Home/CKEditor 5/API

TextWatcher (typing)

@ckeditor/ckeditor5-typing/src/textwatcher

class

See source

The text watcher feature.

Fires the matched:data, matched:selection and unmatched events on typing or selection changes.

Filtering

Public
Inherited
Internal
Protected
Private
Deprecated

Properties

readonly
hasMatch : boolean

See source
Flag indicating whether there is a match currently.
isEnabled : boolean
See source
Flag indicating whether the TextWatcher instance is enabled or disabled. A disabled TextWatcher will not evaluate text.

To disable TextWatcher:
```
const watcher = new TextWatcher( editor.model, testCallback );

// After this a testCallback will not be called.
watcher.isEnabled = false;
```
readonly
model : Model

See source
The editor's model.
testCallback : ( string ) => unknown
See source
The function used to match the text.

The test callback can return 3 values:
- false if there is no match,
- true if there is a match,
- an object if there is a match and we want to pass some additional information to the event-matched:data event.
private
_hasMatch : boolean

See source
Whether there is a match currently.

Methods

constructor( model, testCallback )

See source
Creates a text watcher instance.

Parameters

model : Model

testCallback : ( string ) => unknown

See testCallback.
inherited
bind( bindProperty1, bindProperty2 ) → DualBindChain<K1, TextWatcher[ K1 ], K2, TextWatcher[ 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, TextWatcher[ K1 ], K2, TextWatcher[ 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' | 'isEnabled' | 'model' | 'testCallback' | 'hasMatch'>

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, TextWatcher[ 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, TextWatcher[ 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' | 'isEnabled' | 'model' | 'testCallback' | 'hasMatch'

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
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
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
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 : TextWatcher[ K ]

The property's value.

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' | 'isEnabled' | 'model' | 'testCallback' | 'hasMatch'>

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

Returns

void
private
_evaluateTextBeforeSelection( suffix, data = { [data.batch] } ) → void
See source
Checks the editor content for matched text.

Parameters

suffix : 'data' | 'selection'

A suffix used for generating the event name.

data : object

Data object for event.

Properties

[ data.batch ] : Batch

Defaults to {}

Returns

void

Fires
private
_startListening() → void

See source
Starts listening to the editor for typing and selection events.

Returns

void

Events

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.
matched:data( eventInfo, data )

See source
Fired whenever the text watcher found a match for data changes.

Parameters

eventInfo : EventInfo

An object containing information about the fired event.

data : object

Event data.
matched:selection( eventInfo, data )

See source
Fired whenever the text watcher found a match for selection changes.

Parameters

eventInfo : EventInfo

An object containing information about the fired event.

data : object

Event data.
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.
unmatched( eventInfo )

See source
Fired whenever the text does not match anymore. Fired only when the text watcher found a match.

Parameters

eventInfo : EventInfo

An object containing information about the fired event.

Every day, we work hard to keep our documentation complete. Have you spotted outdated information? Is something missing? Please report it via our issue tracker.

With the release of version 42.0.0, we have rewritten much of our documentation to reflect the new import paths and features. We appreciate your feedback to help us ensure its accuracy and completeness.

TextWatcher (typing)

Filtering

Properties

readonly hasMatch : booleanmodule:typing/textwatcher~TextWatcher#hasMatch

isEnabled : booleanmodule:typing/textwatcher~TextWatcher#isEnabled

readonly model : Modelmodule:typing/textwatcher~TextWatcher#model

testCallback : ( string ) => unknownmodule:typing/textwatcher~TextWatcher#testCallback

private _hasMatch : booleanmodule:typing/textwatcher~TextWatcher#_hasMatch

Methods

constructor( model, testCallback )module:typing/textwatcher~TextWatcher#constructor

Parameters

inherited bind( bindProperty1, bindProperty2 ) → DualBindChain<K1, TextWatcher[ K1 ], K2, TextWatcher[ K2 ]>module:typing/textwatcher~TextWatcher#bind:DUAL_BIND

Type parameters

Parameters

Returns

inherited bind( bindProperties ) → MultiBindChainmodule:typing/textwatcher~TextWatcher#bind:MANY_BIND

