php - Laravel Polymorphic Relations Has Many Through

Question

I have a Subscriber model

// Subscriber Model

id
user_id
subscribable_id
subscribable_type

public function user()
{
    return $this->belongsTo('AppUser');
}

public function subscribable()
{
    return $this->morphTo();
}

And a Topic model

// Topic Model

public function subscribers()
{
    return $this->morphMany('AppSubscriber', 'subscribable');
}

And I want to get all users through Subscriber model, to notify them like

Notification::send($topic->users, new Notification($topic));

// Topic Model


public function users()
{
    return $this->hasManyThrough('AppUser', 'AppSubscriber');
}

Any ideas?

Answer 1

// Topic Model

public function users()
{
    return $this->hasManyThrough('AppUser', 'AppSubscriber', 'subscribable_id')
        ->where(
            'subscribable_type', 
            array_search(static::class, Relation::morphMap()) ?: static::class
        );
}

Polymorphic hasManyThrough relationships are the same as any others, but with an added constraint on the subscribable_type, which can be retrieved from the Relation::morphMap() array, or by using the class name directly.