Event
- Type
- Class
- Namespace
- craft\base
- Inherits
- craft\base\Event » yii\base\Event (opens new window) » yii\base\BaseObject (opens new window)
- Implements
- yii\base\Configurable (opens new window)
- Since
- 4.4.0
ElementTrait implements the common methods and properties for element classes.
View source (opens new window)
# Public Properties
| Property | Description |
|---|---|
| data (opens new window) | mixed – The data that is passed to yii\base\Component::on() (opens new window) when attaching an event handler. |
| handled (opens new window) | boolean (opens new window) – Whether the event is handled. |
| name (opens new window) | string (opens new window) – The event name. |
| sender (opens new window) | object (opens new window), null (opens new window) – The sender of this event. |
# Public Methods
| Method | Description |
|---|---|
| __call() (opens new window) | Calls the named method which is not a class method. |
| __construct() (opens new window) | Constructor. |
| __get() (opens new window) | Returns the value of an object property. |
| __isset() (opens new window) | Checks if a property is set, i.e. defined and not null. |
| __set() (opens new window) | Sets value of an object property. |
| __unset() (opens new window) | Sets an object property to null. |
| canGetProperty() (opens new window) | Returns a value indicating whether a property can be read. |
| canSetProperty() (opens new window) | Returns a value indicating whether a property can be set. |
| className() (opens new window) | Returns the fully qualified name of this class. |
| hasHandlers() (opens new window) | Returns a value indicating whether there is any handler attached to the specified class-level event. |
| hasMethod() (opens new window) | Returns a value indicating whether a method is defined. |
| hasProperty() (opens new window) | Returns a value indicating whether a property is defined. |
| init() (opens new window) | Initializes the object. |
| off() (opens new window) | Detaches an event handler from a class-level event. |
| offAll() (opens new window) | Detaches all registered class-level event handlers. |
| on() (opens new window) | Attaches an event handler to a class-level event. |
| once() | Attaches an event handler to a class-level event, which will be triggered at most one time. |
| trigger() (opens new window) | Triggers a class-level event. |
# once()
Attaches an event handler to a class-level event, which will be triggered at most one time.
See also on() (opens new window) View source (opens new window)
Arguments
$class(string (opens new window)) – The fully qualified class name to which the event handler needs to attach.$name(string (opens new window)) – The event name.$handler(callable (opens new window)) – The event handler.$data(mixed) – The data to be passed to the event handler when the event is triggered. When the event handler is invoked, this data can be accessed via yii\base\Event::$data (opens new window).$append(boolean (opens new window)) – Whether to append new event handler to the end of the existing handler list. Iffalse, the new handler will be inserted at the beginning of the existing handler list.