SluggableBehavior initial implementation

framework/behaviors/SluggableBehavior.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\behaviors;
+
+use yii\base\InvalidConfigException;
+use yii\db\BaseActiveRecord;
+use yii\helpers\Inflector;
+
+/**
+ * SluggableBehavior
+ *
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @since 2.0
+ */
+class SluggableBehavior extends AttributeBehavior
+{
+    /**
+     * @inheritdoc
+     */
+    public $attributes = [
+        BaseActiveRecord::EVENT_BEFORE_VALIDATE => 'slug',
+    ];
+    /**
+     * @var string
+     */
+    public $attribute;
+
+    /**
+     * @inheritdoc
+     */
+    public function init()
+    {
+        if ($this->attribute === null && $this->value === null) {
+            throw new InvalidConfigException('Either "attribute" or "value" properties must be specified.');
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function getValue($event)
+    {
+        if ($this->attribute !== null) {
+            $this->value = Inflector::slug($this->owner->{$this->attribute});
+        }
+
+        return parent::getValue($event);
+    }
+}