DataController (engine/controller)

@ckeditor/ckeditor5-engine/src/controller/datacontroller

class

Controller for the data pipeline. The data pipeline controls how data is retrieved from the document and set inside it. Hence, the controller features two methods which allow to get and set data of the model using the given:

data processor,
downcast converters,
upcast converters.

An instance of the data controller is always available in the editor.data property:

editor.data.get( { rootName: 'customRoot' } ); // -> '<p>Hello!</p>'

Filtering

Public
Inherited
Mixed
Protected
Private
Deprecated

Properties

downcastDispatcher : DowncastDispatcher

readonly

Downcast dispatcher used by the get method. Downcast converters should be attached to it.

See source
htmlProcessor : HtmlDataProcessor

readonly

Data processor used specifically for HTML conversion.

See source
mapper : Mapper

readonly

Mapper used for the conversion. It has no permanent bindings, because these are created while getting data and ae cleared directly after the data are converted. However, the mapper is defined as a class property, because it needs to be passed to the DowncastDispatcher as a conversion API.

See source
model : Model

readonly

Data model.

See source
processor : DataProcessor

Data processor used during the conversion. Same instance as htmlProcessor by default. Can be replaced at run time to handle different format, e.g. XML or Markdown.

See source
stylesProcessor : StylesProcessor

readonly

Styles processor used during the conversion.

See source
upcastDispatcher : UpcastDispatcher

readonly

Upcast dispatcher used by the set method. Upcast converters should be attached to it.

See source
viewDocument : Document

readonly

The view document used by the data controller.

See source
_viewWriter : DowncastWriter

private readonly

The view downcast writer just for data conversion purposes, i.e. to modify the viewDocument.

See source

Methods

constructor( model, stylesProcessor )

Creates a data controller instance.

See source

Parameters

model : Model

Data model.

stylesProcessor : StylesProcessor

The styles processor instance.
addStyleProcessorRules( callback )
Adds the style processor normalization rules.

See source
You can implement your own rules as well as use one of the available processor rules:
- background: addBackgroundRules
- border: addBorderRules
- margin: addMarginRules
- padding: addPaddingRules
Parameters

callback : function
bind( bindProperties ) → Object

mixed
Binds observable properties to other objects implementing the Observable interface.

See source
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 : String

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

Returns

Object

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

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.

See source
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

mixed
Delegates selected events to another Emitter. For instance:

See source
```
emitterA.delegate( 'eventX' ).to( emitterB );
emitterA.delegate( 'eventX', 'eventY' ).to( emitterC );
```
then eventX is delegated (fired by) emitterB and emitterC along with data:
```
emitterA.fire( 'eventX', data );
```
and eventY is delegated (fired by) emitterC along with data:
```
emitterA.fire( 'eventY', data );
```
Parameters

events : String

Event names that will be delegated to another emitter.

Returns

EmitterMixinDelegateChain
destroy()

Removes all event listeners set by the DataController.

See source
fire( eventOrInfo, [ args ] ) → *

mixed

Fires an event, executing all callbacks registered for it.

See source

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

Parameters

eventOrInfo : String | EventInfo

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

[ args ] : *

Additional arguments to be passed to the callbacks.

Returns

*

By default the method returns undefined. However, the return value can be changed by listeners through modification of the evt.return's property (the event info is the first param of every callback).
get( [ options ] = { [options.rootName], [options.trim] } ) → String
Returns the model's data converted by downcast dispatchers attached to downcastDispatcher and formatted by the data processor.

See source
Parameters

[ options ] : Object

Additional configuration for the retrieved data. DataController provides two optional properties: rootName and trim. Other properties of this object are specified by various editor features.

Properties

[ options.rootName ] : String

Root name.

Defaults to 'main'

[ options.trim ] : String

Whether returned data should be trimmed. This option is set to empty by default, which means whenever editor content is considered empty, an empty string will be returned. To turn off trimming completely use 'none'. In such cases the exact content will be returned (for example a <p> </p> for an empty editor).

Defaults to 'empty'

Returns

String

Output data.

Fires
- get
init( data ) → Promise
Sets the initial input data parsed by the data processor and converted by the view-to-model converters. Initial data can be only set to a document whose version is equal 0.

