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diff --git a/docs/internals/exception_hierarchy.vsd b/docs/internals/exception_hierarchy.vsd
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diff --git a/tests/unit/framework/rbac/ManagerTestBase.php b/tests/unit/framework/rbac/ManagerTestBase.php
new file mode 100644
index 0000000..03d5354
--- /dev/null
+++ b/tests/unit/framework/rbac/ManagerTestBase.php
@@ -0,0 +1,248 @@
+<?php
+
+namespace yiiunit\framework\rbac;
+
+use yii\rbac\Assignment;
+use yii\rbac\Item;
+use yiiunit\TestCase;
+
+abstract class ManagerTestBase extends TestCase
+{
+	/** @var \yii\rbac\PhpManager|\yii\rbac\DbManager */
+	protected $auth;
+
+	public function testCreateItem()
+	{
+		$type = Item::TYPE_TASK;
+		$name = 'editUser';
+		$description = 'edit a user';
+		$bizRule = 'checkUserIdentity()';
+		$data = array(1, 2, 3);
+		$item = $this->auth->createItem($name, $type, $description, $bizRule, $data);
+		$this->assertTrue($item instanceof Item);
+		$this->assertEquals($item->type, $type);
+		$this->assertEquals($item->name, $name);
+		$this->assertEquals($item->description, $description);
+		$this->assertEquals($item->bizRule, $bizRule);
+		$this->assertEquals($item->data, $data);
+
+		// test shortcut
+		$name2 = 'createUser';
+		$item2 = $this->auth->createRole($name2, $description, $bizRule, $data);
+		$this->assertEquals($item2->type, Item::TYPE_ROLE);
+
+		// test adding an item with the same name
+		$this->setExpectedException('Exception');
+		$this->auth->createItem($name, $type, $description, $bizRule, $data);
+	}
+
+	public function testGetItem()
+	{
+		$this->assertTrue($this->auth->getItem('readPost') instanceof Item);
+		$this->assertTrue($this->auth->getItem('reader') instanceof Item);
+		$this->assertNull($this->auth->getItem('unknown'));
+	}
+
+	public function testRemoveAuthItem()
+	{
+		$this->assertTrue($this->auth->getItem('updatePost') instanceof Item);
+		$this->assertTrue($this->auth->removeItem('updatePost'));
+		$this->assertNull($this->auth->getItem('updatePost'));
+		$this->assertFalse($this->auth->removeItem('updatePost'));
+	}
+
+	public function testChangeItemName()
+	{
+		$item = $this->auth->getItem('readPost');
+		$this->assertTrue($item instanceof Item);
+		$this->assertTrue($this->auth->hasItemChild('reader', 'readPost'));
+		$item->name = 'readPost2';
+		$this->assertNull($this->auth->getItem('readPost'));
+		$this->assertEquals($this->auth->getItem('readPost2'), $item);
+		$this->assertFalse($this->auth->hasItemChild('reader', 'readPost'));
+		$this->assertTrue($this->auth->hasItemChild('reader', 'readPost2'));
+	}
+
+	public function testAddItemChild()
+	{
+		$this->auth->addItemChild('createPost', 'updatePost');
+
+		// test adding upper level item to lower one
+		$this->setExpectedException('Exception');
+		$this->auth->addItemChild('readPost', 'reader');
+	}
+
+	public function testAddItemChild2()
+	{
+		// test adding inexistent items
+		$this->setExpectedException('Exception');
+		$this->assertFalse($this->auth->addItemChild('createPost2', 'updatePost'));
+	}
+
+	public function testRemoveItemChild()
+	{
+		$this->assertTrue($this->auth->hasItemChild('reader', 'readPost'));
+		$this->assertTrue($this->auth->removeItemChild('reader', 'readPost'));
+		$this->assertFalse($this->auth->hasItemChild('reader', 'readPost'));
+		$this->assertFalse($this->auth->removeItemChild('reader', 'readPost'));
+	}
+
+	public function testGetItemChildren()
+	{
+		$this->assertEquals(array(), $this->auth->getItemChildren('readPost'));
+		$children = $this->auth->getItemChildren('author');
+		$this->assertEquals(3, count($children));
+		$this->assertTrue(reset($children) instanceof Item);
+	}
+
+	public function testAssign()
+	{
+		$auth = $this->auth->assign('new user', 'createPost', 'rule', 'data');
+		$this->assertTrue($auth instanceof Assignment);
+		$this->assertEquals($auth->userId, 'new user');
+		$this->assertEquals($auth->itemName, 'createPost');
+		$this->assertEquals($auth->bizRule, 'rule');
+		$this->assertEquals($auth->data, 'data');
+
+		$this->setExpectedException('Exception');
+		$this->auth->assign('new user', 'createPost2', 'rule', 'data');
+	}
+
+	public function testRevoke()
+	{
+		$this->assertTrue($this->auth->isAssigned('author B', 'author'));
+		$auth = $this->auth->getAssignment('author B', 'author');
+		$this->assertTrue($auth instanceof Assignment);
+		$this->assertTrue($this->auth->revoke('author B', 'author'));
+		$this->assertFalse($this->auth->isAssigned('author B', 'author'));
+		$this->assertFalse($this->auth->revoke('author B', 'author'));
+	}
+
+	public function testGetAssignments()
+	{
+		$this->auth->assign('author B', 'deletePost');
+		$auths = $this->auth->getAssignments('author B');
+		$this->assertEquals(2, count($auths));
+		$this->assertTrue(reset($auths) instanceof Assignment);
+	}
+
+	public function testGetItems()
+	{
+		$this->assertEquals(count($this->auth->getRoles()), 4);
+		$this->assertEquals(count($this->auth->getOperations()), 4);
+		$this->assertEquals(count($this->auth->getTasks()), 1);
+		$this->assertEquals(count($this->auth->getItems()), 9);
+
+		$this->assertEquals(count($this->auth->getItems('author B', null)), 1);
+		$this->assertEquals(count($this->auth->getItems('author C', null)), 0);
+		$this->assertEquals(count($this->auth->getItems('author B', Item::TYPE_ROLE)), 1);
+		$this->assertEquals(count($this->auth->getItems('author B', Item::TYPE_OPERATION)), 0);
+	}
+
+	public function testClearAll()
+	{
+		$this->auth->clearAll();
+		$this->assertEquals(count($this->auth->getRoles()), 0);
+		$this->assertEquals(count($this->auth->getOperations()), 0);
+		$this->assertEquals(count($this->auth->getTasks()), 0);
+		$this->assertEquals(count($this->auth->getItems()), 0);
+		$this->assertEquals(count($this->auth->getAssignments('author B')), 0);
+	}
+
+	public function testClearAssignments()
+	{
+		$this->auth->clearAssignments();
+		$this->assertEquals(count($this->auth->getAssignments('author B')), 0);
+	}
+
+	public function testDetectLoop()
+	{
+		$this->setExpectedException('Exception');
+		$this->auth->addItemChild('readPost', 'readPost');
+	}
+
+	public function testExecuteBizRule()
+	{
+		$this->assertTrue($this->auth->executeBizRule(null, array(), null));
+		$this->assertTrue($this->auth->executeBizRule('return 1==true;', array(), null));
+		$this->assertTrue($this->auth->executeBizRule('return $params[0]==$params[1];', array(1, '1'), null));
+		$this->assertFalse($this->auth->executeBizRule('invalid', array(), null));
+	}
+
+	public function testCheckAccess()
+	{
+		$results = array(
+			'reader A' => array(
+				'createPost' => false,
+				'readPost' => true,
+				'updatePost' => false,
+				'updateOwnPost' => false,
+				'deletePost' => false,
+			),
+			'author B' => array(
+				'createPost' => true,
+				'readPost' => true,
+				'updatePost' => true,
+				'updateOwnPost' => true,
+				'deletePost' => false,
+			),
+			'editor C' => array(
+				'createPost' => false,
+				'readPost' => true,
+				'updatePost' => true,
+				'updateOwnPost' => false,
+				'deletePost' => false,
+			),
+			'admin D' => array(
+				'createPost' => true,
+				'readPost' => true,
+				'updatePost' => true,
+				'updateOwnPost' => false,
+				'deletePost' => true,
+			),
+		);
+
+		$params = array('authorID' => 'author B');
+
+		foreach (array('reader A', 'author B', 'editor C', 'admin D') as $user) {
+			$params['userID'] = $user;
+			foreach (array('createPost', 'readPost', 'updatePost', 'updateOwnPost', 'deletePost') as $operation) {
+				$result = $this->auth->checkAccess($user, $operation, $params);
+				$this->assertEquals($results[$user][$operation], $result);
+			}
+		}
+	}
+
+	protected function prepareData()
+	{
+		$this->auth->createOperation('createPost', 'create a post');
+		$this->auth->createOperation('readPost', 'read a post');
+		$this->auth->createOperation('updatePost', 'update a post');
+		$this->auth->createOperation('deletePost', 'delete a post');
+
+		$task = $this->auth->createTask('updateOwnPost', 'update a post by author himself', 'return $params["authorID"]==$params["userID"];');
+		$task->addChild('updatePost');
+
+		$role = $this->auth->createRole('reader');
+		$role->addChild('readPost');
+
+		$role = $this->auth->createRole('author');
+		$role->addChild('reader');
+		$role->addChild('createPost');
+		$role->addChild('updateOwnPost');
+
+		$role = $this->auth->createRole('editor');
+		$role->addChild('reader');
+		$role->addChild('updatePost');
+
+		$role = $this->auth->createRole('admin');
+		$role->addChild('editor');
+		$role->addChild('author');
+		$role->addChild('deletePost');
+
+		$this->auth->assign('reader A', 'reader');
+		$this->auth->assign('author B', 'author');
+		$this->auth->assign('editor C', 'editor');
+		$this->auth->assign('admin D', 'admin');
+	}
+}
diff --git a/tests/unit/framework/rbac/PhpManagerTest.php b/tests/unit/framework/rbac/PhpManagerTest.php
new file mode 100644
index 0000000..69fdd41
--- /dev/null
+++ b/tests/unit/framework/rbac/PhpManagerTest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace yiiunit\framework\rbac;
+
+use Yii;
+use yii\rbac\PhpManager;
+
+require_once(__DIR__ . '/ManagerTestBase.php');
+
+class PhpManagerTest extends ManagerTestBase
+{
+	public function setUp()
+	{
+		$authFile = Yii::$app->getRuntimePath() . '/rbac.php';
+		@unlink($authFile);
+		$this->auth = new PhpManager;
+		$this->auth->authFile = $authFile;
+		$this->auth->init();
+		$this->prepareData();
+	}
+
+	public function tearDown()
+	{
+		@unlink($this->auth->authFile);
+	}
+
+	public function testSaveLoad()
+	{
+		$this->auth->save();
+		$this->auth->clearAll();
+		$this->auth->load();
+		$this->testCheckAccess();
+	}
+}
diff --git a/yii/base/Application.php b/yii/base/Application.php
index ac7cc6a..2e068ef 100644
--- a/yii/base/Application.php
+++ b/yii/base/Application.php
@@ -305,12 +305,12 @@ class Application extends Module
 	}
 
 	/**
-	 * @return null|Component
-	 * @todo
+	 * Returns the auth manager for this application.
