ContextualBalloon (ui/panel/balloon)
@ckeditor/ckeditor5-ui/src/panel/balloon/contextualballoon
Provides the common contextual balloon for the editor.
The role of this plugin is to unify the contextual balloons logic, simplify views management and help
avoid the unnecessary complexity of handling multiple BalloonPanelView
instances in the editor.
This plugin allows for creating single or multiple panel stacks.
Each stack may have multiple views, with the one on the top being visible. When the visible view is removed from the stack, the previous view becomes visible.
It might be useful to implement nested navigation in a balloon. For instance, a toolbar view may contain a link button. When you click it, a link view (which lets you set the URL) is created and put on top of the toolbar view, so the link panel is displayed. When you finish editing the link and close (remove) the link view, the toolbar view is visible again.
However, there are cases when there are multiple independent balloons to be displayed, for instance, if the selection is inside two inline comments at the same time. For such cases, you can create two independent panel stacks. The contextual balloon plugin will create a navigation bar to let the users switch between these panel stacks using the "Next" and "Previous" buttons.
If there are no views in the current stack, the balloon panel will try to switch to the next stack. If there are no panels in any stack, the balloon panel will be hidden.
Note: To force the balloon panel to show only one view, even if there are other stacks, use the singleViewMode=true
option
when adding a view to a panel.
From the implementation point of view, the contextual ballon plugin is reusing a single
BalloonPanelView
instance to display multiple contextual balloon
panels in the editor. It also creates a special rotator view,
used to manage multiple panel stacks. Rotator view is a child of the balloon panel view and the parent of the specific
view you want to display. If there is more than one panel stack to be displayed, the rotator view will add a
navigation bar. If there is only one stack, the rotator view is transparent (it does not add any UI elements).
Filtering
Properties
-
editor : Editor
module:ui/panel/balloon/contextualballoon~ContextualBalloon#editor
readonly inherited
The editor instance.
Note that most editors implement the
EditorWithUI
interface in addition to the baseEditor
interface. However, editors with an external UI (i.e. Bootstrap-based) or a headless editor may not implement theEditorWithUI
interface.Because of above, to make plugins more universal, it is recommended to split features into:
- The "editing" part that only uses the
Editor
interface. - The "UI" part that uses both the
Editor
interface and theEditorWithUI
interface.
- The "editing" part that only uses the
-
isEnabled : Boolean
module:ui/panel/balloon/contextualballoon~ContextualBalloon#isEnabled
readonly inherited observable
Flag indicating whether a plugin is enabled or disabled. A disabled plugin will not transform text.
Plugin can be simply disabled like that:
// Disable the plugin so that no toolbars are visible. editor.plugins.get( 'TextTransformation' ).isEnabled = false;
You can also use
forceDisabled
method. -
positionLimiter : Options#limiter
module:ui/panel/balloon/contextualballoon~ContextualBalloon#positionLimiter
The position limiter for the balloon, used when no
limiter
has been passed intoadd
orupdatePosition
.By default, a function that obtains the farthest DOM
RootEditableElement
of theselection
. -
view : BalloonPanelView
module:ui/panel/balloon/contextualballoon~ContextualBalloon#view
readonly
The common balloon panel view.
-
visibleView : View | null
module:ui/panel/balloon/contextualballoon~ContextualBalloon#visibleView
readonly observable
The currently visible view or
null
when there are no views in any stack. -
_disableStack : Set.<String>
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_disableStack
private inherited
Holds identifiers for
forceDisabled
mechanism. -
_fakePanelsView : View
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_fakePanelsView
private
Displays fake panels under the balloon panel view when multiple stacks are added to the balloon.
-
_idToStack : Map.<String, Set>
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_idToStack
private
The map of IDs and stacks.
-
_numberOfStacks : Number
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_numberOfStacks
private readonly observable
A total number of all stacks in the balloon.
-
_rotatorView : RotatorView
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_rotatorView
private
Rotator view embedded in the contextual balloon. Displays the currently visible view in the balloon and provides navigation for switching stacks.
