diff --git a/framework/YiiBase.php b/framework/YiiBase.php
index bc5b2cc..b3981d5 100644
--- a/framework/YiiBase.php
+++ b/framework/YiiBase.php
@@ -160,6 +160,9 @@ class YiiBase
 	 * In the latter case, the root alias will be replaced by the corresponding registered path
 	 * and the remaining part will be appended to it.
 	 *
+	 * In case the given alias is not an alias (i.e., not starting with '@'),
+	 * it will be returned back as is.
+	 *
 	 * Note, this method does not ensure the existence of the resulting path.
 	 * @param string $alias alias
 	 * @return mixed path corresponding to the alias, false if the root alias is not previously registered.
@@ -175,6 +178,9 @@ class YiiBase
 			if (isset(self::$aliases[$rootAlias])) {
 				return self::$aliases[$alias] = self::$aliases[$rootAlias] . substr($alias, $pos);
 			}
+			else if($alias[0] !== '@') { // not an alias
+				return $alias;
+			}
 		}
 		return false;
 	}
@@ -344,7 +350,6 @@ class YiiBase
 		}
 
 		if ($object instanceof Initable) {
-			$object->preinit();
 			foreach ($config as $name => $value) {
 				$object->$name = $value;
 			}
diff --git a/framework/base/Component.php b/framework/base/Component.php
index 8619a39..8589e7d 100644
--- a/framework/base/Component.php
+++ b/framework/base/Component.php
@@ -307,9 +307,9 @@ class Component
 	 * Creates a new component instance.
 	 *
 	 * This method differs from the PHP `new` operator in that it does the following
-	 * additional work after the component is created:
+	 * steps to create a new component instance:
 	 *
-	 * - Call [[Initable::preinit|preinit]] if the class implements [[Initable]];
+	 * - Call class constructor (same the `new` operator);
 	 * - Initialize the component properties using the name-value pairs given as the
 	 *   last parameter to this method;
 	 * - Call [[Initable::init|init]] if the class implements [[Initable]].
@@ -329,7 +329,6 @@ class Component
 	 * $model = Foo::create(1, 2, array('c' => 3));
 	 * // which is equivalent to the following lines:
 	 * $model = new Foo(1, 2);
-	 * $model->preinit();
 	 * $model->c = 3;
 	 * $model->init();
 	 * ~~~
diff --git a/framework/base/Initable.php b/framework/base/Initable.php
index 02b397b..c91cb03 100644
--- a/framework/base/Initable.php
+++ b/framework/base/Initable.php
@@ -13,9 +13,9 @@ namespace yii\base;
  * Initable is an interface indicating a class needs initialization to work properly.
  *
  * Initable requires a class to implement the [[init]] method.
- * When [[\Yii::createComponent]] is creating a new component instance, if the component
- * class implements Initable interface, the method will call its [[init]] method
- * after setting the initial values of the component properties.
+ * When [[\Yii::createComponent]] is being used to create a new component which implements
+ * Initable, it will call the [[init]] method after setting the initial values of the
+ * component properties.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
@@ -23,23 +23,10 @@ namespace yii\base;
 interface Initable
 {
 	/**
-	 * Pre-initializes this component.
-	 * This method is invoked by [[\Yii::createComponent]] after its creates the new
-	 * component instance, but BEFORE the component properties are initialized.
-	 *
-	 * You may implement this method to do work such as setting property default values.
-	 */
-	public function preinit();
-
-	/**
 	 * Initializes this component.
 	 * This method is invoked by [[\Yii::createComponent]] after its creates the new
 	 * component instance and initializes the component properties. In other words,
 	 * at this stage, the component has been fully configured.
-	 *
-	 * The default implementation calls [[behaviors]] and registers any available behaviors.
-	 * You may override this method with additional initialization logic (e.g. establish DB connection).
-	 * Make sure you call the parent implementation.
 	 */
 	public function init();
 }
diff --git a/framework/base/Model.php b/framework/base/Model.php
index a21efed..918a9df 100644
--- a/framework/base/Model.php
+++ b/framework/base/Model.php
@@ -50,18 +50,6 @@ class Model extends Component implements Initable, \IteratorAggregate, \ArrayAcc
 	}
 
 	/**
-	 * Pre-initializes this model.
-	 * This method is required by the [[Initable]] interface. It is invoked by
-	 * [[\Yii::createComponent]] after its creates the new model instance but
-	 * BEFORE the model properties are initialized.
-	 *
-	 * You may override this method to do work such as setting property default values.
-	 */
-	public function preinit()
-	{
-	}
-
-	/**
 	 * Initializes this model.
