Logging Actions with Laravel Morph Maps

[crynobone]

Laravel Nova will store all actions completed and will utilise Relation::morphMap() if defined. It's also true with Relation::enforceMorphMap() however you have to be aware that you would need to define all Models and Pivot Models used to define Resource.

As an example, imagine you have Role and User with belongs-to-many relationship and Post, Tag with morph-to-many relationship:

<?php 

namespace App\Models;

use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\Pivot;
use Illuminate\Database\Eloquent\Relations\MorphPivot;

class User extends Authenticatable
{
    public function roles()
    {
        return $this->belongsToMany(Role::class)->using(UserRole::class);
    }
}

class Role extends Model
{
    public function users()
    {
        return $this->belongsToMany(User::class)->using(UserRole::class);
    }
}

class UserRole extends Pivot 
{
    //
}

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

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

class Taggable extends MorphPivot
{
    //
}

Relation::enforceMorphMap([
    'roles' => Role::class,
    'users' => User::class,
    'user_role' => UserRole::class,

    'posts' => Post::class,
    'tags' => Tag::class,
    'taggable' => Taggable::class,
]);

As shown above, you need to also define the Pivot Model used to allow Laravel Nova to properly log attaching and detaching roles events in the application when you used Relation::enforceMorphMap().

[wivaku]

Is this a workaround or by design?

How is that used for polymorphic many to many (e.g. Tags from Laravel and Laravel Nova example)?

For each of the models using Tags I currently have:

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

Laravel documentation states that:

custom polymorphic many-to-many pivot models should extend the Illuminate\Database\Eloquent\Relations\MorphPivot class

Don't think the Tags example is a custom pivot model, but regardless: what would a complete pivot class example using ->using(...) be for that case for both the tags() function and the Relation::enforceMorphMap?

[crynobone]

Is this a workaround or by design?

It is by design if you want to enforce yourselves with strict using enforceMorphMap(), otherwise morphMap() would do fine. Most Laravel app doesn't interact directly on the belongs-to-many or morph-to-many on polymorphic relationship but when you do, you need to do this too.

Don't think the Tags example is a custom pivot model, but regardless: what would a complete pivot class example using ->using(...) be for that case for both the tags() function and the Relation::enforceMorphMap?

Example updated using Illuminate\Database\Eloquent\Relations\MorphPivot

MorphToMany relationship extends BelongsToMany, so it'll be the same: https://github.com/laravel/framework/blob/8.x/src/Illuminate/Database/Eloquent/Relations/MorphToMany.php