See source
Note This method is decorated which is used by e.g. collaborative editing plugin that syncs remote data on init.

When data is passed as a string, it is initialized on the default main root:
```
dataController.init( '<p>Foo</p>' ); // Initializes data on the `main` root only, as no other is specified.
```
To initialize data on a different root or multiple roots at once, an object containing rootName - data pairs should be passed:
```
dataController.init( { main: '<p>Foo</p>', title: '<h1>Bar</h1>' } ); // Initializes data on both the `main` and `title` roots.
```
Parameters

data : String | Object.<String, String>

Input data as a string or an object containing the rootName - data pairs to initialize data on multiple roots at once.

Returns

Promise

Promise that is resolved after the data is set on the editor.

Fires
- init
listenTo( emitter, event, callback, [ options ] = { [options.priority] } )

mixed
Registers a callback function to be executed when an event is fired in a specific (emitter) object.

See source
Events can be grouped in namespaces using :. When namespaced event is fired, it additionally fires all callbacks for that namespace.
```
// myEmitter.on( ... ) is a shorthand for myEmitter.listenTo( myEmitter, ... ).
myEmitter.on( 'myGroup', genericCallback );
myEmitter.on( 'myGroup:myEvent', specificCallback );

// genericCallback is fired.
myEmitter.fire( 'myGroup' );
// both genericCallback and specificCallback are fired.
myEmitter.fire( 'myGroup:myEvent' );
// genericCallback is fired even though there are no callbacks for "foo".
myEmitter.fire( 'myGroup:foo' );
```
An event callback can stop the event and set the return value of the fire method.

Parameters

emitter : Emitter

The object that fires the event.

event : String

The name of the event.

callback : function

The function to be called on event.

[ options ] : Object

Additional options.

Properties

[ options.priority ] : PriorityString | Number

The priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.

Defaults to 'normal'

Defaults to {}
off( event, callback )

mixed

Stops executing the callback on the given event. Shorthand for this.stopListening( this, event, callback ).

See source

Parameters

event : String

The name of the event.

callback : function

The function to stop being called.
on( event, callback, [ options ] = { [options.priority] } )

mixed

Registers a callback function to be executed when an event is fired.

See source

Shorthand for this.listenTo( this, event, callback, options ) (it makes the emitter listen on itself).

Parameters

event : String

The name of the event.

callback : function

The function to be called on event.

[ options ] : Object

Additional options.

Properties

[ options.priority ] : PriorityString | Number

The priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.

Defaults to 'normal'

Defaults to {}
once( event, callback, [ options ] = { [options.priority] } )

mixed

Registers a callback function to be executed on the next time the event is fired only. This is similar to calling on followed by off in the callback.

See source

Parameters

event : String

The name of the event.

callback : function

The function to be called on event.

[ options ] : Object

Additional options.

Properties

[ options.priority ] : PriorityString | Number

The priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.

Defaults to 'normal'

Defaults to {}
parse( data, [ context ] ) → DocumentFragment
Returns the data parsed by the data processor and then converted by upcast converters attached to the upcastDispatcher.

See source
Parameters

data : String

Data to parse.

[ context ] : SchemaContextDefinition

Base context in which the view will be converted to the model. See: convert.

Defaults to '$root'

Returns

DocumentFragment

Parsed data.

Related:
- DataController#set
registerRawContentMatcher( pattern )

Registers a MatcherPattern on an htmlProcessor and a processor for view elements whose content should be treated as raw data and not processed during the conversion from DOM to view elements.

See source

The raw data can be later accessed by the view element custom property "$rawContent".

Parameters

pattern : MatcherPattern

Pattern matching all view elements whose content should be treated as a raw data.
set( data, [ options ] = { [options.batchType] } )
Sets the input data parsed by the data processor and converted by the view-to-model converters. This method can be used any time to replace existing editor data with the new one without clearing the document history.

See source
This method also creates a batch with all the changes applied. If all you need is to parse data, use the parse method.