-
_singleViewMode : Boolean
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_singleViewMode
private readonly observable
A flag that controls the single view mode.
-
_viewToStack : Map.<View, Set>
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_viewToStack
private
The map of views and their stacks.
-
_visibleStack : Set
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_visibleStack
private
Returns the stack of the currently visible view.
Static properties
-
isContextPlugin : Boolean
module:ui/panel/balloon/contextualballoon~ContextualBalloon.isContextPlugin
readonly inherited static
A flag which defines if a plugin is allowed or not allowed to be used directly by a
Context
. -
pluginName : String | undefined
module:ui/panel/balloon/contextualballoon~ContextualBalloon.pluginName
readonly inherited static
An optional name of the plugin. If set, the plugin will be available in
get
by its name and its constructor. If not, then only by its constructor.The name should reflect the constructor name.
To keep the plugin class definition tight, it is recommended to define this property as a static getter:
export default class ImageCaption { static get pluginName() { return 'ImageCaption'; } }
Note: The native
Function.name
property could not be used to keep the plugin name because it will be mangled during code minification.Naming a plugin is necessary to enable removing it through the
config.removePlugins
option. -
requires : Array.<Function> | undefined
module:ui/panel/balloon/contextualballoon~ContextualBalloon.requires
readonly inherited static
An array of plugins required by this plugin.
To keep the plugin class definition tight it is recommended to define this property as a static getter:
import Image from './image.js'; export default class ImageCaption { static get requires() { return [ Image ]; } }
Methods
-
constructor( editor )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#constructor
inherited
Creates a new plugin instance. This is the first step of the plugin initialization. See also
init
andafterInit
.A plugin is always instantiated after its dependencies and the
init
andafterInit
methods are called in the same order.Usually, you will want to put your plugin's initialization code in the
init
method. The constructor can be understood as "before init" and used in special cases, just likeafterInit
serves the special "after init" scenarios (e.g.the code which depends on other plugins, but which does not explicitly require them).Parameters
editor : Editor
-
add( data = { [data.stackId], [data.view], [data.position], [data.balloonClassName], [data.withArrow], [data.singleViewMode] } )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#add
Adds a new view to the stack and makes it visible if the current stack is visible or it is the first view in the balloon.
Parameters
data : Object
The configuration of the view.
Properties[ data.stackId ] : String
The ID of the stack that the view is added to.
Defaults to
'main'
[ data.view ] : View
The content of the balloon.
[ data.position ] : Options
Positioning options.
[ data.balloonClassName ] : String
An additional CSS class added to the balloon when visible.
[ data.withArrow ] : Boolean
Whether the balloon should be rendered with an arrow.
Defaults to
true
[ data.singleViewMode ] : Boolean
Whether the view should be the only visible view even if other stacks were added.
Defaults to
false
-
afterInit() → null | Promise
module:ui/panel/balloon/contextualballoon~ContextualBalloon#afterInit
inherited
The third (and last) stage of the plugin initialization. See also
constructor
andinit
.Note: This method is optional. A plugin instance does not need to have it defined.
Returns
null | Promise
-
bind( bindProperties ) → Object
module:ui/panel/balloon/contextualballoon~ContextualBalloon#bind
mixed
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 associatedcommand
(bothObservable
).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 equalscommand.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 (alsoObservables
) 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 : String
Observable properties that will be bound to other observable(s).
Returns
Object
The bind chain with the
to()
andtoMany()
methods.
-
clearForceDisabled( id )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#clearForceDisabled
inherited
Clears forced disable previously set through
forceDisabled
. SeeforceDisabled
.Parameters
id : String
Unique identifier, equal to the one passed in
forceDisabled
call.
-
decorate( methodName )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#decorate
mixed
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 { constructor() { 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 : String
Name of the method to decorate.
-
delegate( events ) → EmitterMixinDelegateChain
module:ui/panel/balloon/contextualballoon~ContextualBalloon#delegate
mixed
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
andemitterC
along withdata
:emitterA.fire( 'eventX', data );
and
eventY
is delegated (fired by)emitterC
along withdata
:emitterA.fire( 'eventY', data );
Parameters
events : String
Event names that will be delegated to another emitter.