+	 * @return \yii\rbac\Manager the auth manager for this application.
 	 */
 	public function getAuthManager()
 	{
-		return $this->getComponent('auth');
+		return $this->getComponent('authManager');
 	}
 
 	/**
diff --git a/yii/rbac/Assignment.php b/yii/rbac/Assignment.php
new file mode 100644
index 0000000..5b6a607
--- /dev/null
+++ b/yii/rbac/Assignment.php
@@ -0,0 +1,106 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\rbac;
+
+use Yii;
+use yii\base\Object;
+
+/**
+ * Assignment represents an assignment of a role to a user.
+ * It includes additional assignment information such as [[bizRule]] and [[data]].
+ * Do not create a Assignment instance using the 'new' operator.
+ * Instead, call [[Manager::assign()]].
+ *
+ * @property mixed $userId User ID (see [[User::id]]).
+ * @property string $itemName The authorization item name.
+ * @property string $bizRule The business rule associated with this assignment.
+ * @property mixed $data Additional data for this assignment.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @since 2.0
+ */
+class Assignment extends Object
+{
+	private $_auth;
+	private $_userId;
+	private $_itemName;
+	private $_bizRule;
+	private $_data;
+
+	/**
+	 * Constructor.
+	 * @param Manager $auth the authorization manager
+	 * @param mixed $userId user ID (see [[User::id]])
+	 * @param string $itemName authorization item name
+	 * @param string $bizRule the business rule associated with this assignment
+	 * @param mixed $data additional data for this assignment
+	 */
+	public function __construct($auth, $userId, $itemName, $bizRule = null, $data = null)
+	{
+		$this->_auth = $auth;
+		$this->_userId = $userId;
+		$this->_itemName = $itemName;
+		$this->_bizRule = $bizRule;
+		$this->_data = $data;
+	}
+
+	/**
+	 * @return mixed user ID (see [[User::id]])
+	 */
+	public function getUserId()
+	{
+		return $this->_userId;
+	}
+
+	/**
+	 * @return string the authorization item name
+	 */
+	public function getItemName()
+	{
+		return $this->_itemName;
+	}
+
+	/**
+	 * @return string the business rule associated with this assignment
+	 */
+	public function getBizRule()
+	{
+		return $this->_bizRule;
+	}
+
+	/**
+	 * @param string $value the business rule associated with this assignment
+	 */
+	public function setBizRule($value)
+	{
+		if ($this->_bizRule !== $value) {
+			$this->_bizRule = $value;
+			$this->_auth->saveAssignment($this);
+		}
+	}
+
+	/**
+	 * @return mixed additional data for this assignment
+	 */
+	public function getData()
+	{
+		return $this->_data;
+	}
+
+	/**
+	 * @param mixed $value additional data for this assignment
+	 */
+	public function setData($value)
+	{
+		if ($this->_data !== $value) {
+			$this->_data = $value;
+			$this->_auth->saveAssignment($this);
+		}
+	}
+}
diff --git a/yii/rbac/DbManager.php b/yii/rbac/DbManager.php
new file mode 100644
index 0000000..f3658b2
--- /dev/null
+++ b/yii/rbac/DbManager.php
@@ -0,0 +1,573 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\rbac;
+
+use Yii;
+use yii\db\Connection;
+use yii\db\Query;
+use yii\db\Expression;
+use yii\base\Exception;
+use yii\base\InvalidConfigException;
+use yii\base\InvalidCallException;
+use yii\base\InvalidParamException;
+
+/**
+ * DbManager represents an authorization manager that stores authorization information in database.
+ *
+ * The database connection is specified by [[db]]. And the database schema
+ * should be as described in "framework/rbac/*.sql". You may change the names of
+ * the three tables used to store the authorization data by setting [[itemTable]],
+ * [[itemChildTable]] and [[assignmentTable]].
+ *
+ * @property array $authItems The authorization items of the specific type.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @since 2.0
+ */
+class DbManager extends Manager
+{
+	/**
+	 * @var Connection|string the DB connection object or the application component ID of the DB connection.
+	 * After the DbManager object is created, if you want to change this property, you should only assign it
+	 * with a DB connection object.
+	 */
+	public $db = 'db';
+	/**
+	 * @var string the name of the table storing authorization items. Defaults to 'tbl_auth_item'.
+	 */
+	public $itemTable = 'tbl_auth_item';
+	/**
+	 * @var string the name of the table storing authorization item hierarchy. Defaults to 'tbl_auth_item_child'.
+	 */
+	public $itemChildTable = 'tbl_auth_item_child';
+	/**
+	 * @var string the name of the table storing authorization item assignments. Defaults to 'tbl_auth_assignment'.
+	 */
+	public $assignmentTable = 'tbl_auth_assignment';
+
+	private $_usingSqlite;
+
+	/**
+	 * Initializes the application component.
+	 * This method overrides the parent implementation by establishing the database connection.
+	 */
+	public function init()
+	{
+		if (is_string($this->db)) {
+			$this->db = Yii::$app->getComponent($this->db);
+		}
+		if (!$this->db instanceof Connection) {
+			throw new InvalidConfigException("DbManager::db must be either a DB connection instance or the application component ID of a DB connection.");
+		}
+		$this->_usingSqlite = !strncmp($this->db->getDriverName(), 'sqlite', 6);
+		parent::init();
+	}
+
+	/**
+	 * Performs access check for the specified user.
+	 * @param mixed $userId the user ID. This should can be either an integer or a string representing
+	 * the unique identifier of a user. See [[User::id]].
+	 * @param string $itemName the name of the operation that need access check
+	 * @param array $params name-value pairs that would be passed to biz rules associated
+	 * with the tasks and roles assigned to the user. A param with name 'userId' is added to this array,
+	 * which holds the value of `$userId`.
+	 * @return boolean whether the operations can be performed by the user.
+	 */
+	public function checkAccess($userId, $itemName, $params = array())
+	{
+		$assignments = $this->getAssignments($userId);
+		return $this->checkAccessRecursive($userId, $itemName, $params, $assignments);
+	}
+
+	/**
+	 * Performs access check for the specified user.
+	 * This method is internally called by [[checkAccess()]].
+	 * @param mixed $userId the user ID. This should can be either an integer or a string representing
+	 * the unique identifier of a user. See [[User::id]].
+	 * @param string $itemName the name of the operation that need access check
+	 * @param array $params name-value pairs that would be passed to biz rules associated
+	 * with the tasks and roles assigned to the user. A param with name 'userId' is added to this array,
+	 * which holds the value of `$userId`.
+	 * @param Assignment[] $assignments the assignments to the specified user
+	 * @return boolean whether the operations can be performed by the user.
+	 */
+	protected function checkAccessRecursive($userId, $itemName, $params, $assignments)
+	{
+		if (($item = $this->getItem($itemName)) === null) {
+			return false;
+		}
+		Yii::trace('Checking permission: ' . $item->getName(), __METHOD__);
+		if (!isset($params['userId'])) {
+			$params['userId'] = $userId;
+		}
+		if ($this->executeBizRule($item->getBizRule(), $params, $item->getData())) {
+			if (in_array($itemName, $this->defaultRoles)) {
+				return true;
+			}
+			if (isset($assignments[$itemName])) {
+				$assignment = $assignments[$itemName];
+				if ($this->executeBizRule($assignment->getBizRule(), $params, $assignment->getData())) {
+					return true;
+				}
+			}
+			$query = new Query;
+			$parents = $query->select(array('parent'))
+				->from($this->itemChildTable)
+				->where(array('child' => $itemName))
+				->createCommand($this->db)
+				->queryColumn();
+			foreach ($parents as $parent) {
+				if ($this->checkAccessRecursive($userId, $parent, $params, $assignments)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Adds an item as a child of another item.
+	 * @param string $itemName the parent item name
+	 * @param string $childName the child item name
+	 * @return boolean whether the item is added successfully
+	 * @throws Exception if either parent or child doesn't exist.
+	 * @throws InvalidCallException if a loop has been detected.