 	 *
 	 * This method is required by the [[Initable]] interface. It is invoked by [[\Yii::createComponent]]
diff --git a/framework/logging/EmailTarget.php b/framework/logging/EmailTarget.php
index c6a381a..3e9136f 100644
--- a/framework/logging/EmailTarget.php
+++ b/framework/logging/EmailTarget.php
@@ -1,146 +1,76 @@
 <?php
 /**
- * CEmailLogRoute class file.
+ * EmailTarget class file.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @link http://www.yiiframework.com/
- * @copyright Copyright &copy; 2008-2011 Yii Software LLC
+ * @copyright Copyright &copy; 2008-2012 Yii Software LLC
  * @license http://www.yiiframework.com/license/
  */
 
+namespace yii\logging;
+
 /**
- * CEmailLogRoute sends selected log messages to email addresses.
+ * EmailTarget sends selected log messages to the specified email addresses.
  *
- * The target email addresses may be specified via {@link setEmails emails} property.
- * Optionally, you may set the email {@link setSubject subject}, the
- * {@link setSentFrom sentFrom} address and any additional {@link setHeaders headers}.
+ * The target email addresses may be specified via [[emails]] property.
+ * Optionally, you may set the email [[subject]], [[sentFrom]] address and
+ * additional [[headers]].
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id: CEmailLogRoute.php 3001 2011-02-24 16:42:44Z alexander.makarow $
- * @package system.logging
- * @since 1.0
+ * @since 2.0
  */
-class CEmailLogRoute extends CLogRoute
+class EmailTarget extends Target
 {
 	/**
 	 * @var array list of destination email addresses.
 	 */
-	private $_email = array();
+	public $emails = array();
 	/**
 	 * @var string email subject
 	 */
-	private $_subject;
+	public $subject;
 	/**
-	 * @var string email sent from address
+	 * @var string email sent-from address
 	 */
-	private $_from;
+	public $sentFrom;
 	/**
 	 * @var array list of additional headers to use when sending an email.
 	 */
-	private $_headers = array();
+	public $headers = array();
 
 	/**
-	 * Sends log messages to specified email addresses.
-	 * @param array $logs list of log messages
+	 * Sends log [[messages]] to specified email addresses.
+	 * @param boolean $final whether this method is called at the end of the current application
 	 */
-	protected function processLogs($logs)
+	public function exportMessages($final)
 	{
-		$message = '';
-		foreach ($logs as $log)
-			$message .= $this->formatLogMessage($log[0], $log[1], $log[2], $log[3]);
-		$message = wordwrap($message, 70);
-		$subject = $this->getSubject();
-		if ($subject === null)
-			$subject = Yii::t('yii', 'Application Log');
-		foreach ($this->getEmails() as $email)
-			$this->sendEmail($email, $subject, $message);
+		$body = '';
+		foreach ($this->messages as $message) {
+			$body .= $this->formatMessage($message);
+		}
+		$body = wordwrap($body, 70);
+		$subject = $this->subject === null ? Yii::t('yii', 'Application Log') : $this->subject;
+		foreach ($this->emails as $email) {
+			$this->sendEmail($subject, $body, $email, $this->sentFrom, $this->headers);
+		}
+
+		$this->messages = array();
 	}
 
 	/**
 	 * Sends an email.
-	 * @param string $email single email address
 	 * @param string $subject email subject
-	 * @param string $message email content
-	 */
-	protected function sendEmail($email, $subject, $message)
-	{
-		$headers = $this->getHeaders();
-		if (($from = $this->getSentFrom()) !== null)
-			$headers[] = "From:  {$from}";
-		mail($email, $subject, $message, implode("\r\n", $headers));
-	}
-
-	/**
-	 * @return array list of destination email addresses
-	 */
-	public function getEmails()
-	{
-		return $this->_email;
-	}
-
-	/**
-	 * @param mixed $value list of destination email addresses. If the value is
-	 * a string, it is assumed to be comma-separated email addresses.
-	 */
-	public function setEmails($value)
-	{
-		if (is_array($value))
-			$this->_email = $value;
-		else
-			$this->_email = preg_split('/[\s,]+/', $value, -1, PREG_SPLIT_NO_EMPTY);
-	}
-
-	/**
-	 * @return string email subject. Defaults to CEmailLogRoute::DEFAULT_SUBJECT
-	 */
-	public function getSubject()
-	{
-		return $this->_subject;
-	}
-
-	/**
-	 * @param string $value email subject.
-	 */
-	public function setSubject($value)
-	{
-		$this->_subject = $value;
-	}
-
-	/**
-	 * @return string send from address of the email
-	 */
-	public function getSentFrom()
-	{
-		return $this->_from;
-	}
-
-	/**
-	 * @param string $value send from address of the email
-	 */
-	public function setSentFrom($value)
-	{
-		$this->_from = $value;
-	}
-
-	/**
-	 * @return array additional headers to use when sending an email.
