MorphToMany Accessing Blank Models?

[jjjrmy]

• Laravel Version: 8
• Nova Version: 3.31
• PHP Version: 8
• Database Driver & Version: MySQL

Description:

If you add a Ray debug to the relationship method, the API request is returning blank models as shown below when accessing a Post resource.

class Post extends Model {
  public function tags() {
     ray(request()->url(), $this)->label(__FUNCTION__);
     return $this->morphToMany(Tag::class, 'taggable');
  }
}

In my example this Post has 3 Tags, and it seem to be outputting 3 blank Post models in the debug output.
This is causing me problems and doesn't seem right.

Why is this happening and is there a way to prevent it?

Detailed steps to reproduce the issue on a fresh Nova installation:

1.) Follow this structure for creating Laravel & Nova Models:
https://laravel.com/docs/8.x/eloquent-relationships#many-to-many-polymorphic-relations
2.) Create / Seed the Tags and Posts + Videos
3.) Navigate to a Post

[jjjrmy]

@crynobone can you please tell me what info is needed?

[crynobone]

All bug report should come with full reproducing code, not just code snippets.

[jjjrmy]

You can just copy the code from the Laravel documentation, but here it is...
Migration

class CreateMorphsTable extends Migration
{
    public function up()
    {
        Schema::create('posts', function (Blueprint $table) {
            $table->id();
            $table->text('name');
            $table->timestamps();
        });
        Schema::create('videos', function (Blueprint $table) {
            $table->id();
            $table->text('name');
            $table->timestamps();
        });
        Schema::create('tags', function (Blueprint $table) {
            $table->id();
            $table->text('name');
            $table->timestamps();
        });
        Schema::create('taggables', function (Blueprint $table) {
            $table->id();
            $table->foreignId('tag_id');
            $table->morphs('taggable');
            $table->timestamps();
        });
    }
}

Models

class Video extends Model
{
    public function tags()
    {
        return $this->morphToMany(Tag::class, 'taggable');
    }
}

class Post extends Model
{
    public function tags()
    {
        ray(request()->url(), $this)->label(__FUNCTION__);
        return $this->morphToMany(Tag::class, 'taggable');
    }
}

class Tag extends Model
{
    public function posts()
    {
        return $this->morphedByMany(Post::class, 'taggable');
    }

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

Nova Models

class Video extends Resource
{
    public function fields(Request $request)
    {
        return [
            ID::make(__('ID'), 'id')->sortable(),
            Text::make('Name'),
            MorphToMany::make('Tags'),
        ];
    }
}

class Post extends Resource
{
    public function fields(Request $request)
    {
        return [
            ID::make(__('ID'), 'id')->sortable(),
            Text::make('Name'),
            MorphToMany::make('Tags'),
        ];
    }
}

class Tag extends Resource
{
    public function fields(Request $request)
    {
        return [
            ID::make(__('ID'), 'id')->sortable(),
            Text::make('Name'),
        ];
    }
}

[jjjrmy]

I know it's doing something it shouldn't because if you access Post::first()->tags it will Ray dump just 1 instance of the Post model and no other blank models, but what ever is happening in the API Resource is calling those extra blank models.

[crynobone]

Calling blank model occurred in some API request and that is to be expected depending on what information needed for that particular API request.

I don't think there any bug here, as that is expected behaviour.

[jjjrmy]

@crynobone
Can you please explain more because this doesn't seem to be expected behavior...

If you do Post::find(1)->tags in Tinkerwell, Ray will only dump one output of the Post model.
If you access /nova/resources/posts/1 it calls the API /nova-api/tags?...&viaResource=posts&viaResourceId=1&viaRelationship=tags&relationshipType=morphToMany, Ray will dump as shown in the image above.
(In both cases 3 tags are attached to the Post.)

They are both accessing the same data, what ever is happening in that API endpoint I wouldn't call "to be expected" as that doesn't occur when doing it outside of Nova.

What is happening in the endpoint that is causing this?

[crynobone]

above are only your expectations, what we do is only Tag::query(), new Tag() or Tag::find()