added RBAC

lib/User/Validator/RbacRuleValidator.php

@@ -0,0 +1,26 @@
+<?php
+namespace Da\User\Validator;
+
+use ReflectionClass;
+use Exception;
+use yii\validators\Validator;
+use Yii;
+
+class RbacRuleValidator extends Validator
+{
+    protected function validateValue($value)
+    {
+        try {
+            $class = new ReflectionClass($value);
+        } catch (Exception $e) {
+            return [Yii::t('user', 'Class "{0}" does not exist', $value), []];
+        }
+
+        if ($class->isInstantiable() == false) {
+            return [Yii::t('user', 'Rule class can not be instantiated'), []];
+        }
+        if ($class->isSubclassOf('\yii\rbac\Rule') == false) {
+            return [Yii::t('user', 'Rule class must extend "yii\rbac\Rule"'), []];
+        }
+    }
+}