# Class yii\base\Widget

Inheritance | yii\base\Widget » yii\base\Component » yii\base\BaseObject
Implements | yii\base\Configurable, yii\base\ViewContextInterface
Subclasses | yii\apidoc\templates\bootstrap\SideNavWidget, yii\authclient\widgets\AuthChoice, yii\authclient\widgets\AuthChoiceItem, yii\authclient\widgets\GooglePlusButton, yii\bootstrap\ActiveForm, yii\bootstrap\Alert, yii\bootstrap\Button, yii\bootstrap\ButtonDropdown, yii\bootstrap\ButtonGroup, yii\bootstrap\Carousel, yii\bootstrap\Collapse, yii\bootstrap\Dropdown, yii\bootstrap\InputWidget, yii\bootstrap\Modal, yii\bootstrap\Nav, yii\bootstrap\NavBar, yii\bootstrap\Progress, yii\bootstrap\Tabs, yii\bootstrap\ToggleButtonGroup, yii\bootstrap\Widget, yii\captcha\Captcha, yii\console\widgets\Table, yii\debug\widgets\NavigationButton, yii\grid\GridView, yii\jui\Accordion, yii\jui\AutoComplete, yii\jui\DatePicker, yii\jui\Dialog, yii\jui\Draggable, yii\jui\Droppable, yii\jui\InputWidget, yii\jui\Menu, yii\jui\ProgressBar, yii\jui\Resizable, yii\jui\Selectable, yii\jui\Slider, yii\jui\SliderInput, yii\jui\Sortable, yii\jui\Spinner, yii\jui\Tabs, yii\jui\Widget, yii\widgets\ActiveForm, yii\widgets\BaseListView, yii\widgets\Block, yii\widgets\Breadcrumbs, yii\widgets\ContentDecorator, yii\widgets\DetailView, yii\widgets\FragmentCache, yii\widgets\InputWidget, yii\widgets\LinkPager, yii\widgets\LinkSorter, yii\widgets\ListView, yii\widgets\MaskedInput, yii\widgets\Menu, yii\widgets\Pjax, yii\widgets\Spaceless
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/base/Widget.php

Widget is the base class for widgets.

For more details and usage information on Widget, see the guide article on widgets.

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$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
$counter | integer | A counter used to generate $id for widgets. | yii\base\Widget
$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
$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

Hide inherited methods

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() | Returns the view object that can be used to render views or view files. | yii\base\Widget
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 object. | yii\base\Widget
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
run() | Executes the widget. | yii\base\Widget
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

## 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

$autoIdPrefix public static property

The prefix to the automatically generated widget IDs.

See also getId().

public static string $autoIdPrefix = 'w'
$counter public static property

A counter used to generate $id for widgets.

public static integer $counter = 0
$id public property

ID of the widget. Note that the type of this property differs in getter and setter. See getId() and setId() for details.

public string|null $id = null
$stack public static property

The widgets that are currently being rendered (not ended). This property is maintained by begin() and end() methods.

public static yii\base\Widget[] $stack = []
$view public property

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.

public yii\web\View $view = null
$viewPath public property

The directory containing the view files for this widget. This property is read-only.

public string $viewPath = null

## Method Details

afterRun() public method (available since version 2.0.11)

This method is invoked right after a widget is executed.

The method will trigger the EVENT_AFTER_RUN event. The return value of the method will be used as the widget return value.

If you override this method, your code should look like the following:

    public function afterRun($result)
    {
        $result = parent::afterRun($result);
        // your custom code here
        return $result;
    }

public mixed afterRun ( $result )
$result | mixed | The widget return result.
return | mixed | The processed widget result.

beforeRun() public method (available since version 2.0.11)

This method is invoked right before the widget is executed.

The method will trigger the EVENT_BEFORE_RUN event. The return value of the method will determine whether the widget should continue to run.

When overriding this method, make sure you call the parent implementation like the following:

    public function beforeRun()
    {
        if (!parent::beforeRun()) {
            return false;
        }

        // your custom code here

        return true; // or false to not run the widget
    }

public boolean beforeRun ( )
return | boolean | Whether the widget should continue to be executed.

begin() public static method

Begins a widget.

This method creates an instance of the calling class. It will apply the configuration to the created instance. A matching end() call should be called later. As some widgets may use output buffering, the end() call should be made in the same view to avoid breaking the nesting of output buffers.

See also end().

public static static begin ( $config = [] )
$config | array | Name-value pairs that will be used to initialize the object properties
return | static | The newly created widget instance

end() public static method

Ends a widget.

Note that the rendering result of the widget is directly echoed out.

See also begin().

public static static end ( )
return | static | The widget instance that is ended.
throws | yii\base\InvalidCallException | if begin() and end() calls are not properly nested

getId() public method

Returns the ID of the widget.

public string|null getId ( $autoGenerate = true )
$autoGenerate | boolean | Whether to generate an ID if it is not set previously
return | string|null | ID of the widget.

getView() public method

Returns the view object that can be used to render views or view files.

The render() and renderFile() methods will use this view object to implement the actual view rendering. If not set, it will default to the "view" application component.

public yii\web\View getView ( )
return | yii\web\View | The view object that can be used to render views or view files.

getViewPath() public method

Returns the directory containing the view files for this widget.

The default implementation returns the 'views' subdirectory under the directory containing the widget class file.

public string getViewPath ( )
return | string | The directory containing the view files for this widget.

init() public method

Initializes the object.

This method is called at the end of the constructor. The default implementation will trigger an EVENT_INIT event.

public void init ( )

render() public method

Renders a view.

The view to be rendered can be specified in one of the following formats:

- path alias (e.g. "@app/views/site/index");
- absolute path within application (e.g. "//site/index"): the view name starts with double slashes. The actual view file will be looked for under the view path of the application.
- absolute path within module (e.g. "/site/index"): the view name starts with a single slash. The actual view file will be looked for under the view path of the currently active module.
- relative path (e.g. "index"): the actual view file will be looked for under $viewPath.

If the view name does not contain a file extension, it will use the default one `.php`.

public string render ( $view, $params = [] )
$view | string | The view name.
$params | array | The parameters (name-value pairs) that should be made available in the view.
return | string | The rendering result.
throws | yii\base\InvalidArgumentException | if the view file does not exist.

renderFile() public method

Renders a view file.

public string renderFile ( $file, $params = [] )
$file | string | The view file to be rendered. This can be either a file path or a path alias.
$params | array | The parameters (name-value pairs) that should be made available in the view.
return | string | The rendering result.
throws | yii\base\InvalidArgumentException | if the view file does not exist.

run() public method

Executes the widget.

public string run ( )
return | string | The result of widget execution to be outputted.

setId() public method

Sets the ID of the widget.

public void setId ( $value )
$value | string | Id of the widget.

setView() public method

Sets the view object to be used by this widget.

public void setView ( $view )
$view | yii\base\View | The view object that can be used to render views or view files.

widget() public static method

Creates a widget instance and runs it.

The widget rendering result is returned by this method.

public static string widget ( $config = [] )
$config | array | Name-value pairs that will be used to initialize the object properties
return | string | The rendering result of the widget.
throws | Exception |

## Event Details

EVENT_AFTER_RUN event of type yii\base\WidgetEvent (available since version 2.0.11)

An event raised right after executing a widget.

EVENT_BEFORE_RUN event of type yii\base\WidgetEvent (available since version 2.0.11)

An event raised right before executing a widget. You may set yii\base\WidgetEvent::$isValid to be false to cancel the widget execution.

EVENT_INIT event of type yii\base\Event (available since version 2.0.11)

An event that is triggered when the widget is initialized via init().