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Class

BalloonEditorUI (editor-balloon)

@ckeditor/ckeditor5-editor-balloon/src/ballooneditorui

class
See source

The balloon editor UI class.

Filtering

Properties

  • deprecated readonly inherited

    _editableElements : unknown

    See source

    Stores all editable elements used by the editor instance.

  • readonly inherited

    ariaLiveAnnouncer : AriaLiveAnnouncer

    See source

    A helper that manages the content of an aria-live regions used by editor features to announce status changes to screen readers.

  • readonly inherited

    componentFactory : ComponentFactory

    See source

    An instance of the ComponentFactory, a registry used by plugins to register factories of specific UI components.

  • readonly inherited

    editor : Editor

    See source

    The editor that the UI belongs to.

  • readonly

    element : null | HTMLElement

    See source

    The main (outermost) DOM element of the editor UI.

    For example, in ClassicEditor it is a <div> which wraps the editable element and the toolbar. In InlineEditor it is the editable element itself (as there is no other wrapper). However, in DecoupledEditor it is set to null because this editor does not come with a single "main" HTML element (its editable element and toolbar are separate).

    This property can be understood as a shorthand for retrieving the element that a specific editor integration considers to be its main DOM element.

  • readonly inherited

    focusTracker : FocusTracker

    See source

    Stores the information about the editor UI focus and propagates it so various plugins and components are unified as a focus group.

  • inherited

    isReady : boolean

    See source

    Indicates the UI is ready. Set true after event-ready event is fired.

    Defaults to false

  • readonly inherited

    poweredBy : PoweredBy

    See source

    A helper that enables the "powered by" feature in the editor and renders a link to the project's webpage.

  • readonly inherited

    tooltipManager : TooltipManager

    See source

    Manages the tooltips displayed on mouseover and focus across the UI.

  • readonly

    view : BalloonEditorUIView

    See source

    The main (top–most) view of the editor UI.

  • inherited observable

    viewportOffset : object

    See source

    Stores viewport offsets from every direction.

    Viewport offset can be used to constrain balloons or other UI elements into an element smaller than the viewport. This can be useful if there are any other absolutely positioned elements that may interfere with editor UI.

    Example editor.ui.viewportOffset returns:

    {
	top: 50,
	right: 50,
	bottom: 50,
	left: 50
}

    This property can be overriden after editor already being initialized:

    editor.ui.viewportOffset = {
	top: 100,
	right: 0,
	bottom: 0,
	left: 0
};

Methods

  • constructor( editor, view )

    See source

    Creates an instance of the balloon editor UI class.

    Parameters

    editor : Editor

    The editor instance.

    view : BalloonEditorUIView

    The view of the UI.

  • inherited

    addToolbar( toolbarView, options ) → void

    See source

    Adds a toolbar to the editor UI. Used primarily to maintain the accessibility of the UI.

    Focusable toolbars can be accessed (focused) by users by pressing the Alt + F10 keystroke. Successive keystroke presses navigate over available toolbars.

    Parameters

    toolbarView : ToolbarView

    A instance of the toolbar to be registered.

    options : FocusableToolbarOptions

    Defaults to {}

    Returns

    void

  • inherited

    bind( bindProperty1, bindProperty2 ) → DualBindChain<K1, BalloonEditorUI[ K1 ], K2, BalloonEditorUI[ K2 ]>

    See source

    Binds observable properties to other objects implementing the Observable interface.

    Read more in the dedicated guide covering the topic of property bindings with some additional examples.

    Consider two objects: a button and an associated command (both Observable).

    A simple property binding could be as follows:

    button.bind( 'isEnabled' ).to( command, 'isEnabled' );

    or even shorter:

    button.bind( 'isEnabled' ).to( command );

    which works in the following way:

    • button.isEnabled instantly equals command.isEnabled,
    • whenever command.isEnabled changes, button.isEnabled will immediately reflect its value.

    Note: To release the binding, use unbind.

