Laravel - Eloquent - Dynamically defined relationship

Question

Is it possible to set a model\'s relationship dynamically? For example, I have model Page, and I want to add relationship banners() to it without a

Answer 1

Just in case anyone is looking for a Laravel 8 answer:

Let's say I define my relationships in a single method of my model:

public function relationships()
{
    return [
        'user' => $this->belongsTo(User::class, 'user_id'),
    ];
}

Now, in my app service provider, I can use the resolveRelationUsing method. I've done this by iterating through the models folder and checking all models which contain the aforementioned method:

    foreach ((new Filesystem)->allFiles(app_path('Models')) as $file) {
        $namespace = 'App\\Models\\' . str_replace(['/', '.php'], ['\\', ''], $file->getRelativePathname());
        $class = app($namespace);

        if (method_exists($class, 'relationships')) {
            foreach ($class->relationships() as $key => $relationship) {
                $class->resolveRelationUsing($key, function () use ($class, $key) {
                    return $class->relationships()[$key];
                });
            }
        }
    }