-	 * @since 1.1.4
-	 */
-	public function getHeaders()
-	{
-		return $this->_headers;
-	}
-
-	/**
-	 * @param mixed $value list of additional headers to use when sending an email.
-	 * If the value is a string, it is assumed to be line break separated headers.
-	 * @since 1.1.4
+	 * @param string $body email body
+	 * @param string $sentTo sent-to email address
+	 * @param string $sentFrom sent-from email address
+	 * @param array $headers additional headers to be used when sending the email
 	 */
-	public function setHeaders($value)
+	protected function sendEmail($subject, $body, $sentTo, $sentFrom, $headers)
 	{
-		if (is_array($value))
-			$this->_headers = $value;
-		else
-			$this->_headers = preg_split('/\r\n|\n/', $value, -1, PREG_SPLIT_NO_EMPTY);
+		if ($sentFrom !== null) {
+			$headers[] = "From:  {$sentFrom}";
+		}
+		mail($email, $subject, $body, implode("\r\n", $headers));
 	}
 }
\ No newline at end of file
diff --git a/framework/logging/Filter.php b/framework/logging/Filter.php
deleted file mode 100644
index ab436e4..0000000
--- a/framework/logging/Filter.php
+++ /dev/null
@@ -1,107 +0,0 @@
-<?php
-/**
- * CLogFilter class file
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @link http://www.yiiframework.com/
- * @copyright Copyright &copy; 2008-2011 Yii Software LLC
- * @license http://www.yiiframework.com/license/
- */
-
-/**
- * CLogFilter preprocesses the logged messages before they are handled by a log route.
- *
- * CLogFilter is meant to be used by a log route to preprocess the logged messages
- * before they are handled by the route. The default implementation of CLogFilter
- * prepends additional context information to the logged messages. In particular,
- * by setting {@link logVars}, predefined PHP variables such as
- * $_SERVER, $_POST, etc. can be saved as a log message, which may help identify/debug
- * issues encountered.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id: CLogFilter.php 3204 2011-05-05 21:36:32Z alexander.makarow $
- * @package system.logging
- * @since 1.0.6
- */
-class CLogFilter extends CComponent
-{
-	/**
-	 * @var boolean whether to prefix each log message with the current user session ID.
-	 * Defaults to false.
-	 */
-	public $prefixSession = false;
-	/**
-	 * @var boolean whether to prefix each log message with the current user
-	 * {@link CWebUser::name name} and {@link CWebUser::id ID}. Defaults to false.
-	 */
-	public $prefixUser = false;
-	/**
-	 * @var boolean whether to log the current user name and ID. Defaults to true.
-	 */
-	public $logUser = true;
-	/**
-	 * @var array list of the PHP predefined variables that should be logged.
-	 * Note that a variable must be accessible via $GLOBALS. Otherwise it won't be logged.
-	 */
-	public $logVars = array('_GET', '_POST', '_FILES', '_COOKIE', '_SESSION', '_SERVER');
-
-
-	/**
-	 * Filters the given log messages.
-	 * This is the main method of CLogFilter. It processes the log messages
-	 * by adding context information, etc.
-	 * @param array $logs the log messages
-	 * @return array
-	 */
-	public function filter(&$logs)
-	{
-		if (!empty($logs))
-		{
-			if (($message = $this->getContext()) !== '')
-				array_unshift($logs, array($message, CLogger::LEVEL_INFO, 'application', YII_BEGIN_TIME));
-			$this->format($logs);
-		}
-		return $logs;
-	}
-
-	/**
-	 * Formats the log messages.
-	 * The default implementation will prefix each message with session ID
-	 * if {@link prefixSession} is set true. It may also prefix each message
-	 * with the current user's name and ID if {@link prefixUser} is true.
-	 * @param array $logs the log messages
-	 */
-	protected function format(&$logs)
-	{
-		$prefix = '';
-		if ($this->prefixSession && ($id = session_id()) !== '')
-			$prefix .= "[$id]";
-		if ($this->prefixUser && ($user = Yii::app()->getComponent('user', false)) !== null)
-			$prefix .= '[' . $user->getName() . '][' . $user->getId() . ']';
-		if ($prefix !== '')
-		{
-			foreach ($logs as &$log)
-				$log[0] = $prefix . ' ' . $log[0];
-		}
-	}
-
-	/**
-	 * Generates the context information to be logged.
-	 * The default implementation will dump user information, system variables, etc.
-	 * @return string the context information. If an empty string, it means no context information.