    You can also "rename" the property in the binding by specifying the new name in the to() chain:

    button.bind( 'isEnabled' ).to( command, 'isWorking' );

    It is possible to bind more than one property at a time to shorten the code:

    button.bind( 'isEnabled', 'value' ).to( command );

    which corresponds to:

    button.bind( 'isEnabled' ).to( command );
button.bind( 'value' ).to( command );

    The binding can include more than one observable, combining multiple data sources in a custom callback:

    button.bind( 'isEnabled' ).to( command, 'isEnabled', ui, 'isVisible',
	( isCommandEnabled, isUIVisible ) => isCommandEnabled && isUIVisible );

    Using a custom callback allows processing the value before passing it to the target property:

    button.bind( 'isEnabled' ).to( command, 'value', value => value === 'heading1' );

    It is also possible to bind to the same property in an array of observables. To bind a button to multiple commands (also Observables) so that each and every one of them must be enabled for the button to become enabled, use the following code:

    button.bind( 'isEnabled' ).toMany( [ commandA, commandB, commandC ], 'isEnabled',
	( isAEnabled, isBEnabled, isCEnabled ) => isAEnabled && isBEnabled && isCEnabled );

    Type parameters

    K1
    K2

    Parameters

    bindProperty1 : K1

    Observable property that will be bound to other observable(s).

    bindProperty2 : K2

    Observable property that will be bound to other observable(s).

    Returns

    DualBindChain<K1, BalloonEditorUI[ K1 ], K2, BalloonEditorUI[ K2 ]>

    The bind chain with the to() and toMany() methods.

  • inherited

    bind( bindProperties ) → MultiBindChain

    See source

    Binds observable properties to other objects implementing the Observable interface.

    Read more in the dedicated guide covering the topic of property bindings with some additional examples.

    Consider two objects: a button and an associated command (both Observable).

    A simple property binding could be as follows:

    button.bind( 'isEnabled' ).to( command, 'isEnabled' );

    or even shorter:

    button.bind( 'isEnabled' ).to( command );

    which works in the following way:

    • button.isEnabled instantly equals command.isEnabled,
    • whenever command.isEnabled changes, button.isEnabled will immediately reflect its value.

    Note: To release the binding, use unbind.

    You can also "rename" the property in the binding by specifying the new name in the to() chain:

    button.bind( 'isEnabled' ).to( command, 'isWorking' );

    It is possible to bind more than one property at a time to shorten the code:

    button.bind( 'isEnabled', 'value' ).to( command );

    which corresponds to:

    button.bind( 'isEnabled' ).to( command );
button.bind( 'value' ).to( command );

    The binding can include more than one observable, combining multiple data sources in a custom callback:

    button.bind( 'isEnabled' ).to( command, 'isEnabled', ui, 'isVisible',
	( isCommandEnabled, isUIVisible ) => isCommandEnabled && isUIVisible );

    Using a custom callback allows processing the value before passing it to the target property:

    button.bind( 'isEnabled' ).to( command, 'value', value => value === 'heading1' );

    It is also possible to bind to the same property in an array of observables. To bind a button to multiple commands (also Observables) so that each and every one of them must be enabled for the button to become enabled, use the following code:

    button.bind( 'isEnabled' ).toMany( [ commandA, commandB, commandC ], 'isEnabled',
	( isAEnabled, isBEnabled, isCEnabled ) => isAEnabled && isBEnabled && isCEnabled );

    Parameters

    bindProperties : Array<'off' | 'on' | 'once' | 'listenTo' | 'stopListening' | 'fire' | 'delegate' | 'stopDelegating' | 'set' | 'bind' | 'unbind' | 'decorate' | 'element' | 'view' | 'viewportOffset' | 'destroy' | 'focusTracker' | 'update' | 'poweredBy' | 'init' | 'componentFactory' | 'editor' | 'tooltipManager' | 'ariaLiveAnnouncer' | 'isReady' | 'setEditableElement' | 'removeEditableElement' | 'getEditableElement' | 'getEditableElementsNames' | 'addToolbar' | 'extendMenuBar'>

    Observable properties that will be bound to other observable(s).

    Returns

    MultiBindChain

    The bind chain with the to() and toMany() methods.

  • inherited

    bind( bindProperty ) → SingleBindChain<K, BalloonEditorUI[ K ]>

    See source

    Binds observable properties to other objects implementing the Observable interface.

    Read more in the dedicated guide covering the topic of property bindings with some additional examples.

    Consider two objects: a button and an associated command (both Observable).

    A simple property binding could be as follows:

    button.bind( 'isEnabled' ).to( command, 'isEnabled' );

    or even shorter:

    button.bind( 'isEnabled' ).to( command );

    which works in the following way:

    • button.isEnabled instantly equals command.isEnabled,
    • whenever command.isEnabled changes, button.isEnabled will immediately reflect its value.

    Note: To release the binding, use unbind.

