Laravel validation site belongs to user - laravel

Question

My User.php
class User extends Authenticatable
{
public function sites()
{
return $this->hasMany(Site::class);
}
}
My Site.php
class Site extends Model
{
public function user()
{
return $this->belongsTo(User::class);
}
}
My routes.php
Route::resource('site', 'SiteController');
My SiteController.php
class SiteController extends Controller
{
public function edit(int $id)
{
$site = Auth::user()->sites()->find($id);
return view('site.edit', compact('site'));
}
}
How can I validate that the site belongs to user? I understand that in my case if site doesn't belong to user, $site variable will be null. But I want more declarative way, something like laravel requests, because I need the same check in show, update, and destroy methods. But I cannot use laravel request, because checking is something like this
$siteId = Route::current()->param('site');
$ids = Auth::user()->sites()->pluck('id')->toArray();
$result = in_array($siteId, $ids);
Can anyone suggest how to achieve my goal?

Answer 1

Since I use laravel 5.2, solution with route filters is deprecated. Instead route filter we should use middleware.
app/Http/Middleware/RestrictPermission.php
class RestrictPermission
{
public function handle($request, Closure $next)
{
$siteId = Route::current()->parameter('site');
if (!Auth::user()->sites()->find($siteId)) {
abort(403);
}
return $next($request);
}
}
app/Http/Kernel.php
class Kernel extends HttpKernel
{
protected $routeMiddleware = [
'restrict.permission' => RestrictPermission::class,
];
}
SiteController.php
class SiteController extends Controller
{
public function __construct()
{
$this->middleware('restrict.permission', ['except' => [
'index', 'create', 'store',
]]);
}
public function edit(int $id)
{
$site = Auth::user()->sites()->find($id);
return view('site.edit', compact('site'));
}
}