When data is passed as a string it is set on the default main root:
```
dataController.set( '<p>Foo</p>' ); // Sets data on the `main` root, as no other is specified.
```
To set data on a different root or multiple roots at once, an object containing rootName - data pairs should be passed:
```
dataController.set( { main: '<p>Foo</p>', title: '<h1>Bar</h1>' } ); // Sets data on the `main` and `title` roots as specified.
```
To set the data with a preserved undo stack and add the change to the undo stack, set { isUndoable: true } as a batchType option.
```
dataController.set( '<p>Foo</p>', { batchType: { isUndoable: true } } );
```
Parameters

data : String | Object.<String, String>

Input data as a string or an object containing the rootName - data pairs to set data on multiple roots at once.

[ options ] : Object

Options for setting data.

Properties

[ options.batchType ] : Object

The batch type that will be used to create a batch for the changes applied by this method. By default, the batch will be set as not undoable and the undo stack will be cleared after the new data is applied (all undo steps will be removed). If the batch type isUndoable flag is be set to true, the undo stack will be preserved instead and not cleared when new data is applied.

Defaults to {}

Fires
- set
stopDelegating( [ event ], [ emitter ] )

mixed
Stops delegating events. It can be used at different levels:

See source
- To stop delegating all events.
- To stop delegating a specific event to all emitters.
- To stop delegating a specific event to a specific emitter.
Parameters

[ event ] : String

The name of the event to stop delegating. If omitted, stops it all delegations.

[ emitter ] : Emitter

(requires event) The object to stop delegating a particular event to. If omitted, stops delegation of event to all emitters.
stopListening( [ emitter ], [ event ], [ callback ] )

mixed
Stops listening for events. It can be used at different levels:

See source
- To stop listening to a specific callback.
- To stop listening to a specific event.
- To stop listening to all events fired by a specific object.
- To stop listening to all events fired by all objects.
Parameters

[ emitter ] : Emitter

The object to stop listening to. If omitted, stops it for all objects.

[ event ] : String

(Requires the emitter) The name of the event to stop listening to. If omitted, stops it for all events from emitter.

[ callback ] : function

(Requires the event) The function to be removed from the call list for the given event.
stringify( modelElementOrFragment, [ options ] ) → String

Returns the content of the given model's element or model document fragment converted by the downcast converters attached to the downcastDispatcher and formatted by the data processor.

See source

Parameters

modelElementOrFragment : Element | DocumentFragment

The element whose content will be stringified.

[ options ] : Object

Additional configuration passed to the conversion process.

Returns

String

Output data.
toModel( viewElementOrFragment, [ context ] ) → DocumentFragment

Returns the result of the given view element or view document fragment converted by the view-to-model converters, wrapped by DocumentFragment.

See source

When marker elements were converted during the conversion process, it will be set as a document fragment's static markers map.

Parameters

viewElementOrFragment : Element | DocumentFragment

The element or document fragment whose content will be converted.

[ context ] : SchemaContextDefinition

Base context in which the view will be converted to the model. See: convert.

Defaults to '$root'

Returns

DocumentFragment

Output document fragment.
toView( modelElementOrFragment, [ options ] ) → DocumentFragment

Returns the content of the given model element or model document fragment converted by the downcast converters attached to downcastDispatcher into a view document fragment.

See source

Parameters

modelElementOrFragment : Element | DocumentFragment

Element or document fragment whose content will be converted.

[ options ] : Object

Additional configuration that will be available through the options during the conversion process.

Defaults to {}

Returns

DocumentFragment

Output view DocumentFragment.
unbind( [ unbindProperties ] )

mixed
Removes the binding created with bind.

See source
```
// 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.
_addEventListener( event, callback, [ options ] = { [options.priority] } )

protected mixed

Adds callback to emitter for given event.

See source

Parameters

event : String

The name of the event.

callback : function

The function to be called on event.

[ options ] : Object

Additional options.

Properties

[ options.priority ] : PriorityString | Number

The priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.

Defaults to 'normal'

Defaults to {}
_removeEventListener( event, callback )

protected mixed

Removes callback from emitter for given event.

See source

Parameters

event : String

The name of the event.

callback : function

The function to stop being called.
_checkIfRootsExists( rootNames ) → Boolean

private

Checks whether all provided root names are actually existing editor roots.

See source

Parameters

rootNames : Array.<String>

Root names to check.

Returns

Boolean

Whether all provided root names are existing editor roots.

Events

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

mixed
Fired when a property changed value.

See source
```
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.
get( eventInfo )

Event fired after the get() method has been run.