-	 */
-	protected function getContext()
-	{
-		$context = array();
-		if ($this->logUser && ($user = Yii::app()->getComponent('user', false)) !== null)
-			$context[] = 'User: ' . $user->getName() . ' (ID: ' . $user->getId() . ')';
-
-		foreach ($this->logVars as $name)
-		{
-			if (!empty($GLOBALS[$name]))
-				$context[] = "\$ {$name}=" . var_export($GLOBALS[$name], true);
-		}
-
-		return implode("\n\n", $context);
-	}
-}
\ No newline at end of file
diff --git a/framework/logging/Logger.php b/framework/logging/Logger.php
index e09092b..056a72e 100644
--- a/framework/logging/Logger.php
+++ b/framework/logging/Logger.php
@@ -38,20 +38,26 @@ class Logger extends \yii\base\Component
 	public $flushInterval = 1000;
 	/**
 	 * @var boolean this property will be passed as the parameter to [[flush]] when it is
-	 * called due to the [[flushInterval]] is reached. Defaults to false, meaning the flushed
-	 * messages are still kept in the memory by each log target. If this is true, they will
-	 * be exported to the actual storage medium (e.g. DB, email) defined by each log target.
+	 * called due to the [[flushInterval]] is reached. Defaults to true, meaning the flushed
+	 * messages will be exported to the actual storage medium (e.g. DB, email) defined by each
+	 * log target. If false, the flushed messages will be kept in the memory of each log target.
 	 * @see flushInterval
 	 */
-	public $autoExport = false;
+	public $autoExport = true;
 	/**
 	 * @var array logged messages. This property is mainly managed by [[log]] and [[flush]].
+	 * Each log message is of the following structure:
+	 *
+	 * ~~~
+	 * array(
+	 *   [0] => message (string)
+	 *   [1] => level (string)
+	 *   [2] => category (string)
+	 *   [3] => timestamp (float, obtained by microtime(true))
+	 * )
+	 * ~~~
 	 */
 	public $messages = array();
-	/**
-	 * @var array the profiling results (category, token => time in seconds)
-	 */
-	private $_timings;
 
 	/**
 	 * Logs an error message.
@@ -155,72 +161,24 @@ class Logger extends \yii\base\Component
 	}
 
 	/**
-	 * Retrieves log messages.
-	 *
-	 * Messages may be filtered by log levels and/or categories.
-	 * A level filter is specified by a list of levels separated by comma or space
-	 * (e.g. 'trace, error'). A category filter is similar to level filter
-	 * (e.g. 'system, system.web'). A difference is that in category filter
-	 * you can use pattern like 'system.*' to indicate all categories starting
-	 * with 'system'.
-	 *
-	 * If you do not specify level filter, it will bring back logs at all levels.
-	 * The same applies to category filter.
-	 *
-	 * Level filter and category filter are combinational, i.e., only messages
-	 * satisfying both filter conditions will be returned.
-	 *
-	 * @param string $levels level filter
-	 * @param string $categories category filter
-	 * @return array list of messages. Each array elements represents one message
-	 * with the following structure:
-	 * array(
-	 *   [0] => message (string)
-	 *   [1] => level (string)
-	 *   [2] => category (string)
-	 *   [3] => timestamp (float, obtained by microtime(true));
-	 */
-	public function getLogs($levels = '', $categories = '')
-	{
-		$this->_levels = preg_split('/[\s,]+/', strtolower($levels), -1, PREG_SPLIT_NO_EMPTY);
-		$this->_categories = preg_split('/[\s,]+/', strtolower($categories), -1, PREG_SPLIT_NO_EMPTY);
-		if (empty($levels) && empty($categories))
-			return $this->_logs;
-		elseif (empty($levels))
-			return array_values(array_filter(array_filter($this->_logs, array($this, 'filterByCategory'))));
-		elseif (empty($categories))
-			return array_values(array_filter(array_filter($this->_logs, array($this, 'filterByLevel'))));
-		else
-		{
-			$ret = array_values(array_filter(array_filter($this->_logs, array($this, 'filterByLevel'))));
-			return array_values(array_filter(array_filter($ret, array($this, 'filterByCategory'))));
-		}
-	}
-
-	/**
-	 * Filter function used by {@link getLogs}
-	 * @param array $value element to be filtered
-	 * @return array valid log, false if not.
+	 * Removes all recorded messages from the memory.
+	 * This method will raise an {@link onFlush} event.
+	 * The attached event handlers can process the log messages before they are removed.
+	 * @param boolean $export whether to notify log targets to export the filtered messages they have received.
 	 */
-	private function filterByCategory($value)
+	public function flush($export = false)
 	{
-		foreach ($this->_categories as $category)
-		{
-			$cat = strtolower($value[2]);
-			if ($cat === $category || (($c = rtrim($category, '.*')) !== $category && strpos($cat, $c) === 0))
-				return $value;
-		}
-		return false;
+		$this->onFlush(new \yii\base\Event($this, array('export' => $export, 'flush' => true)));
+		$this->messages = array();
 	}
 
 	/**
-	 * Filter function used by {@link getLogs}
-	 * @param array $value element to be filtered
-	 * @return array valid log, false if not.