    You can also "rename" the property in the binding by specifying the new name in the to() chain:

    button.bind( 'isEnabled' ).to( command, 'isWorking' );

    It is possible to bind more than one property at a time to shorten the code:

    button.bind( 'isEnabled', 'value' ).to( command );

    which corresponds to:

    button.bind( 'isEnabled' ).to( command );
button.bind( 'value' ).to( command );

    The binding can include more than one observable, combining multiple data sources in a custom callback:

    button.bind( 'isEnabled' ).to( command, 'isEnabled', ui, 'isVisible',
	( isCommandEnabled, isUIVisible ) => isCommandEnabled && isUIVisible );

    Using a custom callback allows processing the value before passing it to the target property:

    button.bind( 'isEnabled' ).to( command, 'value', value => value === 'heading1' );

    It is also possible to bind to the same property in an array of observables. To bind a button to multiple commands (also Observables) so that each and every one of them must be enabled for the button to become enabled, use the following code:

    button.bind( 'isEnabled' ).toMany( [ commandA, commandB, commandC ], 'isEnabled',
	( isAEnabled, isBEnabled, isCEnabled ) => isAEnabled && isBEnabled && isCEnabled );

    Type parameters

    K

    Parameters

    bindProperty : K

    Observable property that will be bound to other observable(s).

    Returns

    SingleBindChain<K, BalloonEditorUI[ K ]>

    The bind chain with the to() and toMany() methods.

  • inherited

    decorate( methodName ) → void

    See source

    Turns the given methods of this object into event-based ones. This means that the new method will fire an event (named after the method) and the original action will be plugged as a listener to that event.

    Read more in the dedicated guide covering the topic of decorating methods with some additional examples.

    Decorating the method does not change its behavior (it only adds an event), but it allows to modify it later on by listening to the method's event.

    For example, to cancel the method execution the event can be stopped:

    class Foo extends ObservableMixin() {
	constructor() {
		super();
		this.decorate( 'method' );
	}

	method() {
		console.log( 'called!' );
	}
}

const foo = new Foo();
foo.on( 'method', ( evt ) => {
	evt.stop();
}, { priority: 'high' } );

foo.method(); // Nothing is logged.

    Note: The high priority listener has been used to execute this particular callback before the one which calls the original method (which uses the "normal" priority).

    It is also possible to change the returned value:

    foo.on( 'method', ( evt ) => {
	evt.return = 'Foo!';
} );

foo.method(); // -> 'Foo'

    Finally, it is possible to access and modify the arguments the method is called with:

    method( a, b ) {
	console.log( `${ a }, ${ b }`  );
}

// ...

foo.on( 'method', ( evt, args ) => {
	args[ 0 ] = 3;

	console.log( args[ 1 ] ); // -> 2
}, { priority: 'high' } );

foo.method( 1, 2 ); // -> '3, 2'

    Parameters

    methodName : 'off' | 'on' | 'once' | 'listenTo' | 'stopListening' | 'fire' | 'delegate' | 'stopDelegating' | 'set' | 'bind' | 'unbind' | 'decorate' | 'element' | 'view' | 'viewportOffset' | 'destroy' | 'focusTracker' | 'update' | 'poweredBy' | 'init' | 'componentFactory' | 'editor' | 'tooltipManager' | 'ariaLiveAnnouncer' | 'isReady' | 'setEditableElement' | 'removeEditableElement' | 'getEditableElement' | 'getEditableElementsNames' | 'addToolbar' | 'extendMenuBar'

    Name of the method to decorate.

    Returns

    void

  • inherited

    delegate( events ) → EmitterMixinDelegateChain

    See source

    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

  • destroy() → void

    See source

    Destroys the UI.

    Returns

    void

  • inherited

    extendMenuBar( config ) → void

    See source

    Registers an extra menu bar element, which could be a single item, a group of items, or a menu containing groups.

    // Register a new menu bar item.
editor.ui.extendMenuBar( {
  item: 'menuBar:customFunctionButton',
  position: 'after:menuBar:bold'
} );

// Register a new menu bar group.
editor.ui.extendMenuBar( {
  group: {
    groupId: 'customGroup',
    items: [
      'menuBar:customFunctionButton'
    ]
  },
  position: 'start:help'
} );

// Register a new menu bar menu.
editor.ui.extendMenuBar( {
  menu: {
    menuId: 'customMenu',
    label: 'customMenu',
    groups: [
      {
        groupId: 'customGroup',
        items: [
          'menuBar:customFunctionButton'
        ]
      }
    ]
  },
  position: 'after:help'
} );

    Parameters

    config : MenuBarConfigAddedItem | MenuBarConfigAddedGroup | MenuBarConfigAddedMenu

    Returns

    void

  • inherited

    fire( eventOrInfo, args ) → GetEventInfo<TEvent>[ 'return' ]

    See source

    Fires an event, executing all callbacks registered for it.