+	 */
+	public function addItemChild($itemName, $childName)
+	{
+		if ($itemName === $childName) {
+			throw new Exception("Cannot add '$itemName' as a child of itself.");
+		}
+		$query = new Query;
+		$rows = $query->from($this->itemTable)
+			->where(array('or', 'name=:name1', 'name=:name2'), array(
+				':name1' => $itemName,
+				':name2' => $childName
+			))
+			->createCommand($this->db)
+			->queryAll();
+		if (count($rows) == 2) {
+			if ($rows[0]['name'] === $itemName) {
+				$parentType = $rows[0]['type'];
+				$childType = $rows[1]['type'];
+			} else {
+				$childType = $rows[0]['type'];
+				$parentType = $rows[1]['type'];
+			}
+			$this->checkItemChildType($parentType, $childType);
+			if ($this->detectLoop($itemName, $childName)) {
+				throw new InvalidCallException("Cannot add '$childName' as a child of '$itemName'. A loop has been detected.");
+			}
+			$this->db->createCommand()
+				->insert($this->itemChildTable, array(
+					'parent' => $itemName,
+					'child' => $childName,
+				));
+			return true;
+		} else {
+			throw new Exception("Either '$itemName' or '$childName' does not exist.");
+		}
+	}
+
+	/**
+	 * Removes a child from its parent.
+	 * Note, the child item is not deleted. Only the parent-child relationship is removed.
+	 * @param string $itemName the parent item name
+	 * @param string $childName the child item name
+	 * @return boolean whether the removal is successful
+	 */
+	public function removeItemChild($itemName, $childName)
+	{
+		return $this->db->createCommand()
+			->delete($this->itemChildTable, array(
+				'parent' => $itemName,
+				'child' => $childName
+			)) > 0;
+	}
+
+	/**
+	 * Returns a value indicating whether a child exists within a parent.
+	 * @param string $itemName the parent item name
+	 * @param string $childName the child item name
+	 * @return boolean whether the child exists
+	 */
+	public function hasItemChild($itemName, $childName)
+	{
+		$query = new Query;
+		return $query->select(array('parent'))
+			->from($this->itemChildTable)
+			->where(array(
+				'parent' => $itemName,
+				'child' => $childName
+			))
+			->createCommand($this->db)
+			->queryScalar() !== false;
+	}
+
+	/**
+	 * Returns the children of the specified item.
+	 * @param mixed $names the parent item name. This can be either a string or an array.
+	 * The latter represents a list of item names.
+	 * @return Item[] all child items of the parent
+	 */
+	public function getItemChildren($names)
+	{
+		$query = new Query;
+		$rows = $query->select(array('name', 'type', 'description', 'bizrule', 'data'))
+			->from(array(
+				$this->itemTable,
+				$this->itemChildTable
+			))
+			->where(array('parent' => $names, 'name' => new Expression('child')))
+			->createCommand($this->db)
+			->queryAll();
+		$children = array();
+		foreach ($rows as $row) {
+			if (($data = @unserialize($row['data'])) === false) {
+				$data = null;
+			}
+			$children[$row['name']] = new Item($this, $row['name'], $row['type'], $row['description'], $row['bizrule'], $data);
+		}
+		return $children;
+	}
+
+	/**
+	 * Assigns an authorization item to a user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @param string $bizRule the business rule to be executed when [[checkAccess()]] is called
+	 * for this particular authorization item.
+	 * @param mixed $data additional data associated with this assignment
+	 * @return Assignment the authorization assignment information.
+	 * @throws InvalidParamException if the item does not exist or if the item has already been assigned to the user
+	 */
+	public function assign($userId, $itemName, $bizRule = null, $data = null)
+	{
+		if ($this->usingSqlite() && $this->getItem($itemName) === null) {
+			throw new InvalidParamException("The item '$itemName' does not exist.");
+		}
+		$this->db->createCommand()
+			->insert($this->assignmentTable, array(
+				'user_id' => $userId,
+				'item_name' => $itemName,
+				'bizrule' => $bizRule,
+				'data' => serialize($data)
+			));
+		return new Assignment($this, $userId, $itemName, $bizRule, $data);
+	}
+
+	/**
+	 * Revokes an authorization assignment from a user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @return boolean whether removal is successful
+	 */
+	public function revoke($userId, $itemName)
+	{
+		return $this->db->createCommand()
+			->delete($this->assignmentTable, array(
+				'user_id' => $userId,
+				'item_name' => $itemName
+			)) > 0;
+	}
+
+	/**
+	 * Returns a value indicating whether the item has been assigned to the user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @return boolean whether the item has been assigned to the user.
+	 */
+	public function isAssigned($itemName, $userId)
+	{
+		$query = new Query;
+		return $query->select(array('item_name'))
+			->from($this->assignmentTable)
+			->where(array(
+				'user_id' => $userId,
+				'item_name' => $itemName
+			))
+			->createCommand($this->db)
+			->queryScalar() !== false;
+	}
+
+	/**
+	 * Returns the item assignment information.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @return Assignment the item assignment information. Null is returned if
+	 * the item is not assigned to the user.
+	 */
+	public function getAssignment($userId, $itemName)
+	{
+		$query = new Query;
+		$row = $query->from($this->assignmentTable)
+			->where(array(
+				'user_id' => $userId,
+				'item_name' => $itemName
+			))
+			->createCommand($this->db)
+			->queryRow();
+		if ($row !== false) {
+			if (($data = @unserialize($row['data'])) === false) {
+				$data = null;
+			}
+			return new Assignment($this, $row['user_id'], $row['item_name'], $row['bizrule'], $data);
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * Returns the item assignments for the specified user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @return Assignment[] the item assignment information for the user. An empty array will be
+	 * returned if there is no item assigned to the user.
+	 */
+	public function getAssignments($userId)
+	{
+		$query = new Query;
+		$rows = $query->from($this->assignmentTable)
+			->where(array('user_id' => $userId))
+			->createCommand($this->db)
+			->queryAll();
+		$assignments = array();
+		foreach ($rows as $row) {
+			if (($data = @unserialize($row['data'])) === false) {
+				$data = null;
+			}
+			$assignments[$row['item_name']] = new Assignment($this, $row['user_id'], $row['item_name'], $row['bizrule'], $data);
+		}
+		return $assignments;
+	}
+
+	/**
+	 * Saves the changes to an authorization assignment.
+	 * @param Assignment $assignment the assignment that has been changed.
+	 */
+	public function saveAssignment($assignment)
+	{
+		$this->db->createCommand()
+			->update($this->assignmentTable, array(
+				'bizrule' => $assignment->getBizRule(),
+				'data' => serialize($assignment->getData()),
+			), array(
+				'user_id' => $assignment->getUserId(),
+				'item_name' => $assignment->getItemName()
+			));
+	}
+
+	/**
+	 * Returns the authorization items of the specific type and user.
+	 * @param mixed $userId the user ID. Defaults to null, meaning returning all items even if
+	 * they are not assigned to a user.
+	 * @param integer $type the item type (0: operation, 1: task, 2: role). Defaults to null,
+	 * meaning returning all items regardless of their type.
+	 * @return Item[] the authorization items of the specific type.
+	 */
+	public function getItems($userId = null, $type = null)
+	{
+		$query = new Query;
+		if ($userId === null && $type === null) {
+			$command = $query->from($this->itemTable)
+				->createCommand($this->db);
+		} elseif ($userId === null) {
+			$command = $query->from($this->itemTable)
+				->where(array('type' => $type))
+				->createCommand($this->db);
+		} elseif ($type === null) {
+			$command = $query->select(array('name', 'type', 'description', 't1.bizrule', 't1.data'))
+				->from(array(
+					$this->itemTable . ' t1',
+					$this->assignmentTable . ' t2'
+				))
+				->where(array('user_id' => $userId, 'name' => new Expression('item_name')))
+				->createCommand($this->db);
+		} else {
+			$command = $query->select('name', 'type', 'description', 't1.bizrule', 't1.data')
+				->from(array(
+					$this->itemTable . ' t1',
+					$this->assignmentTable . ' t2'
+				))
+				->where(array(
+					'user_id' => $userId,
+					'type' => $type,
+					'name' => new Expression('item_name'),
+				))
+				->createCommand($this->db);
+		}
+		$items = array();
+		foreach ($command->queryAll() as $row) {
+			if (($data = @unserialize($row['data'])) === false) {
+				$data = null;
+			}
+			$items[$row['name']] = new Item($this, $row['name'], $row['type'], $row['description'], $row['bizrule'], $data);
+		}
+		return $items;
+	}
+
+	/**
+	 * Creates an authorization item.
+	 * An authorization item represents an action permission (e.g. creating a post).
+	 * It has three types: operation, task and role.
+	 * Authorization items form a hierarchy. Higher level items inheirt permissions representing
+	 * by lower level items.
+	 * @param string $name the item name. This must be a unique identifier.
+	 * @param integer $type the item type (0: operation, 1: task, 2: role).
+	 * @param string $description description of the item
+	 * @param string $bizRule business rule associated with the item. This is a piece of
+	 * PHP code that will be executed when [[checkAccess()]] is called for the item.
+	 * @param mixed $data additional data associated with the item.
+	 * @return Item the authorization item
+	 * @throws Exception if an item with the same name already exists
+	 */
+	public function createItem($name, $type, $description = '', $bizRule = null, $data = null)
+	{
+		$this->db->createCommand()
+			->insert($this->itemTable, array(
+				'name' => $name,
+				'type' => $type,
+				'description' => $description,
+				'bizrule' => $bizRule,
+				'data' => serialize($data)
+			));
+		return new Item($this, $name, $type, $description, $bizRule, $data);
+	}
+
+	/**
+	 * Removes the specified authorization item.
+	 * @param string $name the name of the item to be removed
+	 * @return boolean whether the item exists in the storage and has been removed
+	 */
+	public function removeItem($name)
+	{
+		if ($this->usingSqlite()) {
+			$this->db->createCommand()
+				->delete($this->itemChildTable, array('or', 'parent=:name1', 'child=:name2'), array(
+					':name1' => $name,
+					':name2' => $name
+				));
+			$this->db->createCommand()->delete($this->assignmentTable, array('item_name' => $name));
+		}
+		return $this->db->createCommand()->delete($this->itemTable, array('name' => $name)) > 0;
+	}
+
+	/**
+	 * Returns the authorization item with the specified name.