+	 * Raises an `onFlush` event.
+	 * @param \yii\base\Event $event the event parameter
 	 */
-	private function filterByLevel($value)
+	public function onFlush($event)
 	{
-		return in_array(strtolower($value[1]), $this->_levels) ? $value : false;
+		$this->raiseEvent('onFlush', $event);
 	}
 
 	/**
@@ -237,36 +195,58 @@ class Logger extends \yii\base\Component
 
 	/**
 	 * Returns the profiling results.
-	 * The results may be filtered by token and/or category.
-	 * If no filter is specified, the returned results would be an array with each element
-	 * being `array($token, $category, $time)`.
-	 * If a filter is specified, the results would be an array of timings.
-	 * @param string $token token filter. Defaults to null, meaning not filtered by token.
-	 * @param string $category category filter. Defaults to null, meaning not filtered by category.
-	 * @param boolean $refresh whether to refresh the internal timing calculations. If false,
-	 * only the first time calling this method will the timings be calculated internally.
-	 * @return array the profiling results.
+	 *
+	 * By default, all profiling results will be returned. You may provide
+	 * `$categories` and `$excludeCategories` as parameters to retrieve the
+	 * results that you are interested in.
+	 *
+	 * @param array $categories list of categories that you are interested in.
+	 * You can use an asterisk at the end of a category to do a prefix match.
+	 * For example, 'yii\db\*' will match categories starting with 'yii\db\',
+	 * such as 'yii\db\dao\Connection'.
+	 * @param array $excludeCategories list of categories that you are interested in.
+	 * @return array the profiling results. Each array element has the following structure:
+	 *  `array($category, $time)`.
 	 */
-	public function getProfilingResults($token = null, $category = null, $refresh = false)
+	public function getProfiling($categories = array(), $excludeCategories = array())
 	{
-		if ($this->_timings === null || $refresh) {
-			$this->calculateTimings();
-		}
-		if ($token === null && $category === null) {
-			return $this->_timings;
+		$timings = $this->calculateTimings();
+		if (empty($categories) && empty($excludeCategories)) {
+			return $timings;
 		}
-		$results = array();
-		foreach ($this->_timings as $timing) {
-			if (($category === null || $timing[1] === $category) && ($token === null || $timing[0] === $token)) {
-				$results[] = $timing[2];
+
+		foreach ($timings as $i => $timing) {
+			$matched = empty($categories);
+			foreach ($categories as $category) {
+				$prefix = rtrim($category, '*');
+				if (strpos($timing[0], $prefix) === 0 && ($timing[0] === $category || $prefix !== $category)) {
+					$matched = true;
+					break;
+				}
+			}
+
+			if ($matched) {
+				foreach ($excludeCategories as $category) {
+					$prefix = rtrim($category, '*');
+					foreach ($timings as $i => $timing) {
+						if (strpos($timing[0], $prefix) === 0 && ($timing[0] === $category || $prefix !== $category)) {
+							$matched = false;
+							break;
+						}
+					}
+				}
+			}
+
+			if (!$matched) {
+				unset($timings[$i]);
 			}
 		}
-		return $results;
+		return array_values($timings);
 	}
 
 	private function calculateTimings()
 	{
-		$this->_timings = array();
+		$timings = array();
 
 		$stack = array();
 		foreach ($this->messages as $log) {
@@ -274,18 +254,16 @@ class Logger extends \yii\base\Component
 				continue;
 			}
 			list($message, $level, $category, $timestamp) = $log;
-			if (!strncasecmp($message, 'begin:', 6)) {
-				$log[0] = substr($message, 6);
+			if ($message === 'begin') {
 				$stack[] = $log;
 			}
-			elseif (!strncasecmp($message, 'end:', 4)) {
-				$token = substr($message, 4);
-				if (($last = array_pop($stack)) !== null && $last[0] === $token) {
-					$delta = $log[3] - $last[3];
-					$this->_timings[] = array($message, $category, $delta);
+			else { // $message === 'end'
+				if (($last = array_pop($stack)) !== null && $last[2] === $category) {
+					$delta = $timestamp - $last[3];
+					$timings[] = array($category, $delta);
 				}
 				else {
-					throw new \yii\base\Exception('Found a mismatching profiling block: ' . $token);
+					throw new \yii\base\Exception('Found a mismatching profiling block: ' . $category);
 				}
 			}
 		}
@@ -293,28 +271,10 @@ class Logger extends \yii\base\Component
 		$now = microtime(true);
 		while (($last = array_pop($stack)) !== null) {
 			$delta = $now - $last[3];
-			$this->_timings[] = array($last[0], $last[2], $delta);
+			$timings[] = array($last[2], $delta);
 		}
-	}
 
-	/**
-	 * Removes all recorded messages from the memory.
