DomEventObserver

A reference to the ViewDocument object.

Type of the DOM event the observer should listen to. Array of types can be defined if the observer should listen to multiple DOM events.

The state of the observer. If it is disabled, no events will be fired.

If set to true DOM events will be listened on the capturing phase. Default value is false.

If set to true, indicates that the function specified by listener will never call preventDefault(). Default value is false.

An instance of the view controller.

Creates an instance of the observer.

Type parameters

EventType: extends keyof HTMLElementEventMap

DOM Event type name or an union of those.

AdditionalData: extends object = object

Additional data passed along with the event.

Parameters

view: EditingView

Checks whether a given DOM event should be ignored (should not be turned into a synthetic view document event).

Currently, an event will be ignored only if its target or any of its ancestors has the data-cke-ignore-events attribute. This attribute can be used inside the structures generated by ViewDowncastWriter#createUIElement() to ignore events fired within a UI that should be excluded from CKEditor 5's realms.

Parameters

domTarget: Node | null

The DOM event target to check (usually an element, sometimes a text node and potentially sometimes a document, too).

Returns

boolean

Whether this event should be ignored by the observer.

Delegates selected events to another Emitter. For instance:

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: Array<string>

Event names that will be delegated to another emitter.

Returns

EmitterMixinDelegateChain

Disables and destroys the observer, among others removes event listeners created by the observer.

Returns

void

Disables the observer. This method is called before rendering to prevent firing events during rendering.

Returns

void

Related:

• Observer#enable

Enables the observer. This method is called when the observer is registered to the EditingView and after rendering (all observers are disabled before rendering).

A typical use case for disabling observers is that mutation observers need to be disabled for the rendering. However, a child class may not need to be disabled, so it can implement an empty method.

Returns

void

Related:

• Observer#disable

Calls Document#fire() if observer is enabled.

Parameters

eventType: string | EventInfo<string, unknown>

The event type (name).

domEvent: Event

The DOM event.

additionalData?: AdditionalData

The additional data which should extend the event data object.

Returns

void

Related:

• Emitter#fire

Registers 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 fire method.

Type parameters

TEvent: extends BaseEvent

The type describing the event. See BaseEvent.

Parameters

emitter: Emitter

The object that fires the event.

event: TEvent[ 'name' ]

The name of the event.

callback: GetCallback<TEvent>

The function to be called on event.

options?: CallbackOptions

Additional options.

Returns

void

Registers 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 fire method.

Type parameters

TEvent: extends BaseEvent

The type describing the event. See BaseEvent.

Parameters

emitter: Emitter

The object that fires the event.

event: TEvent[ 'name' ]

The name of the event.

callback: GetCallback<TEvent>

The function to be called on event.

options?: GetCallbackOptions<TEvent>

Additional options.

Returns

void

Registers a callback function to be executed when an event is fired in a specific Emitter or DOM Node. It is backwards compatible with listenTo.

Type parameters

K: extends keyof DomEventMap

Parameters

emitter: Window | EventTarget | Node

The object that fires the event.

event: K

The name of the event.

callback: ( this: this, ev: EventInfo, event: DomEventMap[ K ] ) => void

The function to be called on event.

options?: CallbackOptions & object

Additional options.

Returns

void

Starts observing given DOM element.

Parameters

domElement: HTMLElement

DOM element to observe.

Returns

void

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

Parameters

event: string

The name of the event.

callback: Function

The function to stop being called.

Returns

void

Registers 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).

Type parameters

TEvent: extends BaseEvent

The type descibing the event. See BaseEvent.

Parameters

event: TEvent[ 'name' ]

The name of the event.

callback: GetCallback<TEvent>

The function to be called on event.

options?: GetCallbackOptions<TEvent>

Additional options.

Returns

void

Callback which should be called when the DOM event occurred. Note that the callback will not be called if observer is not enabled.

Parameters

event: HTMLElementEventMap[ EventType ]

Returns

void

Related:

• DomEventObserver#domEventType

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.

Type parameters

TEvent: extends BaseEvent

The type descibing the event. See BaseEvent.

Parameters

event: TEvent[ 'name' ]

The name of the event.

callback: GetCallback<TEvent>

The function to be called on event.

options?: GetCallbackOptions<TEvent>

Additional options.

Returns

void

Stops 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?: 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.

Returns

void

Stops 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?: 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.

Returns

void

Stops listening for events. It can be used at different levels: It is backwards compatible with listenTo.

• 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?: Window | EventTarget | Node | 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.

Returns

void

Stops observing given DOM element.

Parameters

domElement: HTMLElement

Returns

void