• Laravel Version: 5.4
• PHP Version: 7
• Database Driver & Version: Mysql

Description:

The problem with morphMap is that you cannot extend a model and use the same map key.

Steps To Reproduce:

Let's say you have a User model with a polymorphic m-t-m relationship with Tags.

User Model looks like

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

The morphMap looks like

'users' => 'App\Models\User' 

Now let's say you have a SpecialUser model that extends User. They both use the same table
and you want to use the same tags relationship.

This will not work

$specialUser = SpecialUser::find(1); $specialUser->tags(); 

Potential Solution:

Restore the deprecated protected $morphClass model member

 public function getMorphClass() { if ($this->morphClass !== null) { return $this->morphClass; } $morphMap = Relation::morphMap(); $class = static::class; if (! empty($morphMap) && in_array($class, $morphMap)) { return array_search($class, $morphMap, true); } return $class; }