Laravel - treating belongsTo() that returns null

• Laravel 5.5

I have a model (request) that returns customer id, it's receiving it from a different machine so I want to treat non-existent values (i.e. id that doesn't exist returning the eloquent as null).

so for:

public function customer()
{
    return $this->belongsTo('App\Customer', 'site_user');
}

• I've tried the following:

  public function getSiteUserAttribute() { if (!$this->relationLoaded('customer')) $this->load('customer');

      return $this->getRelation('customer') ?: $this->nullCustomer();
  }
  
  

and nullCustomer() :

private function nullCustomer()
{
    $nonExist = 'non-exist-customer';

    $siteUser = new \Illuminate\Support\Collection;
    $siteUser->first_name = $nonExist;
    $siteUser->last_name = $nonExist;
    $siteUser->email = $nonExist;

    return $siteUser;
}

Yet Laravel is returning an error I can't really make sense of:

Undefined property: App\Request::$site_user (View: C:\xampp700\htdocs\stackOverflow\resources\views\request\index.blade.php)

it's obviously related to getSiteUserAttribute() which extrapolates site_user, but I can't understand what's the issue.

I can isset() for every place that this relation is called, but i'm working with a smart framework, so I doubt that would be the best practice.

Just to reiterate, i'm trying ot treat null belongsTo() that wouldn't break the view.

via Chebli Mohamed