better handling with exceptions in __toString()

framework/yii/web/Response.php

@@ -781,7 +781,7 @@ class Response extends \yii\base\Response
 		if (is_array($this->content)) {
 			$this->content = 'array()';
 		} elseif (is_object($this->content)) {
-			$this->content = method_exists($this->content, '__toString') ? (string)$this->content : get_class($this->content);
+			$this->content = method_exists($this->content, '__toString') ? $this->content->__toString() : get_class($this->content);
 		}
 	}
 }

framework/yii/widgets/ActiveField.php

@@ -128,7 +128,14 @@ class ActiveField extends Component
 	 */
 	public function __toString()
 	{
-		return $this->render();
+		// __toString cannot throw exception
+		// use trigger_error to bypass this limitation
+		try {
+			return $this->render();
+		} catch (\Exception $e) {
+			trigger_error($e->getMessage());
+			return '';
+		}
 	}
 
 	/**