Returns
-
destroy() → null | Promise
module:ui/panel/balloon/contextualballoon~ContextualBalloon#destroy
inherited
Destroys the plugin.
Note: This method is optional. A plugin instance does not need to have it defined.
Returns
null | Promise
-
fire( eventOrInfo, [ args ] ) → *
module:ui/panel/balloon/contextualballoon~ContextualBalloon#fire
mixed
Fires an event, executing all callbacks registered for it.
The first parameter passed to callbacks is an
EventInfo
object, followed by the optionalargs
provided in thefire()
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 theevt.return
's property (the event info is the first param of every callback).
-
forceDisabled( id )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#forceDisabled
inherited
Disables the plugin.
Plugin may be disabled by multiple features or algorithms (at once). When disabling a plugin, unique id should be passed (e.g. feature name). The same identifier should be used when enabling back the plugin. The plugin becomes enabled only after all features enabled it back.
Disabling and enabling a plugin:
plugin.isEnabled; // -> true plugin.forceDisabled( 'MyFeature' ); plugin.isEnabled; // -> false plugin.clearForceDisabled( 'MyFeature' ); plugin.isEnabled; // -> true
Plugin disabled by multiple features:
plugin.forceDisabled( 'MyFeature' ); plugin.forceDisabled( 'OtherFeature' ); plugin.clearForceDisabled( 'MyFeature' ); plugin.isEnabled; // -> false plugin.clearForceDisabled( 'OtherFeature' ); plugin.isEnabled; // -> true
Multiple disabling with the same identifier is redundant:
plugin.forceDisabled( 'MyFeature' ); plugin.forceDisabled( 'MyFeature' ); plugin.clearForceDisabled( 'MyFeature' ); plugin.isEnabled; // -> true
Note: some plugins or algorithms may have more complex logic when it comes to enabling or disabling certain plugins, so the plugin might be still disabled after
clearForceDisabled
was used.Parameters
id : String
Unique identifier for disabling. Use the same id when enabling back the plugin.
-
hasView( view ) → Boolean
module:ui/panel/balloon/contextualballoon~ContextualBalloon#hasView
Returns
true
when the given view is in one of the stacks. Otherwise returnsfalse
. -
init() → null | Promise
module:ui/panel/balloon/contextualballoon~ContextualBalloon#init
inherited
The second stage (after plugin
constructor
) of the plugin initialization. Unlike the plugin constructor this method can be asynchronous.A plugin's
init()
method is called after its dependencies are initialized, so in the same order as the constructors of these plugins.Note: This method is optional. A plugin instance does not need to have it defined.
Returns
null | Promise
-
listenTo( emitter, event, callback, [ options ] = { [options.priority] } )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#listenTo
mixed
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.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 )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#off
mixed
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.
-
on( event, callback, [ options ] = { [options.priority] } )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#on
mixed
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).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] } )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#once
mixed
Registers a callback function to be executed on the next time the event is fired only. This is similar to calling
on
followed byoff
in the callback.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
{}
-
remove( view )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#remove
Removes the given view from the stack. If the removed view was visible, the view preceding it in the stack will become visible instead. When there is no view in the stack, the next stack will be displayed. When there are no more stacks, the balloon will hide.
Parameters
view : View
A view to be removed from the balloon.
-
set( name, [ value ] )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#set
mixed
Creates and sets the value of an observable property of this object. Such a property becomes a part of the state and is observable.
It accepts also 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 thatfoo.set( 'bar', 1 )
may be slightly slower thanfoo.bar = 1
.Parameters
name : String | Object
The property's name or object with
name=>value
pairs.[ value ] : *
The property's value (if
name
was passed in the first parameter).
-
showStack( id )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#showStack
Shows the last view from the stack of a given ID.
Parameters
id : String
-
stopDelegating( [ event ], [ emitter ] )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#stopDelegating
mixed
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 ofevent
to all emitters.
