diff --git a/framework/YiiBase.php b/framework/YiiBase.php
index ce196bd..16ae1ff 100644
--- a/framework/YiiBase.php
+++ b/framework/YiiBase.php
@@ -531,11 +531,13 @@ class YiiBase
 	 */
 	public static function t($category, $message, $params = array(), $source = null, $language = null)
 	{
-		if (self::$app !== null)
+		// todo;
+		return $params !== array() ? strtr($message, $params) : $message;
+		if (self::$application !== null)
 		{
 			if ($source === null)
 				$source = $category === 'yii' ? 'coreMessages' : 'messages';
-			if (($source = self::$app->getComponent($source)) !== null)
+			if (($source = self::$application->getComponent($source)) !== null)
 				$message = $source->translate($category, $message, $language);
 		}
 		if ($params === array())
@@ -549,7 +551,7 @@ class YiiBase
 				if (strpos($message, '#') === false)
 				{
 					$chunks = explode('|', $message);
-					$expressions = self::$app->getLocale($language)->getPluralRules();
+					$expressions = self::$application->getLocale($language)->getPluralRules();
 					if ($n = min(count($chunks), count($expressions)))
 					{
 						for ($i = 0;$i < $n;$i++)
diff --git a/framework/console/Controller.php b/framework/console/Controller.php
index cb72764..210820b 100644
--- a/framework/console/Controller.php
+++ b/framework/console/Controller.php
@@ -29,12 +29,23 @@ use yii\base\Exception;
 class Controller extends \yii\base\Controller
 {
 	/**
+	 * This method is invoked when the request parameters do not satisfy the requirement of the specified action.
+	 * The default implementation will throw an exception.
+	 * @param Action $action the action being executed
+	 * @param Exception $exception the exception about the invalid parameters
+	 */
+	public function invalidActionParams($action, $exception)
+	{
+		echo "Error: " . $exception->getMessage() . "\n";
+		\Yii::$application->end(1);
+	}
+
+	/**
 	 * This method is invoked when extra parameters are provided to an action when it is executed.
 	 * The default implementation does nothing.
 	 * @param Action $action the action being executed
 	 * @param array $expected the expected action parameters (name => value)
 	 * @param array $actual the actual action parameters (name => value)
-	 * @throws Exception if any unrecognized parameters are provided
 	 */
 	public function extraActionParams($action, $expected, $actual)
 	{
@@ -42,9 +53,10 @@ class Controller extends \yii\base\Controller
 
 		$keys = array_diff(array_keys($actual), array_keys($expected));
 		if (!empty($keys)) {
-			throw new Exception(\Yii::t('yii', 'Unknown parameters: {params}', array(
+			echo "Error: " . \Yii::t('yii', 'Unknown parameters: {params}', array(
 				'{params}' => implode(', ', $keys),
-			)));
+			)) . "\n";
+			\Yii::$application->end(1);
 		}
 	}
 }
\ No newline at end of file
diff --git a/framework/console/commands/HelpController.php b/framework/console/commands/HelpController.php
index a7836bd..3fd99d0 100644
--- a/framework/console/commands/HelpController.php
+++ b/framework/console/commands/HelpController.php
@@ -9,31 +9,139 @@
 
 namespace yii\console\commands;
 