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

    Type parameters

    TEvent : extends BaseEvent

    The type describing the event. See BaseEvent.

    Parameters

    eventOrInfo : GetNameOrEventInfo<TEvent>

    The name of the event or EventInfo object if event is delegated.

    args : TEvent[ 'args' ]

    Additional arguments to be passed to the callbacks.

    Returns

    GetEventInfo<TEvent>[ 'return' ]

    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).

  • inherited

    getEditableElement( rootName ) → undefined | HTMLElement

    See source

    Returns the editable editor element with the given name or null if editable does not exist.

    Parameters

    rootName : string

    The editable name.

    Defaults to 'main'

    Returns

    undefined | HTMLElement

  • inherited

    getEditableElementsNames() → IterableIterator<string>

    See source

    Returns array of names of all editor editable elements.

    Returns

    IterableIterator<string>

  • init() → void

    See source

    Initializes the UI.

    Returns

    void

  • inherited

    listenTo( emitter, event, callback, [ options ] ) → void

    See source

    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

  • inherited

    off( event, callback ) → void

    See source

    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

  • inherited

    on( event, callback, [ options ] ) → void

    See source

    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

  • inherited

    once( event, callback, [ options ] ) → void

    See source

    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

  • inherited

    removeEditableElement( rootName ) → void

    See source

    Removes the editable from the editor UI. Removes all handlers added by setEditableElement.

    Parameters

    rootName : string

    The name of the editable element to remove.

    Returns

    void

  • inherited

    set( values ) → void

    See source

    Creates and sets the value of an observable properties of this object. Such a property becomes a part of the state and is observable.

    It accepts a single object literal containing key/value pairs with properties to be set.

    This method throws the observable-set-cannot-override error if the observable instance already has a property with the given property name. This prevents from mistakenly overriding existing properties and methods, but means that foo.set( 'bar', 1 ) may be slightly slower than foo.bar = 1.

    In TypeScript, those properties should be declared in class using declare keyword. In example:

    public declare myProp1: number;
public declare myProp2: string;

constructor() {
	this.set( {
		'myProp1: 2,
		'myProp2: 'foo'
	} );
}

    Parameters

    values : object

    An object with name=>value pairs.

    Returns

    void

  • inherited

    set( name, value ) → void

    See source

    Creates and sets the value of an observable property of this object. Such a property becomes a part of the state and is observable.

    This method throws the observable-set-cannot-override error if the observable instance already has a property with the given property name. This prevents from mistakenly overriding existing properties and methods, but means that foo.set( 'bar', 1 ) may be slightly slower than foo.bar = 1.

    In TypeScript, those properties should be declared in class using declare keyword. In example:

    public declare myProp: number;

constructor() {
	this.set( 'myProp', 2 );
}

    Type parameters

    K

    Parameters

    name : K

    The property's name.

    value : BalloonEditorUI[ K ]

    The property's value.

    Returns

    void

  • inherited

    setEditableElement( rootName, domElement ) → void

    See source

    Stores the native DOM editable element used by the editor under a unique name.

    Also, registers the element in the editor to maintain the accessibility of the UI. When the user is editing text in a focusable editable area, they can use the Alt + F10 keystroke to navigate over editor toolbars. See addToolbar.

    Parameters

    rootName : string

    The unique name of the editable element.

    domElement : HTMLElement

    The native DOM editable element.

    Returns

    void

  • inherited

    stopDelegating( [ event ], [ emitter ] ) → void

    See source

    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

  • inherited

    stopListening( [ emitter ], [ event ], [ callback ] ) → void

    See source

    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

  • inherited

    unbind( unbindProperties ) → void

    See source

    Removes the binding created with bind.

    // Removes the binding for the 'a' property.
A.unbind( 'a' );

// Removes bindings for all properties.
A.unbind();

    Parameters

    unbindProperties : Array<'off' | 'on' | 'once' | 'listenTo' | 'stopListening' | 'fire' | 'delegate' | 'stopDelegating' | 'set' | 'bind' | 'unbind' | 'decorate' | 'element' | 'view' | 'viewportOffset' | 'destroy' | 'focusTracker' | 'update' | 'poweredBy' | 'init' | 'componentFactory' | 'editor' | 'tooltipManager' | 'ariaLiveAnnouncer' | 'isReady' | 'setEditableElement' | 'removeEditableElement' | 'getEditableElement' | 'getEditableElementsNames' | 'addToolbar' | 'extendMenuBar'>

    Observable properties to be unbound. All the bindings will be released if no properties are provided.

