Class: EventBus
@ima/core.EventBus
Utility for sending and intercepting wrapped custom DOM events on the DOM or propagating them to the current controller.
As with native events, the event fired by this event bus always propagate up the DOM tree until they reach the window.
Note that the events fired by this event bus are wrapped in custom DOM events which always bear an obscure name set by the implementation of this interface, preventing custom event name collisions, and allowing observation and capture of all fired events. The actual event name is always consistent by the implementation.
Hierarchy
EventBus
Constructors
constructor
• new EventBus()
Methods
fire
▸ fire(eventTarget, eventName, data?, options?): EventBus
Fires a new custom event of the specified name, carrying the provided data.
Note that this method does not prevent the event listeners to modify the data in any way. The order in which the event listeners will be executed is unspecified and should not be relied upon.
Note that the default options are
{ bubbles: true, cancelable: true }, which is different from the
default values used in the native custom events
({ bubbles: false, cancelable: false }).
Parameters
| Name | Type | Description |
|---|---|---|
eventTarget | EventTarget | The event target at which the event will be dispatched (e.g. element/document/window). |
eventName | string | The name of the event to fire. |
data? | any | The data to pass to the event listeners. |
options? | EventBusOptions | The override of the default options passed to the constructor of the custom event fired by this event bus. The default options passed to the custom event constructor are { bubbles: true, cancelable: true }. |
Returns
This custom event bus.
Throws
Thrown if the provided event target cannot be used to fire the event.
See
https://developer.mozilla.org/en-US/docs/Web/API/Event/Event
Defined in
packages/core/src/event/EventBus.ts:56
listen
▸ listen(eventTarget, eventName, listener): EventBus
Registers the provided event listener to be executed when the specific custom event is fired by the same implementation of the event bus and passes through the specified event target.
When the specified event is fired, the event listener will be executed with the event passed as the first argument.
The order in which the event listeners will be executed is unspecified and should not be relied upon.
Parameters
| Name | Type | Description |
|---|---|---|
eventTarget | EventTarget | The event target at which the listener should listen for the specified event. |
eventName | string | The name of the event to listen for. |
listener | EventBusListener | The event listener to register. |
Returns
This event bus.
Defined in
packages/core/src/event/EventBus.ts:104
listenAll
▸ listenAll(eventTarget, listener): EventBus
Registers the provided event listener to be executed when any custom event is fired using the same implementation of the event bus and passes through the specified event target.
When the specified event is fired, the event listener will be executed with the event passed as the first argument.
The order in which the event listeners will be executed is unspecified and should not be relied upon.
Parameters
| Name | Type | Description |
|---|---|---|
eventTarget | EventTarget | The event target at which the listener should listen for all event bus events. |
listener | EventBusListener | The event listener to register. |
Returns
This event bus.
Defined in
packages/core/src/event/EventBus.ts:82
unlisten
▸ unlisten(eventTarget, eventName, listener): EventBus
Removes the provided event listener from the set of event listeners executed when the specified custom event fired by the same implementation passes through the specified event target.
The method has no effect if the listener is not registered for the specified event at the specified event target.
Parameters
| Name | Type | Description |
|---|---|---|
eventTarget | EventTarget | The event target at which the listener is listening for the event. |
eventName | string | The name of the event listened for. |
listener | EventBusListener | The event listener to deregister. |
Returns
This event bus.
Defined in
packages/core/src/event/EventBus.ts:145
unlistenAll
▸ unlistenAll(eventTarget, listener): EventBus
Removes the provided event listener from the set of event listeners executed when the any custom event fired by the same implementation passes through the specified event target.
The method has no effect if the listener is not registered at the specified event target.
Parameters
| Name | Type | Description |
|---|---|---|
eventTarget | EventTarget | The event target at which the event listener listens for events. |
listener | EventBusListener | The event listener to deregister. |
Returns
This event bus.