+	 * @param string $name the name of the item
+	 * @return Item the authorization item. Null if the item cannot be found.
+	 */
+	public function getItem($name)
+	{
+		$query = new Query;
+		$row = $query->from($this->itemTable)
+			->where(array('name' => $name))
+			->createCommand($this->db)
+			->queryRow();
+
+		if ($row !== false) {
+			if (($data = @unserialize($row['data'])) === false) {
+				$data = null;
+			}
+			return new Item($this, $row['name'], $row['type'], $row['description'], $row['bizrule'], $data);
+		} else
+			return null;
+	}
+
+	/**
+	 * Saves an authorization item to persistent storage.
+	 * @param Item $item the item to be saved.
+	 * @param string $oldName the old item name. If null, it means the item name is not changed.
+	 */
+	public function saveItem($item, $oldName = null)
+	{
+		if ($this->usingSqlite() && $oldName !== null && $item->getName() !== $oldName) {
+			$this->db->createCommand()
+				->update($this->itemChildTable, array(
+					'parent' => $item->getName(),
+				), array(
+					'parent' => $oldName,
+				));
+			$this->db->createCommand()
+				->update($this->itemChildTable, array(
+					'child' => $item->getName(),
+				), array(
+					'child' => $oldName,
+				));
+			$this->db->createCommand()
+				->update($this->assignmentTable, array(
+					'item_name' => $item->getName(),
+				), array(
+					'item_name' => $oldName,
+				));
+		}
+
+		$this->db->createCommand()
+			->update($this->itemTable, array(
+				'name' => $item->getName(),
+				'type' => $item->getType(),
+				'description' => $item->getDescription(),
+				'bizrule' => $item->getBizRule(),
+				'data' => serialize($item->getData()),
+			), array(
+				'name' => $oldName === null ? $item->getName() : $oldName,
+			));
+	}
+
+	/**
+	 * Saves the authorization data to persistent storage.
+	 */
+	public function save()
+	{
+	}
+
+	/**
+	 * Removes all authorization data.
+	 */
+	public function clearAll()
+	{
+		$this->clearAssignments();
+		$this->db->createCommand()->delete($this->itemChildTable);
+		$this->db->createCommand()->delete($this->itemTable);
+	}
+
+	/**
+	 * Removes all authorization assignments.
+	 */
+	public function clearAssignments()
+	{
+		$this->db->createCommand()->delete($this->assignmentTable);
+	}
+
+	/**
+	 * Checks whether there is a loop in the authorization item hierarchy.
+	 * @param string $itemName parent item name
+	 * @param string $childName the name of the child item that is to be added to the hierarchy
+	 * @return boolean whether a loop exists
+	 */
+	protected function detectLoop($itemName, $childName)
+	{
+		if ($childName === $itemName) {
+			return true;
+		}
+		foreach ($this->getItemChildren($childName) as $child) {
+			if ($this->detectLoop($itemName, $child->getName())) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * @return boolean whether the database is a SQLite database
+	 */
+	protected function usingSqlite()
+	{
+		return $this->_usingSqlite;
+	}
+}
diff --git a/yii/rbac/Item.php b/yii/rbac/Item.php
new file mode 100644
index 0000000..ef56a53
--- /dev/null
+++ b/yii/rbac/Item.php
@@ -0,0 +1,275 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\rbac;
+
+use Yii;
+use yii\base\Object;
+
+/**
+ * Item represents an authorization item.
+ * An authorization item can be an operation, a task or a role.
+ * They form an authorization hierarchy. Items on higher levels of the hierarchy
+ * inherit the permissions represented by items on lower levels.
+ * A user may be assigned one or several authorization items (called [[Assignment]] assignments).
+ * He can perform an operation only when it is among his assigned items.
+ *
+ * @property Manager $authManager The authorization manager.
+ * @property integer $type The authorization item type. This could be 0 (operation), 1 (task) or 2 (role).
+ * @property string $name The item name.
+ * @property string $description The item description.
+ * @property string $bizRule The business rule associated with this item.
+ * @property mixed $data The additional data associated with this item.
+ * @property array $children All child items of this item.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @since 2.0
+ */
+class Item extends Object
+{
+	const TYPE_OPERATION = 0;
+	const TYPE_TASK = 1;
+	const TYPE_ROLE = 2;
+
+	private $_auth;
+	private $_type;
+	private $_name;
+	private $_description;
+	private $_bizRule;
+	private $_data;
+
+	/**
+	 * Constructor.
+	 * @param Manager $auth authorization manager
+	 * @param string $name authorization item name
+	 * @param integer $type authorization item type. This can be 0 (operation), 1 (task) or 2 (role).
+	 * @param string $description the description
+	 * @param string $bizRule the business rule associated with this item
+	 * @param mixed $data additional data for this item
+	 */
+	public function __construct($auth, $name, $type, $description = '', $bizRule = null, $data = null)
+	{
+		$this->_type = (int)$type;
+		$this->_auth = $auth;
+		$this->_name = $name;
+		$this->_description = $description;
+		$this->_bizRule = $bizRule;
+		$this->_data = $data;
+	}
+
+	/**
+	 * Checks to see if the specified item is within the hierarchy starting from this item.
+	 * This method is expected to be internally used by the actual implementations
+	 * of the [[Manager::checkAccess()]].
+	 * @param string $itemName the name of the item to be checked
+	 * @param array $params the parameters to be passed to business rule evaluation
+	 * @return boolean whether the specified item is within the hierarchy starting from this item.
+	 */
+	public function checkAccess($itemName, $params = array())
+	{
+		Yii::trace('Checking permission: ' . $this->_name, __METHOD__);
+		if ($this->_auth->executeBizRule($this->_bizRule, $params, $this->_data)) {
+			if ($this->_name == $itemName) {
+				return true;
+			}
+			foreach ($this->_auth->getItemChildren($this->_name) as $item) {
+				if ($item->checkAccess($itemName, $params)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * @return Manager the authorization manager
+	 */
+	public function getManager()
+	{
+		return $this->_auth;
+	}
+
+	/**
+	 * @return integer the authorization item type. This could be 0 (operation), 1 (task) or 2 (role).
+	 */
+	public function getType()
+	{
+		return $this->_type;
+	}
+
+	/**
+	 * @return string the item name
+	 */
+	public function getName()
+	{
+		return $this->_name;
+	}
+
+	/**
+	 * @param string $value the item name
+	 */
+	public function setName($value)
+	{
+		if ($this->_name !== $value) {
+			$oldName = $this->_name;
+			$this->_name = $value;
+			$this->_auth->saveItem($this, $oldName);
+		}
+	}
+
+	/**
+	 * @return string the item description
+	 */
+	public function getDescription()
+	{
+		return $this->_description;
+	}
+
+	/**
+	 * @param string $value the item description
+	 */
+	public function setDescription($value)
+	{
+		if ($this->_description !== $value) {
+			$this->_description = $value;
+			$this->_auth->saveItem($this);
+		}
+	}
+
+	/**
+	 * @return string the business rule associated with this item
+	 */
+	public function getBizRule()
+	{
+		return $this->_bizRule;
+	}
+
+	/**
+	 * @param string $value the business rule associated with this item
+	 */
+	public function setBizRule($value)
+	{
+		if ($this->_bizRule !== $value) {
+			$this->_bizRule = $value;
+			$this->_auth->saveItem($this);
+		}
+	}
+
+	/**
+	 * @return mixed the additional data associated with this item
+	 */
+	public function getData()
+	{
+		return $this->_data;
+	}
+
+	/**
+	 * @param mixed $value the additional data associated with this item
+	 */
+	public function setData($value)
+	{
+		if ($this->_data !== $value) {
+			$this->_data = $value;
+			$this->_auth->saveItem($this);
+		}
+	}
+
+	/**
+	 * Adds a child item.
+	 * @param string $name the name of the child item
+	 * @return boolean whether the item is added successfully
+	 * @throws \yii\base\Exception if either parent or child doesn't exist or if a loop has been detected.
+	 * @see Manager::addItemChild
+	 */
+	public function addChild($name)
+	{
+		return $this->_auth->addItemChild($this->_name, $name);
+	}
+
+	/**
+	 * Removes a child item.
+	 * Note, the child item is not deleted. Only the parent-child relationship is removed.
+	 * @param string $name the child item name
+	 * @return boolean whether the removal is successful
+	 * @see Manager::removeItemChild
+	 */
+	public function removeChild($name)
+	{
+		return $this->_auth->removeItemChild($this->_name, $name);
+	}
+
+	/**
+	 * Returns a value indicating whether a child exists
+	 * @param string $name the child item name
+	 * @return boolean whether the child exists
+	 * @see Manager::hasItemChild
+	 */
+	public function hasChild($name)
+	{
+		return $this->_auth->hasItemChild($this->_name, $name);
+	}
+
+	/**
+	 * Returns the children of this item.
+	 * @return Item[] all child items of this item.
+	 * @see Manager::getItemChildren
+	 */
+	public function getChildren()
+	{
+		return $this->_auth->getItemChildren($this->_name);
+	}
+
+	/**
+	 * Assigns this item to a user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $bizRule the business rule to be executed when [[checkAccess()]] is called
+	 * for this particular authorization item.
+	 * @param mixed $data additional data associated with this assignment
+	 * @return Assignment the authorization assignment information.
+	 * @throws \yii\base\Exception if the item has already been assigned to the user
+	 * @see Manager::assign
+	 */
+	public function assign($userId, $bizRule = null, $data = null)
+	{
+		return $this->_auth->assign($userId, $this->_name, $bizRule, $data);
+	}
+
+	/**
+	 * Revokes an authorization assignment from a user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @return boolean whether removal is successful
+	 * @see Manager::revoke
+	 */
+	public function revoke($userId)
+	{
+		return $this->_auth->revoke($userId, $this->_name);
+	}
+
+	/**
+	 * Returns a value indicating whether this item has been assigned to the user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @return boolean whether the item has been assigned to the user.