    Returns

    void

  • inherited

    update() → void

    See source

    Fires the update event.

    This method should be called when the editor UI (e.g. positions of its balloons) needs to be updated due to some environmental change which CKEditor 5 is not aware of (e.g. resize of a container in which it is used).

    Returns

    void

  • protected inherited

    _initMenuBar( menuBarView ) → void

    See source

    Initializes menu bar.

    Parameters

    menuBarView : MenuBarView

    Returns

    void

  • private

    _initPlaceholder() → void

    See source

    Enable the placeholder text on the editing root.

    Returns

    void

Events

  • inherited

    change:viewportOffset( eventInfo, name, value = { [value.bottom], [value.left], [value.right], [value.top] }, oldValue = { [oldValue.bottom], [oldValue.left], [oldValue.right], [oldValue.top] } )

    See source

    Fired when the viewportOffset property changed value.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (viewportOffset).

    value : object

    New value of the viewportOffset property with given key or null, if operation should remove property.

    Properties
    [ value.bottom ] : number
    [ value.left ] : number
    [ value.right ] : number
    [ value.top ] : number
    oldValue : object

    Old value of the viewportOffset property with given key or null, if property was not set before.

    Properties
    [ oldValue.bottom ] : number
    [ oldValue.left ] : number
    [ oldValue.right ] : number
    [ oldValue.top ] : number

  • inherited

    change:{property}( eventInfo, name, value, oldValue )

    See source

    Fired when a property changed value.

    observable.set( 'prop', 1 );

observable.on<ObservableChangeEvent<number>>( 'change:prop', ( evt, propertyName, newValue, oldValue ) => {
	console.log( `${ propertyName } has changed from ${ oldValue } to ${ newValue }` );
} );

observable.prop = 2; // -> 'prop has changed from 1 to 2'

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    The property name.

    value : TValue

    The new property value.

    oldValue : TValue

    The previous property value.

  • inherited

    ready( eventInfo )

    See source

    Fired when the editor UI is ready.

    Fired before event-ready.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

  • inherited

    set:viewportOffset( eventInfo, name, value = { [value.bottom], [value.left], [value.right], [value.top] }, oldValue = { [oldValue.bottom], [oldValue.left], [oldValue.right], [oldValue.top] } )

    See source

    Fired when the viewportOffset property is going to be set but is not set yet (before the change event is fired).

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    Name of the changed property (viewportOffset).

    value : object

    New value of the viewportOffset property with given key or null, if operation should remove property.

    Properties
    [ value.bottom ] : number
    [ value.left ] : number
    [ value.right ] : number
    [ value.top ] : number
    oldValue : object

    Old value of the viewportOffset property with given key or null, if property was not set before.

    Properties
    [ oldValue.bottom ] : number
    [ oldValue.left ] : number
    [ oldValue.right ] : number
    [ oldValue.top ] : number

  • inherited

    set:{property}( eventInfo, name, value, oldValue )

    See source

    Fired when a property value is going to be set but is not set yet (before the change event is fired).

    You can control the final value of the property by using the event's return property.

    observable.set( 'prop', 1 );

observable.on<ObservableSetEvent<number>>( 'set:prop', ( evt, propertyName, newValue, oldValue ) => {
	console.log( `Value is going to be changed from ${ oldValue } to ${ newValue }` );
	console.log( `Current property value is ${ observable[ propertyName ] }` );

	// Let's override the value.
	evt.return = 3;
} );

observable.on<ObservableChangeEvent<number>>( 'change:prop', ( evt, propertyName, newValue, oldValue ) => {
	console.log( `Value has changed from ${ oldValue } to ${ newValue }` );
} );

observable.prop = 2; // -> 'Value is going to be changed from 1 to 2'
                     // -> 'Current property value is 1'
                     // -> 'Value has changed from 1 to 3'

    Note: The event is fired even when the new value is the same as the old value.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : string

    The property name.

    value : TValue

    The new property value.

    oldValue : TValue

    The previous property value.

  • inherited

    update( eventInfo )

    See source

    Fired whenever the UI (all related components) should be refreshed.

    Note:: The event is fired after each event-layoutChanged. It can also be fired manually via the update method.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.