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Class

Marker (engine/model)

@ckeditor/ckeditor5-engine/src/model/markercollection

class
See source

Marker is a continuous part of the model (like a range), is named and represents some kind of information about the marked part of the model document. In contrary to nodes, which are building blocks of the model document tree, markers are not stored directly in the document tree but in the model markers' collection. Still, they are document data, by giving additional meaning to the part of a model document between marker start and marker end.

In this sense, markers are similar to adding and converting attributes on nodes. The difference is that attribute is connected with a given node (e.g. a character is bold no matter if it gets moved or content around it changes). Markers on the other hand are continuous ranges and are characterized by their start and end position. This means that any character in the marker is marked by the marker. For example, if a character is moved outside of marker it stops being "special" and the marker is shrunk. Similarly, when a character is moved into the marker from other place in document model, it starts being "special" and the marker is enlarged.

Another upside of markers is that finding marked part of document is fast and easy. Using attributes to mark some nodes and then trying to find that part of document would require traversing whole document tree. Marker gives instant access to the range which it is marking at the moment.

Markers are built from a name and a range.

Range of the marker is updated automatically when document changes, using live range mechanism.

Name is used to group and identify markers. Names have to be unique, but markers can be grouped by using common prefixes, separated with :, for example: user:john or search:3. That's useful in term of creating namespaces for custom elements (e.g. comments, highlights). You can use this prefixes in event-update listeners to listen on changes in a group of markers. For instance: model.markers.on( 'update:user', callback ); will be called whenever any user:* markers changes.

There are two types of markers.

  1. Markers managed directly, without using operations. They are added directly by Writer to the MarkerCollection without any additional mechanism. They can be used as bookmarks or visual markers. They are great for showing results of the find, or select link when the focus is in the input.

  2. Markers managed using operations. These markers are also stored in MarkerCollection but changes in these markers is managed the same way all other changes in the model structure - using operations. Therefore, they are handled in the undo stack and synchronized between clients if the collaboration plugin is enabled. This type of markers is useful for solutions like spell checking or comments.

Both type of them should be added / updated by addMarker and removed by removeMarker methods.

model.change( ( writer ) => {
	const marker = writer.addMarker( name, { range, usingOperation: true } );

	// ...

	writer.removeMarker( marker );
} );

See Writer to find more examples.

Since markers need to track change in the document, for efficiency reasons, it is best to create and keep as little markers as possible and remove them as soon as they are not needed anymore.

Markers can be downcasted and upcasted.

Markers downcast happens on event-addMarker and event-removeMarker events. Use downcast converters or attach a custom converter to mentioned events. For data pipeline, marker should be downcasted to an element. Then, it can be upcasted back to a marker. Again, use upcast converters or attach a custom converter to event-element.

Marker instances are created and destroyed only by MarkerCollection.

Filtering

Properties

  • readonly

    affectsData : boolean

    See source

    A value indicating if the marker changes the data.

  • readonly

    managedUsingOperations : boolean

    See source

    A value indicating if the marker is managed using operations. See marker class description to learn more about marker types. See addMarker.

  • readonly

    name : string

    See source

    Marker's name.

  • internal

    _affectsData : boolean

    See source

    Specifies whether the marker affects the data produced by the data pipeline (is persisted in the editor's data).

  • internal

    _managedUsingOperations : boolean

    See source

    Flag indicates if the marker is managed using operations or not.

  • private

    _liveRange : null | LiveRange

    See source

    Range marked by the marker.

Methods

  • constructor( name, liveRange, managedUsingOperations, affectsData )

    See source

    Creates a marker instance.

    Parameters

    name : string

    Marker name.

    liveRange : LiveRange

    Range marked by the marker.

    managedUsingOperations : boolean

    Specifies whether the marker is managed using operations.

    affectsData : boolean

    Specifies whether the marker affects the data produced by the data pipeline (is persisted in the editor's data).

  • 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

  • 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).

  • getData() → MarkerData

    See source

    Returns the marker data (properties defining the marker).

    Returns

    MarkerData

  • getEnd() → Position

    See source

    Returns current marker end position.

    Returns

    Position

  • getRange() → Range

    See source

    Returns a range that represents the current state of the marker.

    Keep in mind that returned value is a Range, not a LiveRange. This means that it is up-to-date and relevant only until next model document change. Do not store values returned by this method. Instead, store name and get Marker instance from MarkerCollection every time there is a need to read marker properties. This will guarantee that the marker has not been removed and that it's data is up-to-date.