-	 * This method will raise an {@link onFlush} event.
-	 * The attached event handlers can process the log messages before they are removed.
-	 * @param boolean $export whether to notify log targets to export the filtered messages they have received.
-	 */
-	public function flush($export = false)
-	{
-		$this->onFlush(new \yii\base\Event($this, array('export' => $export)));
-		$this->messages = array();
+		return $timings;
 	}
 
-	/**
-	 * Raises an `onFlush` event.
-	 * @param \yii\base\Event $event the event parameter
-	 */
-	public function onFlush($event)
-	{
-		$this->raiseEvent('onFlush', $event);
-	}
 }
diff --git a/framework/logging/Router.php b/framework/logging/Router.php
index b0ad8c2..fa08a2c 100644
--- a/framework/logging/Router.php
+++ b/framework/logging/Router.php
@@ -125,11 +125,12 @@ class Router extends \yii\base\ApplicationComponent
 	 */
 	public function processMessages($event)
 	{
-		$logger = Yii::getLogger();
+		$messages = \Yii::getLogger()->messages;
 		$export = !isset($event->params['export']) || $event->params['export'];
+		$final = !isset($event-params['flush']) || !$event->params['flush'];
 		foreach ($this->_targets as $target) {
 			if ($target->enabled) {
-				$target->processMessages($logger, $export);
+				$target->processMessages($messages, $export, $final);
 			}
 		}
 	}
diff --git a/framework/logging/Target.php b/framework/logging/Target.php
index b14cfbe..4d20696 100644
--- a/framework/logging/Target.php
+++ b/framework/logging/Target.php
@@ -13,18 +13,15 @@ namespace yii\logging;
 /**
  * Target is the base class for all log target classes.
  *
- * A log target object retrieves log messages from a logger and sends it
- * somewhere, such as files, emails.
- * The messages being retrieved may be filtered first before being sent
- * to the destination. The filters include log level filter and log category filter.
- *
- * To specify level filter, set {@link levels} property,
- * which takes a string of comma-separated desired level names (e.g. 'Error, Debug').
- * To specify category filter, set {@link categories} property,
- * which takes a string of comma-separated desired category names (e.g. 'System.Web, System.IO').
+ * A log target object will filter the messages logged by [[Logger]] according
+ * to its [[levels]] and [[categories]] properties. It may also export the filtered
+ * messages to specific destination defined by the target, such as emails, files.
  *
  * Level filter and category filter are combinational, i.e., only messages
- * satisfying both filter conditions will they be returned.
+ * satisfying both filter conditions will they be returned.  Additionally, you
+ * may specify [[excludeCategories]]. If a message's category falls within the excluded
+ * categories, it will be filtered out, even if it passes the [[levels]] and
+ * [[categories]] filters.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
@@ -36,42 +33,57 @@ abstract class Target extends \yii\base\Component implements \yii\base\Initable
 	 */
 	public $enabled = true;
 	/**
-	 * @var string list of levels separated by comma or space. Defaults to empty, meaning all levels.
+	 * @var array list of message levels that this target is interested in. Defaults to empty, meaning all levels.
+	 */
+	public $levels = array();
+	/**
+	 * @var array list of message categories that this target is interested in. Defaults to empty, meaning all categories.
+	 * You can use an asterisk at the end of a category so that the category may be used to
+	 * match those categories sharing the same common prefix. For example, 'yii\db\*' will match
+	 * categories starting with 'yii\db\', such as 'yii\db\dao\Connection'.
+	 */
+	public $categories = array();
+	/**
+	 * @var array list of message categories that this target is NOT interested in. Defaults to empty, meaning no uninteresting messages.
+	 * If this property is not empty, then any category listed here will be excluded from [[categories]].
+	 * You can use an asterisk at the end of a category so that the category can be used to
+	 * match those categories sharing the same common prefix. For example, 'yii\db\*' will match
+	 * categories starting with 'yii\db\', such as 'yii\db\dao\Connection'.
+	 * @see categories
+	 */
+	public $excludeCategories = array();
+	/**
+	 * @var boolean whether to prefix each log message with the current session ID. Defaults to false.
 	 */
-	public $levels;
+	public $prefixSession = false;
 	/**
-	 * @var string list of categories separated by comma or space. Defaults to empty, meaning all categories.
+	 * @var boolean whether to prefix each log message with the current user name and ID. Defaults to false.
+	 * @see \yii\web\User
 	 */
-	public $categories;
+	public $prefixUser = false;
 	/**
-	 * @var string list of categories that should be excluded.
