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Interface

BubblingEmitter (engine/view/observer)

@ckeditor/ckeditor5-engine/src/view/observer/bubblingemittermixin

interface
See source

Bubbling emitter for the view document.

Bubbling emitter is triggering events in the context of specified view element name, predefined '$text', '$root', '$document' and '$capture' contexts, and context matchers provided as a function.

Before bubbling starts, listeners for '$capture' context are triggered. Then the bubbling starts from the deeper selection position (by firing event on the '$text' context) and propagates the view document tree up to the '$root' and finally the listeners at '$document' context are fired (this is the default context).

Examples:

// Listeners registered in the context of the view element names:
this.listenTo( viewDocument, 'enter', ( evt, data ) => {
	// ...
}, { context: 'blockquote' } );

this.listenTo( viewDocument, 'enter', ( evt, data ) => {
	// ...
}, { context: 'li' } );

// Listeners registered in the context of the '$text' and '$root' nodes.
this.listenTo( view.document, 'arrowKey', ( evt, data ) => {
	// ...
}, { context: '$text', priority: 'high' } );

this.listenTo( view.document, 'arrowKey', ( evt, data ) => {
	// ...
}, { context: '$root' } );

// Listeners registered in the context of custom callback function.
this.listenTo( view.document, 'arrowKey', ( evt, data ) => {
	// ...
}, { context: isWidget } );

this.listenTo( view.document, 'arrowKey', ( evt, data ) => {
	// ...
}, { context: isWidget, priority: 'high' } );

Example flow for selection in text:

<blockquote><p>Foo[]bar</p></blockquote>

Fired events on contexts:

  1. '$capture'
  2. '$text'
  3. 'p'
  4. 'blockquote'
  5. '$root'
  6. '$document'

Example flow for selection on element (i.e., Widget):

<blockquote><p>Foo[<widget/>]bar</p></blockquote>

Fired events on contexts:

  1. '$capture'
  2. widget (custom matcher)
  3. 'p'
  4. 'blockquote'
  5. '$root'
  6. '$document'

There could be multiple listeners registered for the same context and at different priority levels:

<p>Foo[]bar</p>
  1. '$capture' at priorities:
    1. 'highest'
    2. 'high'
    3. 'normal'
    4. 'low'
    5. 'lowest'
  2. '$text' at priorities:
    1. 'highest'
    2. 'high'
    3. 'normal'
    4. 'low'
    5. 'lowest'
  3. 'p' at priorities:
    1. 'highest'
    2. 'high'
    3. 'normal'
    4. 'low'
    5. 'lowest'
  4. '$root' at priorities:
    1. 'highest'
    2. 'high'
    3. 'normal'
    4. 'low'
    5. 'lowest'
  5. '$document' at priorities:
    1. 'highest'
    2. 'high'
    3. 'normal'
    4. 'low'
    5. 'lowest'

Filtering

Methods

  • delegate( events ) → EmitterMixinDelegateChain

    inherited

    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

  • fire( eventOrInfo, [ args ] ) → *

    inherited

    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] } )

    inherited

    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 )

    inherited

    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] } )

    inherited

    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] } )

    inherited

    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 ] )

    inherited

    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 ] )

    inherited

    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.

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

    protected inherited

    Adds callback to emitter for given event.

    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 {}

  • _removeEventListener( event, callback )

    protected inherited

    Removes callback from emitter for given event.

    See source

    Parameters

    event : String

    The name of the event.

    callback : function

    The function to stop being called.