    Returns

    Range

  • getStart() → Position

    See source

    Returns current marker start position.

    Returns

    Position

  • inherited

    is( type ) → this is Element | RootElement

    See source

    Checks whether the object is of type Element or its subclass.

    element.is( 'element' ); // -> true
element.is( 'node' ); // -> true
element.is( 'model:element' ); // -> true
element.is( 'model:node' ); // -> true

element.is( 'view:element' ); // -> false
element.is( 'documentSelection' ); // -> false

    Assuming that the object being checked is an element, you can also check its name:

    element.is( 'element', 'imageBlock' ); // -> true if this is an <imageBlock> element
text.is( 'element', 'imageBlock' ); -> false

    Parameters

    type : 'element' | 'model:element'

    Returns

    this is Element | RootElement

  • inherited

    is( type ) → this is RootElement

    See source

    Checks whether the object is of type RootElement.

    rootElement.is( 'rootElement' ); // -> true
rootElement.is( 'element' ); // -> true
rootElement.is( 'node' ); // -> true
rootElement.is( 'model:rootElement' ); // -> true
rootElement.is( 'model:element' ); // -> true
rootElement.is( 'model:node' ); // -> true

rootElement.is( 'view:element' ); // -> false
rootElement.is( 'documentFragment' ); // -> false

    Assuming that the object being checked is an element, you can also check its name:

    rootElement.is( 'rootElement', '$root' ); // -> same as above

    Parameters

    type : 'rootElement' | 'model:rootElement'

    Returns

    this is RootElement

  • inherited

    is( type ) → this is Text

    See source

    Checks whether the object is of type Text.

    text.is( '$text' ); // -> true
text.is( 'node' ); // -> true
text.is( 'model:$text' ); // -> true
text.is( 'model:node' ); // -> true

text.is( 'view:$text' ); // -> false
text.is( 'documentSelection' ); // -> false

    Note: Until version 20.0.0 this method wasn't accepting '$text' type. The legacy 'text' type is still accepted for backward compatibility.

    Parameters

    type : '$text' | 'model:$text'

    Returns

    this is Text

  • inherited

    is( type ) → this is LiveRange

    See source

    Checks whether the object is of type LiveRange.

    liveRange.is( 'range' ); // -> true
liveRange.is( 'model:range' ); // -> true
liveRange.is( 'liveRange' ); // -> true
liveRange.is( 'model:liveRange' ); // -> true

liveRange.is( 'view:range' ); // -> false
liveRange.is( 'documentSelection' ); // -> false

    Parameters

    type : 'liveRange' | 'model:liveRange'

    Returns

    this is LiveRange

  • inherited

    is( type ) → this is DocumentFragment

    See source

    Checks whether the object is of type DocumentFragment.

    docFrag.is( 'documentFragment' ); // -> true
docFrag.is( 'model:documentFragment' ); // -> true

docFrag.is( 'view:documentFragment' ); // -> false
docFrag.is( 'element' ); // -> false
docFrag.is( 'node' ); // -> false

    Parameters

    type : 'documentFragment' | 'model:documentFragment'

    Returns

    this is DocumentFragment

  • inherited

    is( type ) → this is Range | LiveRange

    See source

    Checks whether the object is of type Range or its subclass.

    range.is( 'range' ); // -> true
range.is( 'model:range' ); // -> true

range.is( 'view:range' ); // -> false
range.is( 'documentSelection' ); // -> false

    Parameters

    type : 'range' | 'model:range'

    Returns

    this is Range | LiveRange

  • inherited

    is( type ) → this is LivePosition

    See source

    Checks whether the object is of type LivePosition.

    livePosition.is( 'position' ); // -> true
livePosition.is( 'model:position' ); // -> true
livePosition.is( 'liveposition' ); // -> true
livePosition.is( 'model:livePosition' ); // -> true

livePosition.is( 'view:position' ); // -> false
livePosition.is( 'documentSelection' ); // -> false

    Parameters

    type : 'livePosition' | 'model:livePosition'

    Returns

    this is LivePosition

  • inherited

    is( type ) → this is Position | LivePosition

    See source

    Checks whether the object is of type Position or its subclass.