+	 * @var boolean whether to log a message containing the current user name and ID. Defaults to true.
+	 * @see \yii\web\User
 	 */
-	public $excludeCategories;
+	public $logUser = false;
 	/**
-	 * @var mixed the additional filter (eg {@link CLogFilter}) that can be applied to the log messages.
-	 * The value of this property will be passed to {@link Yii::createComponent} to create
-	 * a log filter object. As a result, this can be either a string representing the
-	 * filter class name or an array representing the filter configuration.
-	 * In general, the log filter class should be {@link CLogFilter} or a child class of it.
-	 * Defaults to null, meaning no filter will be used.
+	 * @var array list of the PHP predefined variables that should be logged in a message.
+	 * Note that a variable must be accessible via `$GLOBALS`. Otherwise it won't be logged.
+	 * Defaults to `array('_GET', '_POST', '_FILES', '_COOKIE', '_SESSION', '_SERVER')`.
 	 */
-	public $filter;
+	public $logVars = array('_GET', '_POST', '_FILES', '_COOKIE', '_SESSION', '_SERVER');
 	/**
-	 * @var array the messages that are collected so far by this log target.
+	 * @var array the messages that are retrieved from the logger so far by this log target.
 	 */
-	public $messages;
+	public $messages = array();
 
 	/**
-	 * Pre-initializes this component.
-	 * This method is required by the [[Initable]] interface. It is invoked by
-	 * [[\Yii::createComponent]] after its creates the new component instance but
-	 * BEFORE the component properties are initialized.
-	 *
-	 * You may override this method to do work such as setting property default values.
+	 * Exports log messages to a specific destination.
+	 * Child classes must implement this method. Note that you may need
+	 * to clean up [[messages]] in this method to avoid re-exporting messages.
+	 * @param boolean $final whether this method is called at the end of the current application
 	 */
-	public function preinit()
-	{
-	}
+	abstract public function exportMessages($final);
 
 	/**
 	 * Initializes this component.
@@ -83,89 +95,126 @@ abstract class Target extends \yii\base\Component implements \yii\base\Initable
 	}
 
 	/**
-	 * Formats a log message given different fields.
-	 * @param string $message message content
-	 * @param integer $level message level
-	 * @param string $category message category
-	 * @param integer $time timestamp
-	 * @return string formatted message
+	 * Processes the given log messages.
+	 * This method will filter the given messages with [[levels]] and [[categories]].
+	 * And if requested, it will also export the filtering result to specific medium (e.g. email).
+	 * @param array $messages log messages to be processed. See [[Logger::messages]] for the structure
+	 * of each message.
+	 * @param boolean $export whether to export the processing result
+	 * @param boolean $final whether this method is called at the end of the current application
 	 */
-	protected function formatMessage($message, $level, $category, $time)
+	public function processMessages($messages, $export, $final)
 	{
-		return @date('Y/m/d H:i:s', $time) . " [$level] [$category] $message\n";
+		$messages = $this->filterMessages($messages);
+		$this->messages = array_merge($this->messages, $messages);
+
+		if ($export && !empty($this->messages)) {
+			$this->prepareExport($final);
+			$this->exportMessages($final);
+		}
 	}
 
 	/**
-	 * Retrieves filtered log messages from logger for further processing.
-	 * @param CLogger $logger logger instance
-	 * @param boolean $processLogs whether to process the messages after they are collected from the logger
+	 * Prepares the [[messages]] for exporting.
+	 * This method will modify each message by prependding extra information
+	 * if [[prefixSession]] and/or [[prefixUser]] are set true.
+	 * It will also add an additional message showing context information if
+	 * [[logUser]] and/or [[logVars]] are set.
+	 * @param boolean $final whether this method is called at the end of the current application
 	 */
-	public function processMessages($logger, $export)
+	protected function prepareExport($final)
 	{
-		$messages = $logger->getLogs($this->levels, $this->categories);
-		$this->messages = empty($this->messages) ? $messages : array_merge($this->messages, $messages);
-		if ($processLogs && !empty($this->messages))
-		{
-			if ($this->filter !== null)
-				Yii::createComponent($this->filter)->filter($this->messages);
-			$this->processLogs($this->messages);
-			$this->messages = array();
+		$prefix = array();
+		if ($this->prefixSession && ($id = session_id()) !== '') {
+			$prefix[] = "[$id]";
+		}
+		if ($this->prefixUser && ($user = \Yii::app()->getComponent('user', false)) !== null) {
+			$prefix[] = '[' . $user->getName() . ']';
+			$prefix[] = '[' . $user->getId() . ']';
+		}
+		if ($prefix !== array()) {
+			$prefix = implode(' ', $prefix);
+			foreach ($this->messages as $i => $message) {
+				$this->messages[$i][0] = $prefix . ' ' . $this->messages[$i][0];
+			}
+		}
+		if ($final && ($context = $this->getContextMessage()) !== '') {
+			$this->messages[] = array($context, Logger::LEVEL_INFO, 'application', YII_BEGIN_TIME);
 		}
 	}
 
-	protected function filterMessages($levels = '', $categories = '')
+	/**
+	 * Generates the context information to be logged.