+	 * @see Manager::isAssigned
+	 */
+	public function isAssigned($userId)
+	{
+		return $this->_auth->isAssigned($userId, $this->_name);
+	}
+
+	/**
+	 * Returns the item assignment information.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @return Assignment the item assignment information. Null is returned if
+	 * this item is not assigned to the user.
+	 * @see Manager::getAssignment
+	 */
+	public function getAssignment($userId)
+	{
+		return $this->_auth->getAssignment($userId, $this->_name);
+	}
+}
diff --git a/yii/rbac/Manager.php b/yii/rbac/Manager.php
new file mode 100644
index 0000000..5c3c4f6
--- /dev/null
+++ b/yii/rbac/Manager.php
@@ -0,0 +1,312 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\rbac;
+
+use Yii;
+use yii\base\Component;
+use yii\base\InvalidParamException;
+
+/**
+ * Manager is the base class for authorization manager classes.
+ *
+ * Manager extends [[Component]] and implements some methods
+ * that are common among authorization manager classes.
+ *
+ * Manager together with its concrete child classes implement the Role-Based
+ * Access Control (RBAC).
+ *
+ * The main idea is that permissions are organized as a hierarchy of
+ * [[Item]] authorization items. Items on higer level inherit the permissions
+ * represented by items on lower level. And roles are simply top-level authorization items
+ * that may be assigned to individual users. A user is said to have a permission
+ * to do something if the corresponding authorization item is inherited by one of his roles.
+ *
+ * Using authorization manager consists of two aspects. First, the authorization hierarchy
+ * and assignments have to be established. Manager and its child classes
+ * provides APIs to accomplish this task. Developers may need to develop some GUI
+ * so that it is more intuitive to end-users. Second, developers call [[Manager::checkAccess()]]
+ * at appropriate places in the application code to check if the current user
+ * has the needed permission for an operation.
+ *
+ * @property array $roles Roles (name=>Item).
+ * @property array $tasks Tasks (name=>Item).
+ * @property array $operations Operations (name=>Item).
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @since 2.0
+ */
+abstract class Manager extends Component
+{
+	/**
+	 * @var boolean Enable error reporting for bizRules.
+	 */
+	public $showErrors = false;
+
+	/**
+	 * @var array list of role names that are assigned to all users implicitly.
+	 * These roles do not need to be explicitly assigned to any user.
+	 * When calling [[checkAccess()]], these roles will be checked first.
+	 * For performance reason, you should minimize the number of such roles.
+	 * A typical usage of such roles is to define an 'authenticated' role and associate
+	 * it with a biz rule which checks if the current user is authenticated.
+	 * And then declare 'authenticated' in this property so that it can be applied to
+	 * every authenticated user.
+	 */
+	public $defaultRoles = array();
+
+	/**
+	 * Creates a role.
+	 * This is a shortcut method to [[Manager::createItem()]].
+	 * @param string $name the item name
+	 * @param string $description the item description.
+	 * @param string $bizRule the business rule associated with this item
+	 * @param mixed $data additional data to be passed when evaluating the business rule
+	 * @return Item the authorization item
+	 */
+	public function createRole($name, $description = '', $bizRule = null, $data = null)
+	{
+		return $this->createItem($name, Item::TYPE_ROLE, $description, $bizRule, $data);
+	}
+
+	/**
+	 * Creates a task.
+	 * This is a shortcut method to [[Manager::createItem()]].
+	 * @param string $name the item name
+	 * @param string $description the item description.
+	 * @param string $bizRule the business rule associated with this item
+	 * @param mixed $data additional data to be passed when evaluating the business rule
+	 * @return Item the authorization item
+	 */
+	public function createTask($name, $description = '', $bizRule = null, $data = null)
+	{
+		return $this->createItem($name, Item::TYPE_TASK, $description, $bizRule, $data);
+	}
+
+	/**
+	 * Creates an operation.
+	 * This is a shortcut method to [[Manager::createItem()]].
+	 * @param string $name the item name
+	 * @param string $description the item description.
+	 * @param string $bizRule the business rule associated with this item
+	 * @param mixed $data additional data to be passed when evaluating the business rule
+	 * @return Item the authorization item
+	 */
+	public function createOperation($name, $description = '', $bizRule = null, $data = null)
+	{
+		return $this->createItem($name, Item::TYPE_OPERATION, $description, $bizRule, $data);
+	}
+
+	/**
+	 * Returns roles.
+	 * This is a shortcut method to [[Manager::getItems()]].
+	 * @param mixed $userId the user ID. If not null, only the roles directly assigned to the user
+	 * will be returned. Otherwise, all roles will be returned.
+	 * @return Item[] roles (name=>AuthItem)
+	 */
+	public function getRoles($userId = null)
+	{
+		return $this->getItems($userId, Item::TYPE_ROLE);
+	}
+
+	/**
+	 * Returns tasks.
+	 * This is a shortcut method to [[Manager::getItems()]].
+	 * @param mixed $userId the user ID. If not null, only the tasks directly assigned to the user
+	 * will be returned. Otherwise, all tasks will be returned.
+	 * @return Item[] tasks (name=>AuthItem)
+	 */
+	public function getTasks($userId = null)
+	{
+		return $this->getItems($userId, Item::TYPE_TASK);
+	}
+
+	/**
+	 * Returns operations.
+	 * This is a shortcut method to [[Manager::getItems()]].
+	 * @param mixed $userId the user ID. If not null, only the operations directly assigned to the user
+	 * will be returned. Otherwise, all operations will be returned.
+	 * @return Item[] operations (name=>AuthItem)
+	 */
+	public function getOperations($userId = null)
+	{
+		return $this->getItems($userId, Item::TYPE_OPERATION);
+	}
+
+	/**
+	 * Executes the specified business rule.
+	 * @param string $bizRule the business rule to be executed.
+	 * @param array $params parameters passed to [[Manager::checkAccess()]].
+	 * @param mixed $data additional data associated with the authorization item or assignment.
+	 * @return boolean whether the business rule returns true.
+	 * If the business rule is empty, it will still return true.
+	 */
+	public function executeBizRule($bizRule, $params, $data)
+	{
+		return $bizRule === '' || $bizRule === null || ($this->showErrors ? eval($bizRule) != 0 : @eval($bizRule) != 0);
+	}
+
+	/**
+	 * Checks the item types to make sure a child can be added to a parent.
+	 * @param integer $parentType parent item type
+	 * @param integer $childType child item type
+	 * @throws InvalidParamException if the item cannot be added as a child due to its incompatible type.
+	 */
+	protected function checkItemChildType($parentType, $childType)
+	{
+		static $types = array('operation', 'task', 'role');
+		if ($parentType < $childType) {
+			throw new InvalidParamException("Cannot add an item of type '$types[$childType]' to an item of type '$types[$parentType]'.");
+		}
+	}
+
+	/**
+	 * Performs access check for the specified user.
+	 * @param mixed $userId the user ID. This should be either an integer or a string representing
+	 * the unique identifier of a user. See [[User::id]].
+	 * @param string $itemName the name of the operation that we are checking access to
+	 * @param array $params name-value pairs that would be passed to biz rules associated
+	 * with the tasks and roles assigned to the user.
+	 * @return boolean whether the operations can be performed by the user.
+	 */
+	abstract public function checkAccess($userId, $itemName, $params = array());
+
+	/**
+	 * Creates an authorization item.
+	 * An authorization item represents an action permission (e.g. creating a post).
+	 * It has three types: operation, task and role.
+	 * Authorization items form a hierarchy. Higher level items inheirt permissions representing
+	 * by lower level items.
+	 * @param string $name the item name. This must be a unique identifier.
+	 * @param integer $type the item type (0: operation, 1: task, 2: role).
+	 * @param string $description description of the item
+	 * @param string $bizRule business rule associated with the item. This is a piece of
+	 * PHP code that will be executed when [[checkAccess()]] is called for the item.
+	 * @param mixed $data additional data associated with the item.
+	 * @throws \yii\base\Exception if an item with the same name already exists
+	 * @return Item the authorization item
+	 */
+	abstract public function createItem($name, $type, $description = '', $bizRule = null, $data = null);
+	/**
+	 * Removes the specified authorization item.
+	 * @param string $name the name of the item to be removed
+	 * @return boolean whether the item exists in the storage and has been removed
+	 */
+	abstract public function removeItem($name);
+	/**
+	 * Returns the authorization items of the specific type and user.
+	 * @param mixed $userId the user ID. Defaults to null, meaning returning all items even if
+	 * they are not assigned to a user.
+	 * @param integer $type the item type (0: operation, 1: task, 2: role). Defaults to null,
+	 * meaning returning all items regardless of their type.
+	 * @return Item[] the authorization items of the specific type.
+	 */
+	abstract public function getItems($userId = null, $type = null);
+	/**
+	 * Returns the authorization item with the specified name.
+	 * @param string $name the name of the item
+	 * @return Item the authorization item. Null if the item cannot be found.
+	 */
+	abstract public function getItem($name);
+	/**
+	 * Saves an authorization item to persistent storage.
+	 * @param Item $item the item to be saved.
+	 * @param string $oldName the old item name. If null, it means the item name is not changed.
+	 */
+	abstract public function saveItem($item, $oldName = null);
+
+	/**
+	 * Adds an item as a child of another item.
+	 * @param string $itemName the parent item name
+	 * @param string $childName the child item name
+	 * @throws \yii\base\Exception if either parent or child doesn't exist or if a loop has been detected.
+	 */
+	abstract public function addItemChild($itemName, $childName);
+	/**
+	 * Removes a child from its parent.
+	 * Note, the child item is not deleted. Only the parent-child relationship is removed.
+	 * @param string $itemName the parent item name
+	 * @param string $childName the child item name
+	 * @return boolean whether the removal is successful
+	 */
+	abstract public function removeItemChild($itemName, $childName);
+	/**
+	 * Returns a value indicating whether a child exists within a parent.