    position.is( 'position' ); // -> true
position.is( 'model:position' ); // -> true

position.is( 'view:position' ); // -> false
position.is( 'documentSelection' ); // -> false

    Parameters

    type : 'position' | 'model:position'

    Returns

    this is Position | LivePosition

  • inherited

    is( type ) → this is Selection | DocumentSelection

    See source

    Checks whether the object is of type Selection or DocumentSelection.

    selection.is( 'selection' ); // -> true
selection.is( 'model:selection' ); // -> true

selection.is( 'view:selection' ); // -> false
selection.is( 'range' ); // -> false

    Parameters

    type : 'selection' | 'model:selection'

    Returns

    this is Selection | DocumentSelection

  • inherited

    is( type ) → this is Marker

    See source

    Checks whether the object is of type Marker.

    marker.is( 'marker' ); // -> true
marker.is( 'model:marker' ); // -> true

marker.is( 'view:element' ); // -> false
marker.is( 'documentSelection' ); // -> false

    Parameters

    type : 'marker' | 'model:marker'

    Returns

    this is Marker

  • inherited

    is( type, name ) → boolean

    See source

    Checks whether the object is of type Element or its subclass and has the specified name.

    element.is( 'element', 'imageBlock' ); // -> true if this is an <imageBlock> element
text.is( 'element', 'imageBlock' ); -> false

    Type parameters

    N : extends string

    Parameters

    type : 'element' | 'model:element'
    name : N

    Returns

    boolean

  • inherited

    is( type, name ) → boolean

    See source

    Checks whether the object is of type RootElement and has the specified name.

    rootElement.is( 'rootElement', '$root' );

    Type parameters

    N : extends string

    Parameters

    type : 'rootElement' | 'model:rootElement'
    name : N

    Returns

    boolean

  • inherited

    is( type ) → this is TextProxy

    See source

    Checks whether the object is of type TextProxy.

    textProxy.is( '$textProxy' ); // -> true
textProxy.is( 'model:$textProxy' ); // -> true

textProxy.is( 'view:$textProxy' ); // -> false
textProxy.is( 'range' ); // -> false

    Note: Until version 20.0.0 this method wasn't accepting '$textProxy' type. The legacy 'textProxt' type is still accepted for backward compatibility.

    Parameters

    type : '$textProxy' | 'model:$textProxy'

    Returns

    this is TextProxy

  • inherited

    is( type ) → this is DocumentSelection

    See source

    Checks whether the object is of type DocumentSelection.

    selection.is( 'selection' ); // -> true
selection.is( 'documentSelection' ); // -> true
selection.is( 'model:selection' ); // -> true
selection.is( 'model:documentSelection' ); // -> true

selection.is( 'view:selection' ); // -> false
selection.is( 'element' ); // -> false
selection.is( 'node' ); // -> false

    Parameters

    type : 'documentSelection' | 'model:documentSelection'

    Returns

    this is DocumentSelection

  • inherited

    is( type ) → this is Node | Text | Element | RootElement

    See source

    Checks whether the object is of type Node or its subclass.

    This method is useful when processing model objects that are of unknown type. For example, a function may return a DocumentFragment or a Node that can be either a text node or an element. This method can be used to check what kind of object is returned.

    someObject.is( 'element' ); // -> true if this is an element
someObject.is( 'node' ); // -> true if this is a node (a text node or an element)
someObject.is( 'documentFragment' ); // -> true if this is a document fragment

    Since this method is also available on a range of view objects, you can prefix the type of the object with model: or view: to check, for example, if this is the model's or view's element:

    modelElement.is( 'model:element' ); // -> true
modelElement.is( 'view:element' ); // -> false

    By using this method it is also possible to check a name of an element:

    imageElement.is( 'element', 'imageBlock' ); // -> true
imageElement.is( 'element', 'imageBlock' ); // -> same as above
imageElement.is( 'model:element', 'imageBlock' ); // -> same as above, but more precise

    Parameters

    type : 'node' | 'model:node'

    Returns

    this is Node | Text | Element | RootElement

  • 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

    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

  • internal

    _attachLiveRange( liveRange ) → LiveRange

    See source

    Binds new live range to the marker and detach the old one if is attached.

    Parameters

    liveRange : LiveRange

    Live range to attach

    Returns

    LiveRange

    Attached live range.

  • internal

    _detachLiveRange() → void

    See source

    Unbinds and destroys currently attached live range.

    Returns

    void

Events