Fixes issue #235: Implemented AutoTimestamp.

yii/behaviors/AutoTimestamp.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\Behavior;
+use yii\db\Expression;
+use yii\db\ActiveRecord;
+
+/**
+ * AutoTimestamp will automatically fill the attributes about creation time and updating time.
+ *
+ * AutoTimestamp fills the attributes when the associated AR model is being inserted or updated.
+ * You may specify an AR to use this behavior like the following:
+ *
+ * ~~~
+ * public function behaviors()
+ * {
+ *     return array(
+ *         'timestamp' => array(
+ *             'class' => 'yii\behaviors\AutoTimestamp',
+ *         ),
+ *     );
+ * }
+ * ~~~
+ *
+ * By default, the attribute for keeping the creation time is named as "create_time", and the attribute
+ * for updating time is "update_time". You may customize the names via [[createAttribute]] and [[updateAttribute]].
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class AutoTimestamp extends Behavior
+{
+	/**
+	 * @var string The name of the attribute to store the creation time.  Set to null to not
+	 * use a timestamp for the creation attribute.  Defaults to 'create_time'
+	 */
+	public $createAttribute = 'create_time';
+	/**
+	 * @var string The name of the attribute to store the modification time.  Set to null to not
+	 * use a timestamp for the update attribute.  Defaults to 'update_time'
+	 */
+	public $updateAttribute = 'update_time';
+	/**
+	 * @var string|Expression The expression that will be used for generating the timestamp.
+	 * This can be either a string representing a PHP expression (e.g. 'time()'),
+	 * or an [[Expression]] object representing a DB expression (e.g. `new Expression('NOW()')`).
+	 * If not set, it will use the value of `time()` to fill the attributes.
+	 */
+	public $timestamp;
+
+
+	/**
+	 * Declares event handlers for the [[owner]]'s events.
+	 * @return array events (array keys) and the corresponding event handler methods (array values).
+	 */
+	public function events()
+	{
+		return array(
+			ActiveRecord::EVENT_BEFORE_INSERT => 'beforeInsert',
+			ActiveRecord::EVENT_BEFORE_UPDATE => 'beforeInsert',
+		);
+	}
+
+	/**
+	 * This is the event handler for the "beforeInsert" event of the associated AR object.
+	 */
+	public function beforeInsert()
+	{
+		if ($this->createAttribute !== null) {
+			$this->owner->{$this->createAttribute} = $this->evaluateTimestamp($this->createAttribute);
+		}
+	}
+
+	/**
+	 * This is the event handler for the "beforeUpdate" event of the associated AR object.
+	 */
+	public function beforeUpdate()
+	{
+		if ($this->updateAttribute !== null) {
+			$this->owner->{$this->updateAttribute} = $this->evaluateTimestamp($this->updateAttribute);
+		}
+	}
+
+	/**
+	 * Gets the appropriate timestamp depending on the column type $attribute is
+	 * @param string $attribute attribute name
+	 * @return mixed the timestamp value
+	 */
+	protected function evaluateTimestamp($attribute)
+	{
+		if ($this->timestamp instanceof Expression) {
+			return $this->timestamp;
+		} elseif ($this->timestamp !== null) {
+			return eval('return ' . $this->timestamp . ';');
+		} else {
+			return time();
+		}
+	}
+}