+	 * @param string $itemName the parent item name
+	 * @param string $childName the child item name
+	 * @return boolean whether the child exists
+	 */
+	abstract public function hasItemChild($itemName, $childName);
+	/**
+	 * Returns the children of the specified item.
+	 * @param mixed $itemName the parent item name. This can be either a string or an array.
+	 * The latter represents a list of item names.
+	 * @return Item[] all child items of the parent
+	 */
+	abstract public function getItemChildren($itemName);
+
+	/**
+	 * Assigns an authorization item to a user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @param string $bizRule the business rule to be executed when [[checkAccess()]] is called
+	 * for this particular authorization item.
+	 * @param mixed $data additional data associated with this assignment
+	 * @return Assignment the authorization assignment information.
+	 * @throws \yii\base\Exception if the item does not exist or if the item has already been assigned to the user
+	 */
+	abstract public function assign($userId, $itemName, $bizRule = null, $data = null);
+	/**
+	 * Revokes an authorization assignment from a user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @return boolean whether removal is successful
+	 */
+	abstract public function revoke($userId, $itemName);
+	/**
+	 * Returns a value indicating whether the item has been assigned to the user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @return boolean whether the item has been assigned to the user.
+	 */
+	abstract public function isAssigned($userId, $itemName);
+	/**
+	 * Returns the item assignment information.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @return Assignment the item assignment information. Null is returned if
+	 * the item is not assigned to the user.
+	 */
+	abstract public function getAssignment($userId, $itemName);
+	/**
+	 * Returns the item assignments for the specified user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @return Item[] the item assignment information for the user. An empty array will be
+	 * returned if there is no item assigned to the user.
+	 */
+	abstract public function getAssignments($userId);
+	/**
+	 * Saves the changes to an authorization assignment.
+	 * @param Assignment $assignment the assignment that has been changed.
+	 */
+	abstract public function saveAssignment($assignment);
+	/**
+	 * Removes all authorization data.
+	 */
+	abstract public function clearAll();
+	/**
+	 * Removes all authorization assignments.
+	 */
+	abstract public function clearAssignments();
+	/**
+	 * Saves authorization data into persistent storage.
+	 * If any change is made to the authorization data, please make
+	 * sure you call this method to save the changed data into persistent storage.
+	 */
+	abstract public function save();
+}
diff --git a/yii/rbac/PhpManager.php b/yii/rbac/PhpManager.php
new file mode 100644
index 0000000..8a4dbec
--- /dev/null
+++ b/yii/rbac/PhpManager.php
@@ -0,0 +1,516 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\rbac;
+
+use Yii;
+use yii\base\Exception;
+use yii\base\InvalidCallException;
+use yii\base\InvalidParamException;
+
+/**
+ * PhpManager represents an authorization manager that stores authorization
+ * information in terms of a PHP script file.
+ *
+ * The authorization data will be saved to and loaded from a file
+ * specified by [[authFile]], which defaults to 'protected/data/rbac.php'.
+ *
+ * PhpManager is mainly suitable for authorization data that is not too big
+ * (for example, the authorization data for a personal blog system).
+ * Use [[DbManager]] for more complex authorization data.
+ *
+ * @property array $authItems The authorization items of the specific type.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @since 2.0
+ */
+class PhpManager extends Manager
+{
+	/**
+	 * @var string the path of the PHP script that contains the authorization data.
+	 * If not set, it will be using 'protected/data/rbac.php' as the data file.
+	 * Make sure this file is writable by the Web server process if the authorization
+	 * needs to be changed.
+	 * @see loadFromFile
+	 * @see saveToFile
+	 */
+	public $authFile;
+
+	private $_items = array(); // itemName => item
+	private $_children = array(); // itemName, childName => child
+	private $_assignments = array(); // userId, itemName => assignment
+
+	/**
+	 * Initializes the application component.
+	 * This method overrides parent implementation by loading the authorization data
+	 * from PHP script.
+	 */
+	public function init()
+	{
+		parent::init();
+		if ($this->authFile === null) {
+			$this->authFile = Yii::getAlias('@app/data/rbac') . '.php';
+		}
+		$this->load();
+	}
+
+	/**
+	 * Performs access check for the specified user.
+	 * @param mixed $userId the user ID. This can be either an integer or a string representing
+	 * @param string $itemName the name of the operation that need access check
+	 * the unique identifier of a user. See [[User::id]].
+	 * @param array $params name-value pairs that would be passed to biz rules associated
+	 * with the tasks and roles assigned to the user. A param with name 'userId' is added to
+	 * this array, which holds the value of `$userId`.
+	 * @return boolean whether the operations can be performed by the user.
+	 */
+	public function checkAccess($userId, $itemName, $params = array())
+	{
+		if (!isset($this->_items[$itemName])) {
+			return false;
+		}
+		/** @var $item Item */
+		$item = $this->_items[$itemName];
+		Yii::trace('Checking permission: ' . $item->getName(), __METHOD__);
+		if (!isset($params['userId'])) {
+			$params['userId'] = $userId;
+		}
+		if ($this->executeBizRule($item->getBizRule(), $params, $item->getData())) {
+			if (in_array($itemName, $this->defaultRoles)) {
+				return true;
+			}
+			if (isset($this->_assignments[$userId][$itemName])) {
+				/** @var $assignment Assignment */
+				$assignment = $this->_assignments[$userId][$itemName];
+				if ($this->executeBizRule($assignment->getBizRule(), $params, $assignment->getData())) {
+					return true;
+				}
+			}
+			foreach ($this->_children as $parentName => $children) {
+				if (isset($children[$itemName]) && $this->checkAccess($userId, $parentName, $params)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Adds an item as a child of another item.
+	 * @param string $itemName the parent item name
+	 * @param string $childName the child item name
+	 * @return boolean whether the item is added successfully
+	 * @throws Exception if either parent or child doesn't exist.
+	 * @throws InvalidCallException if item already has a child with $itemName or if a loop has been detected.
+	 */
+	public function addItemChild($itemName, $childName)
+	{
+		if (!isset($this->_items[$childName], $this->_items[$itemName])) {
+			throw new Exception("Either '$itemName' or '$childName' does not exist.");
+		}
+		/** @var $child Item */
+		$child = $this->_items[$childName];
+		/** @var $item Item */
+		$item = $this->_items[$itemName];
+		$this->checkItemChildType($item->getType(), $child->getType());
+		if ($this->detectLoop($itemName, $childName)) {
+			throw new InvalidCallException("Cannot add '$childName' as a child of '$itemName'. A loop has been detected.");
+		}
+		if (isset($this->_children[$itemName][$childName])) {
+			throw new InvalidCallException("The item '$itemName' already has a child '$childName'.");
+		}
+		$this->_children[$itemName][$childName] = $this->_items[$childName];
+		return true;
+	}
+
+	/**
+	 * Removes a child from its parent.
+	 * Note, the child item is not deleted. Only the parent-child relationship is removed.
+	 * @param string $itemName the parent item name
+	 * @param string $childName the child item name
+	 * @return boolean whether the removal is successful
+	 */
+	public function removeItemChild($itemName, $childName)
+	{
+		if (isset($this->_children[$itemName][$childName])) {
+			unset($this->_children[$itemName][$childName]);
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * Returns a value indicating whether a child exists within a parent.
+	 * @param string $itemName the parent item name
+	 * @param string $childName the child item name
+	 * @return boolean whether the child exists
+	 */
+	public function hasItemChild($itemName, $childName)
+	{
+		return isset($this->_children[$itemName][$childName]);
+	}
+
+	/**
+	 * Returns the children of the specified item.
+	 * @param mixed $names the parent item name. This can be either a string or an array.
+	 * The latter represents a list of item names.
+	 * @return Item[] all child items of the parent
+	 */
+	public function getItemChildren($names)
+	{
+		if (is_string($names)) {
+			return isset($this->_children[$names]) ? $this->_children[$names] : array();
+		}
+
+		$children = array();
+		foreach ($names as $name) {
+			if (isset($this->_children[$name])) {
+				$children = array_merge($children, $this->_children[$name]);
+			}
+		}
+		return $children;
+	}
+
+	/**
+	 * Assigns an authorization item to a user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @param string $bizRule the business rule to be executed when [[checkAccess()]] is called
+	 * for this particular authorization item.
+	 * @param mixed $data additional data associated with this assignment
+	 * @return Assignment the authorization assignment information.
+	 * @throws InvalidParamException if the item does not exist or if the item has already been assigned to the user
+	 */
+	public function assign($userId, $itemName, $bizRule = null, $data = null)
+	{
+		if (!isset($this->_items[$itemName])) {
+			throw new InvalidParamException("Unknown authorization item '$itemName'.");
+		} elseif (isset($this->_assignments[$userId][$itemName])) {
+			throw new InvalidParamException("Authorization item '$itemName' has already been assigned to user '$userId'.");
+		} else {
+			return $this->_assignments[$userId][$itemName] = new Assignment($this, $userId, $itemName, $bizRule, $data);
+		}
+	}
+
+	/**
+	 * Revokes an authorization assignment from a user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @return boolean whether removal is successful
+	 */
+	public function revoke($userId, $itemName)
+	{
+		if (isset($this->_assignments[$userId][$itemName])) {
+			unset($this->_assignments[$userId][$itemName]);
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * Returns a value indicating whether the item has been assigned to the user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @return boolean whether the item has been assigned to the user.
+	 */
+	public function isAssigned($userId, $itemName)
+	{
+		return isset($this->_assignments[$userId][$itemName]);
+	}
+
+	/**
+	 * Returns the item assignment information.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @param string $itemName the item name
+	 * @return Assignment the item assignment information. Null is returned if
+	 * the item is not assigned to the user.
