Added a new authorizer method for checking a user has a permission (for use in sprinkle level access checks)

(cherry picked from commit 97ded0eb08)

src/ServicesProvider/ServicesProvider.php

@@ -9,6 +9,7 @@
 
 namespace UserFrosting\Sprinkle\UFTweaks\ServicesProvider;
 
+use Illuminate\Database\Capsule\Manager as Capsule;
 use Monolog\Formatter\LineFormatter;
 use Monolog\Handler\StreamHandler;
 use Monolog\Logger;
@@ -150,6 +151,25 @@ class ServicesProvider
                 }
             );
 
+            /*
+             * Check if the specified user (by user_id) has a particular permission.
+             *
+             * @param  int  $user_id the id of the user.
+             * @param  int  $permission_slug slug of the permission to check.
+             * @return bool true if the user has the permission, false otherwise.
+             */
+            $authorizer->addCallback(
+                'has_permission',
+                function ($user_id, $permission_slug) {
+                    return Capsule::table('role_users')
+                        ->join('permission_roles', 'role_users.role_id', '=', 'permission_roles.role_id')
+                        ->join('permissions', 'permission_roles.permission_id', '=', 'permissions.id')
+                        ->where('user_id', $user_id)
+                        ->where('slug', $permission_slug)
+                        ->count() > 0;
+                }
+            );
+
             return $authorizer;
         });