    public function store()
    {
        $tags = collect(json_decode(request('tags_list'), true));

        $response = $this->traitStore();

        $this->crud->entry->tags()->sync($tags);

        return $response;
    };

    public function update()
    {
        $tags = collect(json_decode(request('tags_list'), true));

        $response = $this->traitUpdate();
        
        $this->crud->entry->tags()->sync($tags);

        return $response;
    }

App\Models\Post

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Post extends Model
{
    use \Backpack\CRUD\app\Models\Traits\CrudTrait;
    
    protected $casts = [
        'id' => 'integer',
    ];

    public function tags()
    {
        return $this->morphToMany(\App\Models\Tag::class, 'taggable')->withPivot('note');
    }
    
    //acessor to get the video populated in the repeatable field again
    public function getTagsListAttribute() {
        return json_encode($this->tags->map(function($tag) {
            return ['tag_id' => $tag->id, 'note' => $tag->pivot->note];
        }));
    }
}

App\Models\Tag

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Tag extends Model
{
    use \Backpack\CRUD\app\Models\Traits\CrudTrait;

    public function posts()
    {
        return $this->morphedByMany(\App\Models\Post::class, 'taggable');
    }
    
    public function videos()
    {
        return $this->morphedByMany(\App\Models\Video::class, 'taggable');
    }
}

App\Models\Video

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Video extends Model
{
    use \Backpack\CRUD\app\Models\Traits\CrudTrait;
    
    protected $casts = [
        'id' => 'integer',
    ];

    public function tags()
    {
        return $this->morphToMany(\App\Models\Tag::class, 'taggable')->withPivot('note');
    }
    
    //acessor to get the video populated in the repeatable field again
    public function getTagsListAttribute() {
        return json_encode($this->tags->map(function($tag) {
            return ['tag_id' => $tag->id, 'note' => $tag->pivot->note];
        }));
    }
}