+	 */
+	public function getAssignment($userId, $itemName)
+	{
+		return isset($this->_assignments[$userId][$itemName]) ? $this->_assignments[$userId][$itemName] : null;
+	}
+
+	/**
+	 * Returns the item assignments for the specified user.
+	 * @param mixed $userId the user ID (see [[User::id]])
+	 * @return Assignment[] the item assignment information for the user. An empty array will be
+	 * returned if there is no item assigned to the user.
+	 */
+	public function getAssignments($userId)
+	{
+		return isset($this->_assignments[$userId]) ? $this->_assignments[$userId] : array();
+	}
+
+	/**
+	 * Returns the authorization items of the specific type and user.
+	 * @param mixed $userId the user ID. Defaults to null, meaning returning all items even if
+	 * they are not assigned to a user.
+	 * @param integer $type the item type (0: operation, 1: task, 2: role). Defaults to null,
+	 * meaning returning all items regardless of their type.
+	 * @return Item[] the authorization items of the specific type.
+	 */
+	public function getItems($userId = null, $type = null)
+	{
+		if ($userId === null && $type === null) {
+			return $this->_items;
+		}
+		$items = array();
+		if ($userId === null) {
+			foreach ($this->_items as $name => $item) {
+				/** @var $item Item */
+				if ($item->getType() == $type) {
+					$items[$name] = $item;
+				}
+			}
+		} elseif (isset($this->_assignments[$userId])) {
+			foreach ($this->_assignments[$userId] as $assignment) {
+				/** @var $assignment Assignment */
+				$name = $assignment->getItemName();
+				if (isset($this->_items[$name]) && ($type === null || $this->_items[$name]->getType() == $type)) {
+					$items[$name] = $this->_items[$name];
+				}
+			}
+		}
+		return $items;
+	}
+
+	/**
+	 * Creates an authorization item.
+	 * An authorization item represents an action permission (e.g. creating a post).
+	 * It has three types: operation, task and role.
+	 * Authorization items form a hierarchy. Higher level items inheirt permissions representing
+	 * by lower level items.
+	 * @param string $name the item name. This must be a unique identifier.
+	 * @param integer $type the item type (0: operation, 1: task, 2: role).
+	 * @param string $description description of the item
+	 * @param string $bizRule business rule associated with the item. This is a piece of
+	 * PHP code that will be executed when [[checkAccess()]] is called for the item.
+	 * @param mixed $data additional data associated with the item.
+	 * @return Item the authorization item
+	 * @throws Exception if an item with the same name already exists
+	 */
+	public function createItem($name, $type, $description = '', $bizRule = null, $data = null)
+	{
+		if (isset($this->_items[$name])) {
+			throw new Exception('Unable to add an item whose name is the same as an existing item.');
+		}
+		return $this->_items[$name] = new Item($this, $name, $type, $description, $bizRule, $data);
+	}
+
+	/**
+	 * Removes the specified authorization item.
+	 * @param string $name the name of the item to be removed
+	 * @return boolean whether the item exists in the storage and has been removed
+	 */
+	public function removeItem($name)
+	{
+		if (isset($this->_items[$name])) {
+			foreach ($this->_children as &$children) {
+				unset($children[$name]);
+			}
+			foreach ($this->_assignments as &$assignments) {
+				unset($assignments[$name]);
+			}
+			unset($this->_items[$name]);
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * Returns the authorization item with the specified name.
+	 * @param string $name the name of the item
+	 * @return Item the authorization item. Null if the item cannot be found.
+	 */
+	public function getItem($name)
+	{
+		return isset($this->_items[$name]) ? $this->_items[$name] : null;
+	}
+
+	/**
+	 * Saves an authorization item to persistent storage.
+	 * @param Item $item the item to be saved.
+	 * @param string $oldName the old item name. If null, it means the item name is not changed.
+	 * @throws InvalidParamException if an item with the same name already taken
+	 */
+	public function saveItem($item, $oldName = null)
+	{
+		if ($oldName !== null && ($newName = $item->getName()) !== $oldName) // name changed
+		{
+			if (isset($this->_items[$newName])) {
+				throw new InvalidParamException("Unable to change the item name. The name '$newName' is already used by another item.");
+			}
+			if (isset($this->_items[$oldName]) && $this->_items[$oldName] === $item) {
+				unset($this->_items[$oldName]);
+				$this->_items[$newName] = $item;
+				if (isset($this->_children[$oldName])) {
+					$this->_children[$newName] = $this->_children[$oldName];
+					unset($this->_children[$oldName]);
+				}
+				foreach ($this->_children as &$children) {
+					if (isset($children[$oldName])) {
+						$children[$newName] = $children[$oldName];
+						unset($children[$oldName]);
+					}
+				}
+				foreach ($this->_assignments as &$assignments) {
+					if (isset($assignments[$oldName])) {
+						$assignments[$newName] = $assignments[$oldName];
+						unset($assignments[$oldName]);
+					}
+				}
+			}
+		}
+	}
+
+	/**
+	 * Saves the changes to an authorization assignment.
+	 * @param Assignment $assignment the assignment that has been changed.
+	 */
+	public function saveAssignment($assignment)
+	{
+	}
+
+	/**
+	 * Saves authorization data into persistent storage.
+	 * If any change is made to the authorization data, please make
+	 * sure you call this method to save the changed data into persistent storage.
+	 */
+	public function save()
+	{
+		$items = array();
+		foreach ($this->_items as $name => $item) {
+			/** @var $item Item */
+			$items[$name] = array(
+				'type' => $item->getType(),
+				'description' => $item->getDescription(),
+				'bizRule' => $item->getBizRule(),
+				'data' => $item->getData(),
+			);
+			if (isset($this->_children[$name])) {
+				foreach ($this->_children[$name] as $child) {
+					/** @var $child Item */
+					$items[$name]['children'][] = $child->getName();
+				}
+			}
+		}
+
+		foreach ($this->_assignments as $userId => $assignments) {
+			foreach ($assignments as $name => $assignment) {
+				/** @var $assignment Assignment */
+				if (isset($items[$name])) {
+					$items[$name]['assignments'][$userId] = array(
+						'bizRule' => $assignment->getBizRule(),
+						'data' => $assignment->getData(),
+					);
+				}
+			}
+		}
+
+		$this->saveToFile($items, $this->authFile);
+	}
+
+	/**
+	 * Loads authorization data.
+	 */
+	public function load()
+	{
+		$this->clearAll();
+
+		$items = $this->loadFromFile($this->authFile);
+
+		foreach ($items as $name => $item) {
+			$this->_items[$name] = new Item($this, $name, $item['type'], $item['description'], $item['bizRule'], $item['data']);
+		}
+
+		foreach ($items as $name => $item) {
+			if (isset($item['children'])) {
+				foreach ($item['children'] as $childName) {
+					if (isset($this->_items[$childName])) {
+						$this->_children[$name][$childName] = $this->_items[$childName];
+					}
+				}
+			}
+			if (isset($item['assignments'])) {
+				foreach ($item['assignments'] as $userId => $assignment) {
+					$this->_assignments[$userId][$name] = new Assignment($this, $name, $userId, $assignment['bizRule'], $assignment['data']);
+				}
+			}
+		}
+	}
+
+	/**
+	 * Removes all authorization data.
+	 */
+	public function clearAll()
+	{
+		$this->clearAssignments();
+		$this->_children = array();
+		$this->_items = array();
+	}
+
+	/**
+	 * Removes all authorization assignments.
+	 */
+	public function clearAssignments()
+	{
+		$this->_assignments = array();
+	}
+
+	/**
+	 * Checks whether there is a loop in the authorization item hierarchy.
+	 * @param string $itemName parent item name
+	 * @param string $childName the name of the child item that is to be added to the hierarchy
+	 * @return boolean whether a loop exists
+	 */
+	protected function detectLoop($itemName, $childName)
+	{
+		if ($childName === $itemName) {
+			return true;
+		}
+		if (!isset($this->_children[$childName], $this->_items[$itemName])) {
+			return false;
+		}
+		foreach ($this->_children[$childName] as $child) {
+			/** @var $child Item */
+			if ($this->detectLoop($itemName, $child->getName())) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Loads the authorization data from a PHP script file.
+	 * @param string $file the file path.
+	 * @return array the authorization data
+	 * @see saveToFile
+	 */
+	protected function loadFromFile($file)
+	{
+		if (is_file($file)) {
+			return require($file);
+		} else {
+			return array();
+		}
+	}
+
+	/**
+	 * Saves the authorization data to a PHP script file.
+	 * @param array $data the authorization data
+	 * @param string $file the file path.
