EmitterMixin (utils/dom)
@ckeditor/ckeditor5-utils/src/dom/emittermixin
Mixin that injects the DOM events API into its host. It provides the API
compatible with EmitterMixin.
DOM emitter mixin is by default available in the View class,
but it can also be mixed into any other class:
import mix from '../utils/mix.js';
import DomEmitterMixin from '../utils/dom/emittermixin.js';
class SomeView {}
mix( SomeView, DomEmitterMixin );
const view = new SomeView();
view.listenTo( domElement, ( evt, domEvt ) => {
console.log( evt, domEvt );
} );
Filtering
Methods
-
mixed
delegate( events ) → EmitterMixinDelegateChainmodule:utils/dom/emittermixin~EmitterMixin#delegateDelegates selected events to another
Emitter. For instance:emitterA.delegate( 'eventX' ).to( emitterB ); emitterA.delegate( 'eventX', 'eventY' ).to( emitterC );then
eventXis delegated (fired by)emitterBandemitterCalong withdata:emitterA.fire( 'eventX', data );and
eventYis delegated (fired by)emitterCalong withdata:emitterA.fire( 'eventY', data );Parameters
events : StringEvent names that will be delegated to another emitter.
Returns
-
Fires an event, executing all callbacks registered for it.
The first parameter passed to callbacks is an
EventInfoobject, followed by the optionalargsprovided in thefire()method call.Parameters
eventOrInfo : String | EventInfoThe name of the event or
EventInfoobject if event is delegated.[ args ] : *Additional arguments to be passed to the callbacks.
Returns
*By default the method returns
undefined. However, the return value can be changed by listeners through modification of theevt.return's property (the event info is the first param of every callback).
-
mixed
listenTo( emitter, event, callback, [ options ] = { [options.priority] } )module:utils/dom/emittermixin~EmitterMixin#listenToRegisters a callback function to be executed when an event is fired in a specific (emitter) object.
Events can be grouped in namespaces using
:. When namespaced event is fired, it additionally fires all callbacks for that namespace.// myEmitter.on( ... ) is a shorthand for myEmitter.listenTo( myEmitter, ... ). myEmitter.on( 'myGroup', genericCallback ); myEmitter.on( 'myGroup:myEvent', specificCallback ); // genericCallback is fired. myEmitter.fire( 'myGroup' ); // both genericCallback and specificCallback are fired. myEmitter.fire( 'myGroup:myEvent' ); // genericCallback is fired even though there are no callbacks for "foo". myEmitter.fire( 'myGroup:foo' );An event callback can stop the event and set the return value of the
firemethod.Parameters
emitter : EmitterThe object that fires the event.
event : StringThe name of the event.
callback : functionThe function to be called on event.
[ options ] : ObjectAdditional options.
Properties[ options.priority ] : PriorityString | NumberThe priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.
Defaults to
'normal'
Defaults to
{}
-
Stops executing the callback on the given event. Shorthand for
this.stopListening( this, event, callback ).Parameters
event : StringThe name of the event.
callback : functionThe function to stop being called.
-
mixed
on( event, callback, [ options ] = { [options.priority] } )module:utils/dom/emittermixin~EmitterMixin#onRegisters a callback function to be executed when an event is fired.
Shorthand for
this.listenTo( this, event, callback, options )(it makes the emitter listen on itself).Parameters
event : StringThe name of the event.
callback : functionThe function to be called on event.
[ options ] : ObjectAdditional options.
Properties[ options.priority ] : PriorityString | NumberThe priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.
Defaults to
'normal'
Defaults to
{}
-
mixed
once( event, callback, [ options ] = { [options.priority] } )module:utils/dom/emittermixin~EmitterMixin#onceRegisters a callback function to be executed on the next time the event is fired only. This is similar to calling
onfollowed byoffin the callback.Parameters
event : StringThe name of the event.
callback : functionThe function to be called on event.
[ options ] : ObjectAdditional options.
Properties[ options.priority ] : PriorityString | NumberThe priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.
Defaults to
'normal'
Defaults to
{}
-
mixed
stopDelegating( [ event ], [ emitter ] )module:utils/dom/emittermixin~EmitterMixin#stopDelegatingStops delegating events. It can be used at different levels:
- To stop delegating all events.
- To stop delegating a specific event to all emitters.
- To stop delegating a specific event to a specific emitter.
Parameters
[ event ] : StringThe name of the event to stop delegating. If omitted, stops it all delegations.
[ emitter ] : Emitter(requires
event) The object to stop delegating a particular event to. If omitted, stops delegation ofeventto all emitters.
-
mixed
stopListening( [ emitter ], [ event ], [ callback ] )module:utils/dom/emittermixin~EmitterMixin#stopListeningStops listening for events. It can be used at different levels:
- To stop listening to a specific callback.
- To stop listening to a specific event.
- To stop listening to all events fired by a specific object.
- To stop listening to all events fired by all objects.
Parameters
[ emitter ] : EmitterThe object to stop listening to. If omitted, stops it for all objects.
[ event ] : String(Requires the
emitter) The name of the event to stop listening to. If omitted, stops it for all events fromemitter.[ callback ] : function(Requires the
event) The function to be removed from the call list for the givenevent.
-
protected mixed
_addEventListener( event, callback, [ options ] = { [options.priority] } )module:utils/dom/emittermixin~EmitterMixin#_addEventListenerAdds callback to emitter for given event.
Parameters
event : StringThe name of the event.
callback : functionThe function to be called on event.
[ options ] : ObjectAdditional options.
Properties[ options.priority ] : PriorityString | NumberThe priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.
Defaults to
'normal'
Defaults to
{}
-
protected mixed
_removeEventListener( event, callback )module:utils/dom/emittermixin~EmitterMixin#_removeEventListenerRemoves callback from emitter for given event.
Parameters
event : StringThe name of the event.
callback : functionThe function to stop being called.
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