Widget

API reference › yii › base › Widget

class	`yii\base\Widget`
Extends	`Component` » `BaseObject`
Implements	`ViewContextInterface`, `Configurable`
Since	2.0
Source	`framework/base/Widget.php`

16 subclasses

Widget is the base class for widgets.

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

Properties

Property	Type	Description	Defined by
`$autoIdPrefix` static	`string`	The prefix to the automatically generated widget IDs. Default: `'w'`.	`Widget`
`$behaviors` read-only	`array<Behavior<static>>`	List of behaviors attached to this component.	`Component`
`$id`	`string`	Id of the widget.	`Widget`
`$view`	`yii\web\View`	The view object that can be used to render views or view files.	`Widget`
`$viewPath` read-only	`string`	The directory containing the view files for this widget.	`Widget`

Methods

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

Events

Event	Type	Description	Defined by
`EVENT_INIT`	`Event`	An event that is triggered when the widget is initialized via `init()`. Event name: `'init'`. Available since 2.0.11.	`Widget`
`EVENT_BEFORE_RUN`	`WidgetEvent`	An event raised right before executing a widget. Event name: `'beforeRun'`. Available since 2.0.11.	`Widget`
`EVENT_AFTER_RUN`	`WidgetEvent`	An event raised right after executing a widget. Event name: `'afterRun'`. Available since 2.0.11.	`Widget`

Method details

afterRun()

public function afterRun(mixed $result): mixed

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;
}

Parameters

Parameter	Type	Description
`$result`	`mixed`	The widget return result.

Returns

mixed: The processed widget result.

Since

2.0.11

beforeRun()

public function beforeRun(): bool

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
}

Returns

bool: Whether the widget should continue to be executed.

Since

2.0.11

begin()

public static function begin(array $config = []): static

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.

Parameters

Parameter	Type	Description
`$config`	`array`	Name-value pairs that will be used to initialize the object properties

Returns

static: The newly created widget instance

See also

end()

end()

public static function end(): static

Ends a widget.

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

Returns

static: The widget instance that is ended.

Throws

InvalidCallException: if begin() and end() calls are not properly nested

See also

begin()

getId()

public function getId(bool $autoGenerate = true): string|null

Returns the ID of the widget.

Parameters

Parameter	Type	Description
`$autoGenerate`	`bool`	Whether to generate an ID if it is not set previously

Returns

string|null: ID of the widget.

getView()

public function getView(): yii\web\View

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.

Returns

yii\web\View: The view object that can be used to render views or view files.

getViewPath()

public function getViewPath(): string

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.

Returns

string: The directory containing the view files for this widget.

init()

public function init(): mixed

Initializes the object.

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

Returns

mixed

render()

public function render(string $view, array $params = []): string

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.

Parameters

Parameter	Type	Description
`$view`	`string`	The view name.
`$params`	`array`	The parameters (name-value pairs) that should be made available in the view.

Returns

string: The rendering result.

Throws

InvalidArgumentException: if the view file does not exist.

renderFile()

public function renderFile(string $file, array $params = []): string

Renders a view file.

Parameters

Parameter	Type	Description
`$file`	`string`	The view file to be rendered. This can be either a file path or a path alias.
`$params`	`array`	The parameters (name-value pairs) that should be made available in the view.

Returns

string: The rendering result.

Throws

InvalidArgumentException: if the view file does not exist.

run()

public function run(): string|void

Executes the widget.

Returns

string|void: The rendering result may be directly “echoed” or returned as a string

setId()

public function setId(string $value): mixed

Sets the ID of the widget.

Parameters

Parameter	Type	Description
`$value`	`string`	Id of the widget.

Returns

mixed

setView()

public function setView(yii\web\View $view): mixed

Sets the view object to be used by this widget.

Parameters

Parameter	Type	Description
`$view`	`yii\web\View`	The view object that can be used to render views or view files.

Returns

mixed

public static function widget(array $config = []): string

Creates a widget instance and runs it.

The widget rendering result is returned by this method.

Parameters

Parameter	Type	Description
`$config`	`array`	Name-value pairs that will be used to initialize the object properties

Returns

string: The rendering result of the widget.

Throws

Throwable

Widget

Properties

Methods

Events

Method details

afterRun()

beforeRun()

begin()

end()

getId()

getView()

getViewPath()

init()

render()

renderFile()

run()

setId()

setView()

widget()