Parameters

Returns

inherited bind( bindProperty ) → SingleBindChain<K, TextWatcher[ K ]>module:typing/textwatcher~TextWatcher#bind:SINGLE_BIND

Type parameters

Parameters

Returns

inherited decorate( methodName ) → voidmodule:typing/textwatcher~TextWatcher#decorate

Parameters

Returns

inherited delegate( events ) → EmitterMixinDelegateChainmodule:typing/textwatcher~TextWatcher#delegate

Parameters

Returns

inherited fire( eventOrInfo, args ) → GetEventInfo<TEvent>[ 'return' ]module:typing/textwatcher~TextWatcher#fire

Type parameters

Parameters

Returns

inherited listenTo( emitter, event, callback, [ options ] ) → voidmodule:typing/textwatcher~TextWatcher#listenTo:BASE_EMITTER

Type parameters

Parameters

Returns

inherited off( event, callback ) → voidmodule:typing/textwatcher~TextWatcher#off

Parameters

Returns

inherited on( event, callback, [ options ] ) → voidmodule:typing/textwatcher~TextWatcher#on

Type parameters

Parameters

Returns

inherited once( event, callback, [ options ] ) → voidmodule:typing/textwatcher~TextWatcher#once

Type parameters

Parameters

Returns

inherited set( values ) → voidmodule:typing/textwatcher~TextWatcher#set:OBJECT

Parameters

Returns

inherited set( name, value ) → voidmodule:typing/textwatcher~TextWatcher#set:KEY_VALUE

Type parameters

Parameters

Returns

inherited stopDelegating( [ event ], [ emitter ] ) → voidmodule:typing/textwatcher~TextWatcher#stopDelegating

Parameters

Returns

inherited stopListening( [ emitter ], [ event ], [ callback ] ) → voidmodule:typing/textwatcher~TextWatcher#stopListening:BASE_STOP

Parameters

Returns

inherited unbind( unbindProperties ) → voidmodule:typing/textwatcher~TextWatcher#unbind

Parameters

Returns

private _evaluateTextBeforeSelection( suffix, data = { [data.batch] } ) → voidmodule:typing/textwatcher~TextWatcher#_evaluateTextBeforeSelection

Parameters

Returns

Fires

private _startListening() → voidmodule:typing/textwatcher~TextWatcher#_startListening

Returns

Events

inherited change:{property}( eventInfo, name, value, oldValue )module:typing/textwatcher~TextWatcher#event:change:{property}

Parameters

matched:data( eventInfo, data )module:typing/textwatcher~TextWatcher#event:matched:data

Parameters

matched:selection( eventInfo, data )module:typing/textwatcher~TextWatcher#event:matched:selection

Parameters

inherited set:{property}( eventInfo, name, value, oldValue )module:typing/textwatcher~TextWatcher#event:set:{property}

Parameters

unmatched( eventInfo )module:typing/textwatcher~TextWatcher#event:unmatched

Parameters

readonly
`hasMatch : boolean`

`isEnabled : boolean`

readonly
`model : Model`

`testCallback : ( string ) => unknown`

private
`_hasMatch : boolean`

`constructor( model, testCallback )`

inherited
`bind( bindProperty1, bindProperty2 ) → DualBindChain<K1, TextWatcher[ K1 ], K2, TextWatcher[ K2 ]>`

inherited
`bind( bindProperties ) → MultiBindChain`

inherited
`bind( bindProperty ) → SingleBindChain<K, TextWatcher[ K ]>`

inherited
`decorate( methodName ) → void`

inherited
`delegate( events ) → EmitterMixinDelegateChain`

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

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

inherited
`off( event, callback ) → void`

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

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

inherited
`set( values ) → void`

inherited
`set( name, value ) → void`

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

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

inherited
`unbind( unbindProperties ) → void`

private
`_evaluateTextBeforeSelection( suffix, data = { [data.batch] } ) → void`

private
`_startListening() → void`

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

`matched:data( eventInfo, data )`

`matched:selection( eventInfo, data )`

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

`unmatched( eventInfo )`