improved session error handling

fixes #1946

extensions/mongodb/Session.php

@@ -8,6 +8,7 @@
 namespace yii\mongodb;
 
 use Yii;
+use yii\base\ErrorHandler;
 use yii\base\InvalidConfigException;
 use yii\di\Instance;
 
@@ -49,6 +50,7 @@ class Session extends \yii\web\Session
      */
     public $sessionCollection = 'session';
 
+
     /**
      * Initializes the Session component.
      * This method will initialize the [[db]] property to make sure it refers to a valid MongoDB connection.
@@ -148,10 +150,11 @@ class Session extends \yii\web\Session
                 ['upsert' => true]
             );
         } catch (\Exception $e) {
-            if (YII_DEBUG) {
-                echo $e->getMessage();
-            }
-            // it is too late to log an error message here
+            $exception = ErrorHandler::convertExceptionToString($e);
+            // its too late to use Yii logging here
+            error_log($exception);
+            echo $exception;
+
             return false;
         }
 

framework/base/ErrorHandler.php

@@ -246,4 +246,42 @@ class ErrorHandler extends Component
             }
         }
     }
+
+    /**
+     * Converts an exception into a PHP error.
+     *
+     * This method can be used to convert exceptions inside of methods like `__toString()`
+     * to PHP errors because exceptions cannot be thrown inside of them.
+     * @param \Exception $exception the exception to convert to a PHP error.
+     */
+    public static function convertExceptionToError($exception)
+    {
+        trigger_error(static::convertExceptionToString($exception), E_USER_ERROR);
+    }
+
+    /**
+     * Converts an exception into a simple string.
+     * @param \Exception $exception the exception being converted
+     * @return string the string representation of the exception.
+     */
+    public static function convertExceptionToString($exception)
+    {
+        if ($exception instanceof Exception && ($exception instanceof UserException || !YII_DEBUG)) {
+            $message = "{$exception->getName()}: {$exception->getMessage()}";
+        } elseif (YII_DEBUG) {
+            if ($exception instanceof Exception) {
+                $message = "Exception ({$exception->getName()})";
+            } elseif ($exception instanceof ErrorException) {
+                $message = "{$exception->getName()}";
+            } else {
+                $message = 'Exception';
+            }
+            $message .= " '" . get_class($exception) . "' with message '{$exception->getMessage()}' \n\nin "
+                . $exception->getFile() . ':' . $exception->getLine() . "\n\n"
+                . "Stack trace:\n" . $exception->getTraceAsString();
+        } else {
+            $message = 'Error: ' . $exception->getMessage();
+        }
+        return $message;
+    }
 }

framework/mail/BaseMessage.php

@@ -7,6 +7,7 @@
 
 namespace yii\mail;
 
+use yii\base\ErrorHandler;
 use yii\base\Object;
 use Yii;
 
@@ -58,7 +59,7 @@ abstract class BaseMessage extends Object implements MessageInterface
         try {
             return $this->toString();
         } catch (\Exception $e) {
-            trigger_error($e->getMessage() . "\n\n" . $e->getTraceAsString());
+            ErrorHandler::convertExceptionToError($e);
             return '';
         }
     }

framework/web/DbSession.php

@@ -182,10 +182,11 @@ class DbSession extends Session
                     ->execute();
             }
         } catch (\Exception $e) {
-            if (YII_DEBUG) {
-                echo $e->getMessage();
-            }
-            // it is too late to log an error message here
+            $exception = ErrorHandler::convertExceptionToString($e);
+            // its too late to use Yii logging here
+            error_log($exception);
+            echo $exception;
+
             return false;
         }
 

framework/web/ErrorHandler.php

@@ -131,32 +131,6 @@ class ErrorHandler extends \yii\base\ErrorHandler
         return $array;
     }
 
-    /**
-     * Converts an exception into a simple string.
-     * @param \Exception $exception the exception being converted
-     * @return string the string representation of the exception.
-     */
-    protected function convertExceptionToString($exception)
-    {
-        if ($exception instanceof Exception && ($exception instanceof UserException || !YII_DEBUG)) {
-            $message = "{$exception->getName()}: {$exception->getMessage()}";
-        } elseif (YII_DEBUG) {
-            if ($exception instanceof Exception) {
-                $message = "Exception ({$exception->getName()})";
-            } elseif ($exception instanceof ErrorException) {
-                $message = "{$exception->getName()}";
-            } else {
-                $message = 'Exception';
-            }
-            $message .= " '" . get_class($exception) . "' with message '{$exception->getMessage()}' \n\nin "
-                . $exception->getFile() . ':' . $exception->getLine() . "\n\n"
-                . "Stack trace:\n" . $exception->getTraceAsString();
-        } else {
-            $message = 'Error: ' . $exception->getMessage();
-        }
-        return $message;
-    }
-
     /**
      * Converts special characters to HTML entities.
      * @param string $text to encode.

framework/widgets/ActiveField.php

@@ -8,6 +8,7 @@ namespace yii\widgets;
 
 use Yii;
 use yii\base\Component;
+use yii\base\ErrorHandler;
 use yii\helpers\ArrayHelper;
 use yii\helpers\Html;
 use yii\base\Model;
@@ -140,8 +141,7 @@ class ActiveField extends Component
         try {
             return $this->render();
         } catch (\Exception $e) {
-            trigger_error($e->getMessage() . "\n\n" . $e->getTraceAsString());
-
+            ErrorHandler::convertExceptionToError($e);
             return '';
         }
     }