# Class yii\bootstrap\Nav

Inheritance | yii\bootstrap\Nav » yii\bootstrap\Widget » yii\base\Widget » yii\base\Component » yii\base\BaseObject
Implements | yii\base\Configurable, yii\base\ViewContextInterface
Uses Traits | yii\bootstrap\BootstrapWidgetTrait
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2-bootstrap/blob/master/Nav.php

Nav renders a nav HTML component.

For example:

    echo Nav::widget([
        'items' => [
            [
                'label' => 'Home',
                'url' => ['site/index'],
                'linkOptions' => [...],
            ],
            [
                'label' => 'Dropdown',
                'items' => [
                     ['label' => 'Level 1 - Dropdown A', 'url' => '#'],
                     '<li class="divider"></li>',
                     '<li class="dropdown-header">Dropdown Header</li>',
                     ['label' => 'Level 1 - Dropdown B', 'url' => '#'],
                ],
            ],
            [
                'label' => 'Login',
                'url' => ['site/login'],
                'visible' => Yii::$app->user->isGuest
            ],
        ],
        'options' => ['class' =>'nav-pills'], // set this to nav-tab to get tab-styled navigation
    ]);

Note: Multilevel dropdowns beyond Level 1 are not supported in Bootstrap 3.

See also:

- https://getbootstrap.com/docs/3.3/components/#dropdowns
- https://getbootstrap.com/docs/3.3/components/#nav

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$activateItems | boolean | Whether to automatically activate items according to whether their route setting matches the currently requested route. | yii\bootstrap\Nav
$activateParents | boolean | Whether to activate parent menu items when one of the corresponding child menu items is active. | yii\bootstrap\Nav
$autoIdPrefix | string | The prefix to the automatically generated widget IDs. | yii\base\Widget
$behaviors | yii\base\Behavior[] | List of behaviors attached to this component. This property is read-only. | yii\base\Component
$clientEvents | array | The event handlers for the underlying Bootstrap JS plugin. | yii\bootstrap\BootstrapWidgetTrait
$clientOptions | array | The options for the underlying Bootstrap JS plugin. | yii\bootstrap\BootstrapWidgetTrait
$counter | integer | A counter used to generate $id for widgets. | yii\base\Widget
$dropDownCaret | string | This property allows you to customize the HTML which is used to generate the drop down caret symbol, which is displayed next to the button text to indicate the drop down functionality. | yii\bootstrap\Nav
$dropdownClass | string | Name of a class to use for rendering dropdowns within this widget. | yii\bootstrap\Nav
$encodeLabels | boolean | Whether the nav items labels should be HTML-encoded. | yii\bootstrap\Nav
$id | string|null | ID of the widget. Note that the type of this property differs in getter and setter. See getId() and setId() for details. | yii\base\Widget
$items | array | List of items in the nav widget. | yii\bootstrap\Nav
$options | array | The HTML attributes for the widget container tag. | yii\bootstrap\Widget
$params | array | The parameters used to determine if a menu item is active or not. | yii\bootstrap\Nav
$route | string | The route used to determine if a menu item is active or not. | yii\bootstrap\Nav
$stack | yii\base\Widget[] | The widgets that are currently being rendered (not ended). | yii\base\Widget
$view | yii\web\View | The view object that can be used to render views or view files. Note that the type of this property differs in getter and setter. See getView() and setView() for details. | yii\base\Widget
$viewPath | string | The directory containing the view files for this widget. This property is read-only. | yii\base\Widget

## Public Methods

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Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\Component
__clone() | This method is called after the object is created by cloning an existing one. | yii\base\Component
__construct() | Constructor. | yii\base\BaseObject
__get() | Returns the value of a component property. | yii\base\Component
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\Component
__set() | Sets the value of a component property. | yii\base\Component
__unset() | Sets a component property to be null. | yii\base\Component
afterRun() | This method is invoked right after a widget is executed. | yii\base\Widget
attachBehavior() | Attaches a behavior to this component. | yii\base\Component
attachBehaviors() | Attaches a list of behaviors to the component. | yii\base\Component
beforeRun() | This method is invoked right before the widget is executed. | yii\base\Widget
begin() | Begins a widget. | yii\base\Widget
behaviors() | Returns a list of behaviors that this component should behave as. | yii\base\Component
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\Component
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\Component
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
detachBehavior() | Detaches a behavior from the component. | yii\base\Component
detachBehaviors() | Detaches all behaviors from the component. | yii\base\Component
end() | Ends a widget. | yii\base\Widget
ensureBehaviors() | Makes sure that the behaviors declared in behaviors() are attached to this component. | yii\base\Component
getBehavior() | Returns the named behavior object. | yii\base\Component
getBehaviors() | Returns all behaviors attached to this component. | yii\base\Component
getId() | Returns the ID of the widget. | yii\base\Widget
getView() |  | yii\bootstrap\BootstrapWidgetTrait
getViewPath() | Returns the directory containing the view files for this widget. | yii\base\Widget
hasEventHandlers() | Returns a value indicating whether there is any handler attached to the named event. | yii\base\Component
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\Component
hasProperty() | Returns a value indicating whether a property is defined for this component. | yii\base\Component
init() | Initializes the widget. | yii\bootstrap\Nav
off() | Detaches an existing event handler from this component. | yii\base\Component
on() | Attaches an event handler to an event. | yii\base\Component
render() | Renders a view. | yii\base\Widget
renderFile() | Renders a view file. | yii\base\Widget
renderItem() | Renders a widget's item. | yii\bootstrap\Nav
renderItems() | Renders widget items. | yii\bootstrap\Nav
run() | Renders the widget. | yii\bootstrap\Nav
setId() | Sets the ID of the widget. | yii\base\Widget
setView() | Sets the view object to be used by this widget. | yii\base\Widget
trigger() | Triggers an event. | yii\base\Component
widget() | Creates a widget instance and runs it. | yii\base\Widget