+use yii\base\Application;
+use yii\base\InlineAction;
+use yii\console\Controller;
+
 /**
- * HelpCommand represents a console help command.
+ * This command provides help information about console commands.
  *
- * HelpCommand displays the available command list or the help instructions
- * about a specific command.
+ * This command displays the available command list in
+ * the application or the detailed instructions about using
+ * a specific command.
  *
- * To use this command, enter the following on the command line:
+ * This command can be used as follows on command line:
  *
  * ~~~
  * yiic help [command name]
  * ~~~
  *
- * In the above, if the command name is not provided, it will display all
- * available commands.
- *
- * @property string $help The command description.
+ * In the above, if the command name is not provided, all
+ * available commands will be displayed.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
-class HelpController extends \yii\console\Controller
+class HelpController extends Controller
 {
+	/**
+	 * Displays available commands or the detailed information
+	 * about a particular command. For example,
+	 *
+	 * ~~~
+	 * yiic help          # list available commands
+	 * yiic help message  # display help info about "message"
+	 * ~~~
+	 *
+	 * @param array $args additional anonymous command line arguments.
+	 * You may provide a command-name to display its detailed information.
+	 * @return integer the exit status
+	 */
 	public function actionIndex($args = array())
 	{
-		echo "Yii console command helper (based on Yii v" . \Yii::getVersion() . ").\n";
+		if (empty($args)) {
+			$status = $this->helpIndex();
+		} else {
+			$result = \Yii::$application->createController($args[0]);
+			if ($result === false) {
+				echo "Unknown command: " . $args[0] . "\n";
+				return 1;
+			}
+
+			list($controller, $action) = $result;
+
+			if ($action === '') {
+				$status = $this->helpController($controller);
+			} else {
+				$status = $this->helpAction($controller, $action);
+			}
+		}
+		return $status;
+	}
+
+	/**
+	 * Returns all available command names.
+	 * @return array all available command names
+	 */
+	public function getCommands()
+	{
+		$commands = $this->getModuleCommands(\Yii::$application);
+		sort($commands);
+		return array_unique($commands);
+	}
+
+	/**
+	 * Returns all available actions of the specified controller.
+	 * @param Controller $controller the controller instance
+	 * @return array all available action IDs.
+	 */
+	public function getActions($controller)
+	{
+		$actions = array_keys($controller->actions);
+		$class = new \ReflectionClass($controller);
+		foreach ($class->getMethods() as $method) {
+			$name = $method->getName();
+			if ($method->isPublic() && !$method->isStatic() && strpos($name, 'action') === 0) {
+				$actions[] = lcfirst(substr($name, 6));
+			}
+		}
+		sort($actions);
+		return array_unique($actions);
+	}
+
+	/**
+	 * Returns available commands of a specified module.
+	 * @param \yii\base\Module $module the module instance
+	 * @return array the available command names
+	 */
+	protected function getModuleCommands($module)
+	{
+		if ($module instanceof Application) {
+			$prefix = '';
+		} else {
+			$prefix = $module->getUniqueId() . '/';
+		}
+
+		$commands = array();
+		foreach (array_keys($module->controllers) as $id) {
+			$commands[] = $prefix . $id;
+		}
+
+		foreach ($module->getModules() as $id => $child) {
+			if (($child = $module->getModule($id)) === null) {
+				continue;
+			}
+			foreach ($this->getModuleCommands($child) as $command) {
+				$commands[] = $prefix . $id . '/' . $command;
+			}
+		}
+
+		$files = scandir($module->getControllerPath());
+		foreach ($files as $file) {
+			if(strcmp(substr($file,-14),'Controller.php') === 0 && is_file($file)) {
+				$commands[] = $prefix . lcfirst(substr(basename($file), 0, -14));
+			}
+		}
+
+		return $commands;
+	}
+
+	/**
+	 * Displays all available commands.
+	 * @return integer the exit status
+	 */
+	protected function helpIndex()
+	{
 		$commands = $this->getCommands();
 		if ($commands !== array()) {
 			echo "\n    Usage: yiic <command-name> [...options...]\n\n";
@@ -46,40 +154,202 @@ class HelpController extends \yii\console\Controller
 		} else {
 			echo "\nNo commands are found.\n";
 		}
+		return 0;
 	}
 
