diff --git a/framework/yii/base/ActionEvent.php b/framework/yii/base/ActionEvent.php
index adfeddc..293d5bd 100644
--- a/framework/yii/base/ActionEvent.php
+++ b/framework/yii/base/ActionEvent.php
@@ -11,10 +11,7 @@ namespace yii\base;
  * ActionEvent represents the event parameter used for an action event.
  *
  * By setting the [[isValid]] property, one may control whether to continue running the action.
- * @property boolean $isValid Event handlers of
- * [[Controller::EVENT_BEFORE_ACTION]] may set this property to decide whether
- * to continue running the current action.
- * 
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
@@ -28,6 +25,12 @@ class ActionEvent extends Event
 	 * @var mixed the action result. Event handlers may modify this property to change the action result.
 	 */
 	public $result;
+	/**
+	 * @var boolean whether to continue running the action. Event handlers of
+	 * [[Controller::EVENT_BEFORE_ACTION]] may set this property to decide whether
+	 * to continue running the current action.
+	 */
+	public $isValid = true;
 
 	/**
 	 * Constructor.
@@ -39,4 +42,4 @@ class ActionEvent extends Event
 		$this->action = $action;
 		parent::__construct($config);
 	}
-}
+}
\ No newline at end of file
diff --git a/framework/yii/base/Event.php b/framework/yii/base/Event.php
index 4c8ffcb..ebd7193 100644
--- a/framework/yii/base/Event.php
+++ b/framework/yii/base/Event.php
@@ -46,11 +46,6 @@ class Event extends Object
 	 */
 	public $data;
 
-	/**
-	 * @var boolean whether to continue execution of process or not.
-	 */
-	public $isValid = true;
-
 	private static $_events = [];
 
 	/**
@@ -185,4 +180,4 @@ class Event extends Object
 			}
 		} while (($class = get_parent_class($class)) !== false);
 	}
-}
+}
\ No newline at end of file
diff --git a/framework/yii/base/MailEvent.php b/framework/yii/base/MailEvent.php
index 188c7d3..3e0ae76 100644
--- a/framework/yii/base/MailEvent.php
+++ b/framework/yii/base/MailEvent.php
@@ -24,7 +24,13 @@ class MailEvent extends Event
 	 */
 	public $message;
 	/**
-	 * 
+	 * @var boolean if message send was successful
 	 */
 	public $isSuccessful;
+	/**
+	 * @var boolean whether to continue send. Event handlers of
+	 * [[\yii\mail\BaseMailer::EVENT_BEFORE_SEND]] may set this property to decide whether
+	 * to continue send or not.
+	 */
+	public $isValid = true;
 }
diff --git a/framework/yii/base/ModelEvent.php b/framework/yii/base/ModelEvent.php
index b4b602d..f10f83a 100644
--- a/framework/yii/base/ModelEvent.php
+++ b/framework/yii/base/ModelEvent.php
@@ -11,11 +11,15 @@ namespace yii\base;
  * ModelEvent class.
  *
  * ModelEvent represents the parameter needed by model events.
- * @property boolean $isValid A model is in valid status if it passes validations or certain checks.
- * 
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
 class ModelEvent extends Event
 {
-}
+	/**
+	 * @var boolean whether the model is in valid status. Defaults to true.
+	 * A model is in valid status if it passes validations or certain checks.
+	 */
+	public $isValid = true;
+}
\ No newline at end of file
diff --git a/framework/yii/base/ViewEvent.php b/framework/yii/base/ViewEvent.php
index 70ba96d..ec4d461 100644
--- a/framework/yii/base/ViewEvent.php
+++ b/framework/yii/base/ViewEvent.php
@@ -10,11 +10,6 @@ namespace yii\base;
 /**
  * ViewEvent represents events triggered by the [[View]] component.
  *
- * @property boolean $isValid whether to continue rendering the view file. Event handlers of
- *[[View::EVENT_BEFORE_RENDER]] may set this property to decide whether
- * to continue rendering the current view file.
- * 
- * 
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
@@ -31,6 +26,12 @@ class ViewEvent extends Event
 	 * @var string the view file path that is being rendered by [[View::renderFile()]].
 	 */
 	public $viewFile;
+	/**
+	 * @var boolean whether to continue rendering the view file. Event handlers of
+	 * [[View::EVENT_BEFORE_RENDER]] may set this property to decide whether
+	 * to continue rendering the current view file.
+	 */
+	public $isValid = true;
 
 	/**
 	 * Constructor.
@@ -42,4 +43,4 @@ class ViewEvent extends Event
 		$this->viewFile = $viewFile;
 		parent::__construct($config);
 	}
-}
+}
\ No newline at end of file