## Protected Methods

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Method | Description | Defined By
--- | --- | ---
isChildActive() | Check to see if a child item is active optionally activating the parent. | yii\bootstrap\Nav
isItemActive() | Checks whether a menu item is active. | yii\bootstrap\Nav
registerClientEvents() | Registers JS event handlers that are listed in $clientEvents. | yii\bootstrap\BootstrapWidgetTrait
registerPlugin() | Registers a specific Bootstrap plugin and the related events | yii\bootstrap\BootstrapWidgetTrait
renderDropdown() | Renders the given items as a dropdown. | yii\bootstrap\Nav

## Events

Hide inherited events

Event | Type | Description | Defined By
--- | --- | --- | ---
EVENT_AFTER_RUN | yii\base\WidgetEvent | An event raised right after executing a widget. (available since version 2.0.11) | yii\base\Widget
EVENT_BEFORE_RUN | yii\base\WidgetEvent | An event raised right before executing a widget. (available since version 2.0.11) | yii\base\Widget
EVENT_INIT | yii\base\Event | An event that is triggered when the widget is initialized via init(). (available since version 2.0.11) | yii\base\Widget

## Property Details

$activateItems public property

Whether to automatically activate items according to whether their route setting matches the currently requested route.

See also isItemActive().

public boolean $activateItems = true
$activateParents public property

Whether to activate parent menu items when one of the corresponding child menu items is active.

public boolean $activateParents = false
$dropDownCaret public property

This property allows you to customize the HTML which is used to generate the drop down caret symbol, which is displayed next to the button text to indicate the drop down functionality. Defaults to `null` which means `<span class="caret"></span>` will be used. To disable the caret, set this property to be an empty string.

public string $dropDownCaret = null
$dropdownClass public property (available since version 2.0.7)

Name of a class to use for rendering dropdowns within this widget. Defaults to yii\bootstrap\Dropdown.

public string $dropdownClass = 'yii\bootstrap\Dropdown'
$encodeLabels public property

Whether the nav items labels should be HTML-encoded.

public boolean $encodeLabels = true
$items public property

List of items in the nav widget. Each array element represents a single menu item which can be either a string or an array with the following structure:

- label: string, required, the nav item label.
- url: optional, the item's URL. Defaults to "#".
- visible: bool, optional, whether this menu item is visible. Defaults to true.
- linkOptions: array, optional, the HTML attributes of the item's link.
- options: array, optional, the HTML attributes of the item container (LI).
- active: bool, optional, whether the item should be on active state or not.
- dropDownOptions: array, optional, the HTML options that will passed to the yii\bootstrap\Dropdown widget.
- items: array|string, optional, the configuration array for creating a yii\bootstrap\Dropdown widget, or a string representing the dropdown menu. Note that Bootstrap does not support sub-dropdown menus.
- encode: bool, optional, whether the label will be HTML-encoded. If set, supersedes the $encodeLabels option for only this item.

If a menu item is a string, it will be rendered directly without HTML encoding.

public array $items = []
$params public property

The parameters used to determine if a menu item is active or not. If not set, it will use `$_GET`.

See also:

- $route
- isItemActive()

public array $params = null
$route public property

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 also:

- $params
- isItemActive()

public string $route = null

## Method Details

init() public method

Initializes the widget.

public void init ( )

isChildActive() protected method

Check to see if a child item is active optionally activating the parent.

protected array isChildActive ( $items, &$active )
$items | array | @see items
$active | boolean | Should the parent be active too
return | array | @see items

isItemActive() protected method

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.

protected boolean isItemActive ( $item )
$item | array | The menu item to be checked
return | boolean | Whether the menu item is active

renderDropdown() protected method (available since version 2.0.1)

Renders the given items as a dropdown.

This method is called to create sub-menus.

protected string renderDropdown ( $items, $parentItem )
$items | array | The given items. Please refer to yii\bootstrap\Dropdown::$items for the array structure.
$parentItem | array | The parent item information. Please refer to $items for the structure of this array.
return | string | The rendering result.

renderItem() public method

Renders a widget's item.

public string renderItem ( $item )
$item | string|array | The item to render.
return | string | The rendering result.
throws | yii\base\InvalidConfigException |

renderItems() public method

Renders widget items.

public void renderItems ( )

run() public method

Renders the widget.

public void run ( )