-
stopListening( [ emitter ], [ event ], [ callback ] )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#stopListening
mixed
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 fromemitter
.[ callback ] : function
(Requires the
event
) The function to be removed from the call list for the givenevent
.
-
unbind( [ unbindProperties ] )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#unbind
mixed
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 ] : String
Observable properties to be unbound. All the bindings will be released if no properties are provided.
-
updatePosition( [ position ] )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#updatePosition
Updates the position of the balloon using the position data of the first visible view in the stack. When new position data is given, the position data of the currently visible view will be updated.
Parameters
[ position ] : Options
position options.
-
_addEventListener( event, callback, [ options ] = { [options.priority] } )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_addEventListener
protected mixed
Adds callback to emitter for given event.
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 )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_removeEventListener
protected mixed
Removes callback from emitter for given event.
Parameters
event : String
The name of the event.
callback : function
The function to stop being called.
-
_createFakePanelsView() → View
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_createFakePanelsView
private
Returns
-
_createRotatorView() → RotatorView
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_createRotatorView
private
Creates a rotator view.
Returns
-
_getBalloonPosition() → Options
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_getBalloonPosition
private
Returns position options of the last view in the stack. This keeps the balloon in the same position when the view is changed.
Returns
-
_getStackId( stack ) → String
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_getStackId
private
Returns the ID of the given stack.
Parameters
stack : Set
Returns
String
-
_showNextStack()
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_showNextStack
private
Shows the last view from the next stack.
-
_showPrevStack()
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_showPrevStack
private
Shows the last view from the previous stack.
-
_showView( data = { [data.view], [data.balloonClassName], [data.withArrow] } )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#_showView
private
Sets the view as the content of the balloon and attaches the balloon using position options of the first view.
Parameters
data : Object
Configuration.
Properties
Events
-
change:_numberOfStacks( eventInfo, name, value, oldValue )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#event:change:_numberOfStacks
private
Fired when the
_numberOfStacks
property changed value.Parameters
eventInfo : EventInfo
An object containing information about the fired event.
name : String
Name of the changed property (
_numberOfStacks
).value : Number
New value of the
_numberOfStacks
property with given key ornull
, if operation should remove property.oldValue : Number
Old value of the
_numberOfStacks
property with given key ornull
, if property was not set before.
-
change:_singleViewMode( eventInfo, name, value, oldValue )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#event:change:_singleViewMode
private
Fired when the
_singleViewMode
property changed value.Parameters
eventInfo : EventInfo
An object containing information about the fired event.
name : String
Name of the changed property (
_singleViewMode
).value : Boolean
New value of the
_singleViewMode
property with given key ornull
, if operation should remove property.oldValue : Boolean
Old value of the
_singleViewMode
property with given key ornull
, if property was not set before.
-
change:isEnabled( eventInfo, name, value, oldValue )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#event:change:isEnabled
inherited
Fired when the
isEnabled
property changed value.Parameters
eventInfo : EventInfo
An object containing information about the fired event.
name : String
Name of the changed property (
isEnabled
).value : Boolean
New value of the
isEnabled
property with given key ornull
, if operation should remove property.oldValue : Boolean
Old value of the
isEnabled
property with given key ornull
, if property was not set before.
-
change:visibleView( eventInfo, name, value, oldValue )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#event:change:visibleView
Fired when the
visibleView
property changed value.Parameters
eventInfo : EventInfo
An object containing information about the fired event.
name : String
Name of the changed property (
visibleView
).value : View | null
New value of the
visibleView
property with given key ornull
, if operation should remove property.oldValue : View | null
Old value of the
visibleView
property with given key ornull
, if property was not set before.
-
change:{property}( eventInfo, name, value, oldValue )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#event:change:{property}
mixed
Fired when a property changed value.
observable.set( 'prop', 1 ); observable.on( '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 : *
The new property value.
oldValue : *
The previous property value.
-
set:{property}( eventInfo, name, value, oldValue )
module:ui/panel/balloon/contextualballoon~ContextualBalloon#event:set:{property}
mixed
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( '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( '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 : *
The new property value.
oldValue : *
The previous property value.
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