-	protected function getCommands()
+	/**
+	 * Displays the overall information of the command.
+	 * @param Controller $controller the controller instance
+	 * @return integer the exit status
+	 */
+	protected function helpController($controller)
 	{
-		$commands = $this->getModuleCommands(\Yii::$application);
-		sort($commands);
-		return array_unique($commands);
+		$class = new \ReflectionClass($controller);
+		$comment = strtr(trim(preg_replace('/^\s*\**( |\t)?/m', '', trim($class->getDocComment(), '/'))), "\r", '');
+		if (preg_match('/^\s*@\w+/m', $comment, $matches, PREG_OFFSET_CAPTURE)) {
+			$comment = trim(substr($comment, 0, $matches[0][1]));
+		}
+
+		if ($comment !== '') {
+			echo "\nDESCRIPTION";
+			echo "\n-----------\n\n";
+			echo $comment . "\n";
+		}
+
+		$options = $this->getGlobalOptions($class, $controller);
+		if ($options !== array()) {
+			echo "\nGLOBAL OPTIONS";
+			echo "\n--------------\n\n";
+			foreach ($options as $name => $description) {
+				echo " --$name";
+				if ($description != '') {
+					echo ": $description\n";
+				}
+			}
+			echo "\n";
+		}
+
+		$actions = $this->getActions($controller);
+		if ($actions !== array()) {
+			echo "\nSUB-COMMANDS";
+			echo "\n------------\n\n";
+			$prefix = $controller->getUniqueId();
+			foreach ($actions as $action) {
+				if ($controller->defaultAction === $action) {
+					echo " * $prefix/$action (default)\n";
+				} else {
+					echo " * $prefix/$action\n";
+				}
+			}
+			echo "\n";
+		}
+
+		return 0;
 	}
 
 	/**
-	 * @param \yii\base\Module $module
-	 * @return array
+	 * Displays the detailed information of a command action.
+	 * @param Controller $controller the controller instance
+	 * @param string $actionID action ID
+	 * @return integer the exit status
 	 */
-	protected function getModuleCommands($module)
+	protected function helpAction($controller, $actionID)
 	{
-		if ($module === null) {
-			return array();
+		$action = $controller->createAction($actionID);
+		if ($action === null) {
+			echo "Unknown sub-command: " . $controller->getUniqueId() . "/$actionID\n";
+			return 1;
+		}
+		if ($action instanceof InlineAction) {
+			$method = new \ReflectionMethod($controller, 'action' . $action->id);
+		} else {
+			$method = new \ReflectionMethod($action, 'run');
+		}
+		$comment = strtr(trim(preg_replace('/^\s*\**( |\t)?/m', '', trim($method->getDocComment(), '/'))), "\r", '');
+		if (preg_match('/^\s*@\w+/m', $comment, $matches, PREG_OFFSET_CAPTURE)) {
+			$meta = substr($comment, $matches[0][1]);
+			$comment = trim(substr($comment, 0, $matches[0][1]));
+		} else {
+			$meta = '';
 		}
 
-		$commands = array_keys($module->controllers);
+		if ($comment !== '') {
+			echo "\nDESCRIPTION";
+			echo "\n-----------\n\n";
+			echo $comment . "\n";
+		}
 
-		foreach ($module->getModules() as $id => $module) {
-			foreach ($this->getModuleCommands($module->getModule($id)) as $command) {
-				$commands[] = $command;
+		$options = $this->getOptions($method, $meta);
+		if ($options !== array()) {
+			echo "\nOPTIONS";
+			echo "\n-------\n\n";
+			foreach ($options as $name => $description) {
+				echo " --$name";
+				if ($description != '') {
+					echo ": $description\n";
+				}
 			}
+			echo "\n";
 		}
 