+	 * @see loadFromFile
+	 */
+	protected function saveToFile($data, $file)
+	{
+		file_put_contents($file, "<?php\nreturn " . var_export($data, true) . ";\n", LOCK_EX);
+	}
+}
diff --git a/yii/rbac/schema-mssql.sql b/yii/rbac/schema-mssql.sql
new file mode 100644
index 0000000..a1170b1
--- /dev/null
+++ b/yii/rbac/schema-mssql.sql
@@ -0,0 +1,43 @@
+/**
+ * Database schema required by \yii\rbac\DbManager.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @link http://www.yiiframework.com/
+ * @copyright 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ * @since 2.0
+ */
+
+drop table if exists [tbl_auth_assignment];
+drop table if exists [tbl_auth_item_child];
+drop table if exists [tbl_auth_item];
+
+create table [tbl_auth_item]
+(
+   [name]                 varchar(64) not null,
+   [type]                 integer not null,
+   [description]          text,
+   [bizrule]              text,
+   [data]                 text,
+   primary key ([name])
+);
+
+create table [tbl_auth_item_child]
+(
+   [parent]               varchar(64) not null,
+   [child]                varchar(64) not null,
+   primary key ([parent],[child]),
+   foreign key ([parent]) references [tbl_auth_item] ([name]) on delete cascade on update cascade,
+   foreign key ([child]) references [tbl_auth_item] ([name]) on delete cascade on update cascade
+);
+
+create table [tbl_auth_assignment]
+(
+   [item_name]            varchar(64) not null,
+   [user_id]              varchar(64) not null,
+   [bizrule]              text,
+   [data]                 text,
+   primary key ([item_name],[user_id]),
+   foreign key ([item_name]) references [tbl_auth_item] ([name]) on delete cascade on update cascade
+);
diff --git a/yii/rbac/schema-mysql.sql b/yii/rbac/schema-mysql.sql
new file mode 100644
index 0000000..aa8015b
--- /dev/null
+++ b/yii/rbac/schema-mysql.sql
@@ -0,0 +1,43 @@
+/**
+ * Database schema required by \yii\rbac\DbManager.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @link http://www.yiiframework.com/
+ * @copyright 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ * @since 2.0
+ */
+
+drop table if exists `tbl_auth_assignment`;
+drop table if exists `tbl_auth_item_child`;
+drop table if exists `tbl_auth_item`;
+
+create table `tbl_auth_item`
+(
+   `name`                 varchar(64) not null,
+   `type`                 integer not null,
+   `description`          text,
+   `bizrule`              text,
+   `data`                 text,
+   primary key (`name`)
+) engine InnoDB;
+
+create table `tbl_auth_item_child`
+(
+   `parent`               varchar(64) not null,
+   `child`                varchar(64) not null,
+   primary key (`parent`,`child`),
+   foreign key (`parent`) references `tbl_auth_item` (`name`) on delete cascade on update cascade,
+   foreign key (`child`) references `tbl_auth_item` (`name`) on delete cascade on update cascade
+) engine InnoDB;
+
+create table `tbl_auth_assignment`
+(
+   `item_name`            varchar(64) not null,
+   `user_id`              varchar(64) not null,
+   `bizrule`              text,
+   `data`                 text,
+   primary key (`item_name`,`user_id`),
+   foreign key (`item_name`) references `tbl_auth_item` (`name`) on delete cascade on update cascade
+) engine InnoDB;
diff --git a/yii/rbac/schema-oci.sql b/yii/rbac/schema-oci.sql
new file mode 100644
index 0000000..16b7964
--- /dev/null
+++ b/yii/rbac/schema-oci.sql
@@ -0,0 +1,43 @@
+/**
+ * Database schema required by \yii\rbac\DbManager.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @link http://www.yiiframework.com/
+ * @copyright 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ * @since 2.0
+ */
+
+drop table if exists "tbl_auth_assignment";
+drop table if exists "tbl_auth_item_child";
+drop table if exists "tbl_auth_item";
+
+create table "tbl_auth_item"
+(
+   "name"                 varchar(64) not null,
+   "type"                 integer not null,
+   "description"          text,
+   "bizrule"              text,
+   "data"                 text,
+   primary key ("name")
+);
+
+create table "tbl_auth_item_child"
+(
+   "parent"               varchar(64) not null,
+   "child"                varchar(64) not null,
+   primary key ("parent","child"),
+   foreign key ("parent") references "tbl_auth_item" ("name") on delete cascade on update cascade,
+   foreign key ("child") references "tbl_auth_item" ("name") on delete cascade on update cascade
+);
+
+create table "tbl_auth_assignment"
+(
+   "item_name"            varchar(64) not null,
+   "user_id"              varchar(64) not null,
+   "bizrule"              text,
+   "data"                 text,
+   primary key ("item_name","user_id"),
+   foreign key ("item_name") references "tbl_auth_item" ("name") on delete cascade on update cascade
+);
diff --git a/yii/rbac/schema-pgsql.sql b/yii/rbac/schema-pgsql.sql
new file mode 100644
index 0000000..16b7964
--- /dev/null
+++ b/yii/rbac/schema-pgsql.sql
@@ -0,0 +1,43 @@
+/**
+ * Database schema required by \yii\rbac\DbManager.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @link http://www.yiiframework.com/
+ * @copyright 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ * @since 2.0
+ */
+
+drop table if exists "tbl_auth_assignment";
+drop table if exists "tbl_auth_item_child";
+drop table if exists "tbl_auth_item";
+
+create table "tbl_auth_item"
+(
+   "name"                 varchar(64) not null,
+   "type"                 integer not null,
+   "description"          text,
+   "bizrule"              text,
+   "data"                 text,
+   primary key ("name")
+);
+
+create table "tbl_auth_item_child"
+(
+   "parent"               varchar(64) not null,
+   "child"                varchar(64) not null,
+   primary key ("parent","child"),
+   foreign key ("parent") references "tbl_auth_item" ("name") on delete cascade on update cascade,
+   foreign key ("child") references "tbl_auth_item" ("name") on delete cascade on update cascade
+);
+
+create table "tbl_auth_assignment"
+(
+   "item_name"            varchar(64) not null,
+   "user_id"              varchar(64) not null,
+   "bizrule"              text,
+   "data"                 text,
+   primary key ("item_name","user_id"),
+   foreign key ("item_name") references "tbl_auth_item" ("name") on delete cascade on update cascade
+);
diff --git a/yii/rbac/schema-sqlite.sql b/yii/rbac/schema-sqlite.sql
new file mode 100644
index 0000000..668196e
--- /dev/null
+++ b/yii/rbac/schema-sqlite.sql
@@ -0,0 +1,43 @@
+/**
+ * Database schema required by \yii\rbac\DbManager.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Alexander Kochetov <creocoder@gmail.com>
+ * @link http://www.yiiframework.com/
+ * @copyright 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ * @since 2.0
+ */
+
+drop table if exists 'tbl_auth_assignment';
+drop table if exists 'tbl_auth_item_child';
+drop table if exists 'tbl_auth_item';
+
+create table 'tbl_auth_item'
+(
+   "name"                 varchar(64) not null,
+   "type"                 integer not null,
+   "description"          text,
+   "bizrule"              text,
+   "data"                 text,
+   primary key ("name")
+);
+
+create table 'tbl_auth_item_child'
+(
+   "parent"               varchar(64) not null,
+   "child"                varchar(64) not null,
+   primary key ("parent","child"),
+   foreign key ("parent") references 'tbl_auth_item' ("name") on delete cascade on update cascade,
+   foreign key ("child") references 'tbl_auth_item' ("name") on delete cascade on update cascade
+);
+
+create table 'tbl_auth_assignment'
+(
+   "item_name"            varchar(64) not null,
+   "user_id"              varchar(64) not null,
+   "bizrule"              text,
+   "data"                 text,
+   primary key ("item_name","user_id"),
+   foreign key ("item_name") references 'tbl_auth_item' ("name") on delete cascade on update cascade
+);
diff --git a/yii/web/User.php b/yii/web/User.php
index 88fc12d..7d8e300 100644
--- a/yii/web/User.php
+++ b/yii/web/User.php
@@ -40,11 +40,11 @@ class User extends Component
 	 */
 	public $enableAutoLogin = false;
 	/**
-	 * @var string|array the URL for login when [[loginRequired()]] is called. 
+	 * @var string|array the URL for login when [[loginRequired()]] is called.
 	 * If an array is given, [[UrlManager::createUrl()]] will be called to create the corresponding URL.
-	 * The first element of the array should be the route to the login action, and the rest of 
+	 * The first element of the array should be the route to the login action, and the rest of
 	 * the name-value pairs are GET parameters used to construct the login URL. For example,
-	 * 
+	 *
 	 * ~~~
 	 * array('site/login', 'ref' => 1)
 	 * ~~~
@@ -86,6 +86,8 @@ class User extends Component
 	 */
 	public $returnUrlVar = '__returnUrl';
 
+	private $_access = array();
+
 
 	/**
 	 * Initializes the application component.
@@ -449,19 +451,33 @@ class User extends Component
 	}
 
 	/**
-	 * Checks whether the user has access to the specified operation.
-	 * @param $operator
-	 * @param array $params
-	 * @return bool
-	 * @todo
+	 * Performs access check for this user.
+	 * @param string $operation the name of the operation that need access check.
+	 * @param array $params name-value pairs that would be passed to business rules associated
+	 * with the tasks and roles assigned to the user. A param with name 'userId' is added to
+	 * this array, which holds the value of [[id]] when [[DbAuthManager]] or
+	 * [[PhpAuthManager]] is used.
+	 * @param boolean $allowCaching whether to allow caching the result of access check.
+	 * When this parameter is true (default), if the access check of an operation was performed
+	 * before, its result will be directly returned when calling this method to check the same
+	 * operation. If this parameter is false, this method will always call
+	 * [[AuthManager::checkAccess()]] to obtain the up-to-date access result. Note that this
+	 * caching is effective only within the same request and only works when `$params = array()`.
+	 * @return boolean whether the operations can be performed by this user.
 	 */
-	public function checkAccess($operation, $params = array())
+	public function checkAccess($operation, $params = array(), $allowCaching = true)
 	{
 		$auth = Yii::$app->getAuthManager();
-		if ($auth !== null) {
-			return $auth->checkAccess($this->getId(), $operation, $params);
-		} else {
+		if ($auth === null) {
 			return false;
 		}
+		if ($allowCaching && empty($params) && isset($this->_access[$operation])) {
+			return $this->_access[$operation];
+		}
+		$access = $auth->checkAccess($this->getId(), $operation, $params);
+		if ($allowCaching && empty($params)) {
+			$this->_access[$operation] = $access;
+		}
+		return $access;
 	}
 }
diff --git a/yii/yiic.php b/yii/yiic.php
index 7cd0c40..3be0436 100644
--- a/yii/yiic.php
+++ b/yii/yiic.php
@@ -7,6 +7,10 @@
  * @license http://www.yiiframework.com/license/
  */
 
+if(!ini_get('date.timezone')) {
+	date_default_timezone_set('UTC');
+}
+
 defined('YII_DEBUG') or define('YII_DEBUG', true);
 
 // fcgi doesn't have STDIN defined by default