+	 * The default implementation will dump user information, system variables, etc.
+	 * @return string the context information. If an empty string, it means no context information.
+	 */
+	protected function getContextMessage()
 	{
-		$this->_levels = preg_split('/[\s,]+/', strtolower($levels), -1, PREG_SPLIT_NO_EMPTY);
-		$this->_categories = preg_split('/[\s,]+/', strtolower($categories), -1, PREG_SPLIT_NO_EMPTY);
-		if (empty($levels) && empty($categories))
-			return $this->_logs;
-		elseif (empty($levels))
-			return array_values(array_filter(array_filter($this->_logs, array($this, 'filterByCategory'))));
-		elseif (empty($categories))
-			return array_values(array_filter(array_filter($this->_logs, array($this, 'filterByLevel'))));
-		else
-		{
-			$ret = array_values(array_filter(array_filter($this->_logs, array($this, 'filterByLevel'))));
-			return array_values(array_filter(array_filter($ret, array($this, 'filterByCategory'))));
+		$context = array();
+		if ($this->logUser && ($user = \Yii::app()->getComponent('user', false)) !== null) {
+			$context[] = 'User: ' . $user->getName() . ' (ID: ' . $user->getId() . ')';
+		}
+
+		foreach ($this->logVars as $name) {
+			if (!empty($GLOBALS[$name])) {
+				$context[] = "\${$name} = " . var_export($GLOBALS[$name], true);
+			}
 		}
+
+		return implode("\n\n", $context);
 	}
 
 	/**
-	 * Filter function used by {@link getLogs}
-	 * @param array $value element to be filtered
-	 * @return array valid log, false if not.
+	 * Filters the given messages according to their categories and levels.
+	 * @param array $messages messages to be filtered
+	 * @return array the filtered messages.
+	 * @see filterByCategory
+	 * @see filterByLevel
 	 */
-	protected function filterByCategory($value)
+	protected function filterMessages($messages)
 	{
-		foreach ($this->_categories as $category)
-		{
-			$cat = strtolower($value[2]);
-			if ($cat === $category || (($c = rtrim($category, '.*')) !== $category && strpos($cat, $c) === 0))
-				return $value;
+		foreach ($messages as $i => $message) {
+			if (!empty($this->levels) && !in_array($message[1], $this->levels)) {
+				unset($messages[$i]);
+				continue;
+			}
+
+			$matched = empty($this->categories);
+			foreach ($this->categories as $category) {
+				$prefix = rtrim($category, '*');
+				if (strpos($message[2], $prefix) === 0 && ($message[2] === $category || $prefix !== $category)) {
+					$matched = true;
+					break;
+				}
+			}
+
+			if ($matched) {
+				foreach ($this->excludeCategories as $category) {
+					$prefix = rtrim($category, '*');
+					foreach ($messages as $i => $message) {
+						if (strpos($message[2], $prefix) === 0 && ($message[2] === $category || $prefix !== $category)) {
+							$matched = false;
+							break;
+						}
+					}
+				}
+			}
+
+			if (!$matched) {
+				unset($messages[$i]);
+			}
 		}
-		return false;
+		return $messages;
 	}
 
 	/**
-	 * Filter function used by {@link getLogs}
-	 * @param array $value element to be filtered
-	 * @return array valid log, false if not.
+	 * Formats a log message.
+	 * The message structure follows that in [[Logger::messages]].
+	 * @param array $message the log message to be formatted.
+	 * @return string the formatted message
 	 */
-	protected function filterByLevel($value)
+	public function formatMessage($message)
 	{
-		return in_array(strtolower($value[1]), $this->_levels) ? $value : false;
+		return @date('Y/m/d H:i:s', $message[3]) . " [{$message[1]}] [{$message[2]}] {$message[0]}\n";
 	}
-
-	/**
-	 * Processes log messages and sends them to specific destination.
-	 * Derived child classes must implement this method.
-	 * @param array $messages list of messages.  Each array elements represents one message
-	 * with the following structure:
-	 * array(
-	 *   [0] => message (string)
-	 *   [1] => level (string)
-	 *   [2] => category (string)
-	 *   [3] => timestamp (float, obtained by microtime(true));
-	 */
-	abstract protected function processLogs($messages);
 }