I have a Subscriber model
// Subscriber Model
id
user_id
subscribable_id
subscribable_type
public function user()
{
return $this->belongsTo('App\User');
}
public function subscribable()
{
return $this->morphTo();
}
And a Topic model
// Topic Model
public function subscribers()
{
return $this->morphMany('App\Subscriber', 'subscribable');
}
And I want to get all users through Subscriber model, to notify them like
Notification::send($topic->users, new Notification($topic));
// Topic Model
public function users()
{
return $this->hasManyThrough('App\User', 'App\Subscriber');
}
Any ideas?
// Topic Model
public function users()
{
return $this->hasManyThrough('App\User', 'App\Subscriber', '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.
In addition to Matt's approach, the following code also could be another solution:
//Topic Model
public function users()
{
return $this->belongsToMany(User::class, 'subscribers', 'subscribale_id', 'user_id')
->where('subscribale_type', static::class);
}
In this way Subscriber treated as a pivot table and second argument is table name for pivot.
The third argument is the foreign key name of the model on which you are defining the relationship, while the fourth argument is the foreign key name of the model that you are joining to. Read more here.
Consider the where clause after belongsToMany to filter only the current model.
What you're after is not hasManyThrough, but morphedByMany.
hasManyThrough is useful when you have A one-to-many B, B one-to-many C, and you want to use A to fetch many C.
What you have is a polymorphic pivot table sitting in the middle between A and C.
// Topic Model
public function users()
{
return $this->morphedByMany('App\User', 'subscribable', 'pivot/subscriber_table_name');
}
Docs: https://laravel.com/docs/6.x/eloquent-relationships#many-to-many-polymorphic-relations