-		$files = scandir($module->getControllerPath());
-		foreach ($files as $file) {
-			if(strcmp(substr($file,-14),'Controller.php') === 0 && is_file($file)) {
-				$commands[] = lcfirst(substr(basename($file), 0, -14));
+		return 0;
+	}
+
+	/**
+	 * @param \ReflectionMethod $method
+	 * @param string $meta
+	 * @return array
+	 */
+	protected function getOptions($method, $meta)
+	{
+		$params = $method->getParameters();
+		$tags = preg_split('/^\s*@/m', $meta, -1, PREG_SPLIT_NO_EMPTY);
+		$options = array();
+		$count = 0;
+		foreach ($tags as $tag) {
+			$parts = preg_split('/\s+/', trim($tag), 2);
+			if ($parts[0] === 'param' && isset($params[$count])) {
+				$param = $params[$count];
+				$comment = isset($parts[1]) ? $parts[1] : '';
+				if (preg_match('/^([^\s]+)\s+(\$\w+\s+)?(.*)/s', $comment, $matches)) {
+					$type = $matches[1];
+					$doc = $matches[3];
+				} else {
+					$type = $comment;
+					$doc = '';
+				}
+				$comment = $type === '' ? '' : ($type . ', ');
+				if ($param->isDefaultValueAvailable()) {
+					$value = $param->getDefaultValue();
+					if (!is_array($value)) {
+						$comment .= 'optional (defaults to ' . var_export($value, true) . ').';
+					} else {
+						$comment .= 'optional.';
+					}
+				} else {
+					$comment .= 'required.';
+				}
+				if (trim($doc) !== '') {
+					$comment .= "\n" . preg_replace("/^/m", "     ", $doc);
+				}
+				$options[$param->getName()] = $comment;
+				$count++;
+			}
+		}
+		if ($count < count($params)) {
+			for ($i = $count; $i < count($params); ++$i) {
+				$options[$params[$i]->getName()] = '';
 			}
 		}
 
-		return $commands;
+		ksort($options);
+		return $options;
+	}
+
+	/**
+	 * @param \ReflectionClass $class
+	 * @param Controller $controller
+	 * @return array
+	 */
+	protected function getGlobalOptions($class, $controller)
+	{
+		$options = array();
+		foreach ($class->getProperties() as $property) {
+			if (!$property->isPublic() || $property->isStatic() || $property->getDeclaringClass()->getName() !== get_class($controller)) {
+				continue;
+			}
+			$name = $property->getName();
+			$comment = strtr(trim(preg_replace('/^\s*\**( |\t)?/m', '', trim($property->getDocComment(), '/'))), "\r", '');
+			if (preg_match('/^\s*@\w+/m', $comment, $matches, PREG_OFFSET_CAPTURE)) {
+				$meta = substr($comment, $matches[0][1]);
+			} else {
+				$meta = '';
+			}
+			$tags = preg_split('/^\s*@/m', $meta, -1, PREG_SPLIT_NO_EMPTY);
+			foreach ($tags as $tag) {
+				$parts = preg_split('/\s+/', trim($tag), 2);
+				$comment = isset($parts[1]) ? $parts[1] : '';
+				if ($parts[0] === 'var' || $parts[0] === 'property') {
+					if (preg_match('/^([^\s]+)(\s+.*)?/s', $comment, $matches)) {
+						$type = $matches[1];
+						$doc = trim($matches[2]);
+					} else {
+						$type = $comment;
+						$doc = '';
+					}
+					$comment = $type === '' ? '' : ($type . '.');
+					if (trim($doc) !== '') {
+						$comment .= "\n" . preg_replace("/^/m", "     ", $doc);
+					}
+					$options[$name] = $comment;
+					break;
+				}
+			}
+			if (!isset($options[$name])) {
+				$options[$name] = '';
+			}
+		}
+		ksort($options);
+		return $options;
 	}
 }
\ No newline at end of file
diff --git a/framework/util/ReflectionHelper.php b/framework/util/ReflectionHelper.php
index 8920af6..e858619 100644
--- a/framework/util/ReflectionHelper.php
+++ b/framework/util/ReflectionHelper.php
@@ -54,7 +54,7 @@ class ReflectionHelper
 			} elseif ($param->isDefaultValueAvailable()) {
 				$ps[$name] = $param->getDefaultValue();
 			} else {
-				throw new Exception(\Yii::t('yii', 'Missing required parameter "{name}".', array('{name' => $name)));
+				throw new Exception(\Yii::t('yii', 'Missing required parameter "{name}".', array('{name}' => $name)));
 			}
 		}
 		return $ps;