Support auto-activation of Nav.

apps/basic/views/layouts/main.php

 <?php
-use yii\bootstrap\NavBar;
 use yii\helpers\Html;
-use yii\widgets\Menu;
+use yii\bootstrap\Nav;
+use yii\bootstrap\NavBar;
 use yii\widgets\Breadcrumbs;
 
 /**
@@ -28,8 +28,8 @@ app\config\AppAsset::register($this);
 				'class' => 'navbar-inverse navbar-fixed-top',
 			),
 		));
-		echo Menu::widget(array(
-			'options' => array('class' => 'nav navbar-nav pull-right'),
+		echo Nav::widget(array(
+			'options' => array('class' => 'navbar-nav pull-right'),
 			'items' => array(
 				array('label' => 'Home', 'url' => array('/site/index')),
 				array('label' => 'About', 'url' => array('/site/about')),

framework/yii/bootstrap/Nav.php

@@ -7,6 +7,7 @@
 
 namespace yii\bootstrap;
 
+use Yii;
 use yii\base\InvalidConfigException;
 use yii\helpers\ArrayHelper;
 use yii\helpers\Html;
@@ -21,9 +22,8 @@ use yii\helpers\Html;
  *     'items' => array(
  *         array(
  *             'label' => 'Home',
- *             'url' => '/',
+ *             'url' => array('site/index'),
  *             'linkOptions' => array(...),
- *             'active' => true,
  *         ),
  *         array(
  *             'label' => 'Dropdown',
@@ -63,7 +63,7 @@ class Nav extends Widget
 	 * - linkOptions: array, optional, the HTML attributes of the item's link.
 	 * - options: array, optional, the HTML attributes of the item container (LI).
 	 * - active: boolean, optional, whether the item should be on active state or not.
-	 * - dropdown: array|string, optional, the configuration array for creating a [[Dropdown]] widget,
+	 * - items: array|string, optional, the configuration array for creating a [[Dropdown]] widget,
 	 *   or a string representing the dropdown menu. Note that Bootstrap does not support sub-dropdown menus.
 	 */
 	public $items = array();
@@ -71,6 +71,26 @@ class Nav extends Widget
 	 * @var boolean whether the nav items labels should be HTML-encoded.
 	 */
 	public $encodeLabels = true;
+	/**
+	 * @var boolean whether to automatically activate items according to whether their route setting
+	 * matches the currently requested route.
+	 * @see isItemActive
+	 */
+	public $activateItems = true;
+	/**
+	 * @var string the route used to determine if a menu item is active or not.
+	 * If not set, it will use the route of the current request.
+	 * @see params
+	 * @see isItemActive
+	 */
+	public $route;
+	/**
+	 * @var array the parameters used to determine if a menu item is active or not.
+	 * If not set, it will use `$_GET`.
+	 * @see route
+	 * @see isItemActive
+	 */
+	public $params;
 
 
 	/**
@@ -79,6 +99,12 @@ class Nav extends Widget
 	public function init()
 	{
 		parent::init();
+		if ($this->route === null && Yii::$app->controller !== null) {
+			$this->route = Yii::$app->controller->getRoute();
+		}
+		if ($this->params === null) {
+			$this->params = $_GET;
+		}
 		Html::addCssClass($this->options, 'nav');
 	}
 
@@ -124,7 +150,13 @@ class Nav extends Widget
 		$url = Html::url(ArrayHelper::getValue($item, 'url', '#'));
 		$linkOptions = ArrayHelper::getValue($item, 'linkOptions', array());
 
-		if (ArrayHelper::getValue($item, 'active')) {
+		if (isset($item['active'])) {
+			$active = ArrayHelper::remove($item, 'active', false);
+		} else {
+			$active = $this->isItemActive($item);
+		}
+
+		if ($active) {
 			Html::addCssClass($options, 'active');
 		}
 
@@ -144,4 +176,31 @@ class Nav extends Widget
 
 		return Html::tag('li', Html::a($label, $url, $linkOptions) . $items, $options);
 	}
+
+
+	/**
+	 * Checks whether a menu item is active.
+	 * This is done by checking if [[route]] and [[params]] match that specified in the `url` option of the menu item.
+	 * When the `url` option of a menu item is specified in terms of an array, its first element is treated
+	 * as the route for the item and the rest of the elements are the associated parameters.
+	 * Only when its route and parameters match [[route]] and [[params]], respectively, will a menu item
+	 * be considered active.
+	 * @param array $item the menu item to be checked
+	 * @return boolean whether the menu item is active
+	 */
+	protected function isItemActive($item)
+	{
+		if (isset($item['url']) && is_array($item['url']) && trim($item['url'][0], '/') === $this->route) {
+			unset($item['url']['#']);
+			if (count($item['url']) > 1) {
+				foreach (array_splice($item['url'], 1) as $name => $value) {
+					if (!isset($this->params[$name]) || $this->params[$name] != $value) {
+						return false;
+					}
+				}
+			}
+			return true;
+		}
+		return false;
+	}
 }