CKEditor Ecosystem Documentation
Search
Home/CKEditor 5/API
Class

ProxyEmitter (utils/dom)

@ckeditor/ckeditor5-utils/src/dom/emittermixin

class private
See source

Creates a ProxyEmitter instance. Such an instance is a bridge between a DOM Node firing events and any Host listening to them. It is backwards compatible with on.

                         listenTo( click, ... )
           +-----------------------------------------+
           |              stopListening( ... )       |
+----------------------------+                           |             addEventListener( click, ... )
| Host                       |                           |   +---------------------------------------------+
+----------------------------+                           |   |       removeEventListener( click, ... )     |
| _listeningTo: {            |                +----------v-------------+                                   |
|   UID: {                   |                | ProxyEmitter           |                                   |
|     emitter: ProxyEmitter, |                +------------------------+                      +------------v----------+
|     callbacks: {           |                | events: {              |                      | Node (HTMLElement)    |
|       click: [ callbacks ] |                |   click: [ callbacks ] |                      +-----------------------+
|     }                      |                | },                     |                      | data-ck-expando: UID  |
|   }                        |                | _domNode: Node,        |                      +-----------------------+
| }                          |                | _domListeners: {},     |                                   |
| +------------------------+ |                | _emitterId: UID        |                                   |
| | DomEmitterMixin        | |                +--------------^---------+                                   |
| +------------------------+ |                           |   |                                             |
+--------------^-------------+                           |   +---------------------------------------------+
           |                                         |                  click (DOM Event)
           +-----------------------------------------+
                       fire( click, DOM Event )

Filtering

Properties

  • _domListeners : Object

    private

    Collection of native DOM listeners.

    See source

Methods

  • constructor( node ) → Object

    Parameters

    node : Node

    DOM Node that fires events.

    Returns

    Object

    ProxyEmitter instance bound to the DOM Node.

  • attach( event, callback, [ options ] = { [options.useCapture] } )

    Registers a callback function to be executed when an event is fired.

    See source

    It attaches a native DOM listener to the DOM Node. When fired, a corresponding Emitter event will also fire with DOM Event object as an argument.

    Parameters

    event : String

    The name of the event.

    callback : function

    The function to be called on event.

    [ options ] : Object

    Additional options.

    Properties
    [ options.useCapture ] : Boolean

    Indicates that events of this type will be dispatched to the registered listener before being dispatched to any EventTarget beneath it in the DOM tree.

    Defaults to false

    Defaults to {}

  • delegate( events ) → EmitterMixinDelegateChain

    mixed

    Delegates selected events to another Emitter. For instance:

    See source
    emitterA.delegate( 'eventX' ).to( emitterB );
emitterA.delegate( 'eventX', 'eventY' ).to( emitterC );

    then eventX is delegated (fired by) emitterB and emitterC along with data:

    emitterA.fire( 'eventX', data );

    and eventY is delegated (fired by) emitterC along with data:

    emitterA.fire( 'eventY', data );

    Parameters

    events : String

    Event names that will be delegated to another emitter.

    Returns

    EmitterMixinDelegateChain

  • detach( event )

    Stops executing the callback on the given event.

    See source

    Parameters

    event : String

    The name of the event.

  • fire( eventOrInfo, [ args ] ) → *

    mixed

    Fires an event, executing all callbacks registered for it.

    See source

    The first parameter passed to callbacks is an EventInfo object, followed by the optional args provided in the fire() method call.

    Parameters

    eventOrInfo : String | EventInfo

    The name of the event or EventInfo object 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 the evt.return's property (the event info is the first param of every callback).

  • listenTo( emitter, event, callback, [ options ] = { [options.priority] } )

    mixed

    Registers a callback function to be executed when an event is fired in a specific (emitter) object.

    See source

    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 fire method.

    Parameters

    emitter : Emitter

    The object that fires the event.

    event : String

    The name of the event.

    callback : function

    The function to be called on event.

    [ options ] : Object

    Additional options.

    Properties
    [ options.priority ] : PriorityString | Number

    The 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 {}

  • off( event, callback )

    mixed

    Stops executing the callback on the given event. Shorthand for this.stopListening( this, event, callback ).

    See source

    Parameters

    event : String

    The name of the event.

    callback : function

    The function to stop being called.

  • on( event, callback, [ options ] = { [options.priority] } )

    mixed

    Registers a callback function to be executed when an event is fired.

    See source

    Shorthand for this.listenTo( this, event, callback, options ) (it makes the emitter listen on itself).

    Parameters

    event : String

    The name of the event.

    callback : function

    The function to be called on event.

    [ options ] : Object

    Additional options.

    Properties
    [ options.priority ] : PriorityString | Number

    The 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 {}

  • once( event, callback, [ options ] = { [options.priority] } )

    mixed

    Registers a callback function to be executed on the next time the event is fired only. This is similar to calling on followed by off in the callback.

    See source

    Parameters

    event : String

    The name of the event.

    callback : function

    The function to be called on event.

    [ options ] : Object

    Additional options.

    Properties
    [ options.priority ] : PriorityString | Number

    The 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 {}

  • stopDelegating( [ event ], [ emitter ] )

    mixed

    Stops delegating events. It can be used at different levels:

    See source
    • 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 ] : String

    The 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 of event to all emitters.

  • stopListening( [ emitter ], [ event ], [ callback ] )

    mixed

    Stops listening for events. It can be used at different levels:

    See source
    • 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 ] : Emitter

    The 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 from emitter.

    [ callback ] : function

    (Requires the event) The function to be removed from the call list for the given event.

  • _createDomListener( event, useCapture ) → function

    private

    Creates a native DOM listener callback. When the native DOM event is fired it will fire corresponding event on this ProxyEmitter. Note: A native DOM Event is passed as an argument.

    See source

    Parameters

    event : String

    The name of the event.

    useCapture : Boolean

    Indicates whether the listener was created for capturing event.

    Returns

    function

    The DOM listener callback.