See source

The get event is fired by the decorated get method. See decorate for more information and samples.

Parameters

eventInfo : EventInfo

An object containing information about the fired event.
init( eventInfo )

An event fired after the init() method was run. It can be listened to in order to adjust or modify the initialization flow. However, if the init event is stopped or prevented, the ready event should be fired manually.

See source

The init event is fired by the decorated init method. See decorate for more information and samples.

Parameters

eventInfo : EventInfo

An object containing information about the fired event.
ready( eventInfo )

Event fired once the data initialization has finished.

See source

Parameters

eventInfo : EventInfo

An object containing information about the fired event.
set( eventInfo )

An event fired after set() method has been run.

See source

The set event is fired by the decorated set method. See decorate for more information and samples.

Parameters

eventInfo : EventInfo

An object containing information about the fired event.
set:{property}( eventInfo, name, value, oldValue )

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

See source
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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DataController (engine/controller)

Filtering

Properties

downcastDispatcher : DowncastDispatchermodule:engine/controller/datacontroller~DataController#downcastDispatcher

htmlProcessor : HtmlDataProcessormodule:engine/controller/datacontroller~DataController#htmlProcessor

mapper : Mappermodule:engine/controller/datacontroller~DataController#mapper

model : Modelmodule:engine/controller/datacontroller~DataController#model

processor : DataProcessormodule:engine/controller/datacontroller~DataController#processor

stylesProcessor : StylesProcessormodule:engine/controller/datacontroller~DataController#stylesProcessor

upcastDispatcher : UpcastDispatchermodule:engine/controller/datacontroller~DataController#upcastDispatcher

viewDocument : Documentmodule:engine/controller/datacontroller~DataController#viewDocument

_viewWriter : DowncastWritermodule:engine/controller/datacontroller~DataController#_viewWriter

Methods

constructor( model, stylesProcessor )module:engine/controller/datacontroller~DataController#constructor

Parameters

addStyleProcessorRules( callback )module:engine/controller/datacontroller~DataController#addStyleProcessorRules

Parameters

bind( bindProperties ) → Objectmodule:engine/controller/datacontroller~DataController#bind

Parameters

Returns

decorate( methodName )module:engine/controller/datacontroller~DataController#decorate

Parameters

delegate( events ) → EmitterMixinDelegateChainmodule:engine/controller/datacontroller~DataController#delegate

Parameters

Returns

destroy()module:engine/controller/datacontroller~DataController#destroy

fire( eventOrInfo, [ args ] ) → *module:engine/controller/datacontroller~DataController#fire

Parameters

Returns

get( [ options ] = { [options.rootName], [options.trim] } ) → Stringmodule:engine/controller/datacontroller~DataController#get

Parameters

Returns

Fires

init( data ) → Promisemodule:engine/controller/datacontroller~DataController#init

Parameters

Returns

Fires

listenTo( emitter, event, callback, [ options ] = { [options.priority] } )module:engine/controller/datacontroller~DataController#listenTo

Parameters

off( event, callback )module:engine/controller/datacontroller~DataController#off

Parameters

on( event, callback, [ options ] = { [options.priority] } )module:engine/controller/datacontroller~DataController#on

Parameters

once( event, callback, [ options ] = { [options.priority] } )module:engine/controller/datacontroller~DataController#once

Parameters

parse( data, [ context ] ) → DocumentFragmentmodule:engine/controller/datacontroller~DataController#parse

Parameters

Returns

Related:

registerRawContentMatcher( pattern )module:engine/controller/datacontroller~DataController#registerRawContentMatcher

Parameters

set( data, [ options ] = { [options.batchType] } )module:engine/controller/datacontroller~DataController#set

Parameters

Fires

stopDelegating( [ event ], [ emitter ] )module:engine/controller/datacontroller~DataController#stopDelegating

Parameters

stopListening( [ emitter ], [ event ], [ callback ] )module:engine/controller/datacontroller~DataController#stopListening

Parameters

stringify( modelElementOrFragment, [ options ] ) → Stringmodule:engine/controller/datacontroller~DataController#stringify

Parameters

Returns

toModel( viewElementOrFragment, [ context ] ) → DocumentFragmentmodule:engine/controller/datacontroller~DataController#toModel

Parameters

Returns

toView( modelElementOrFragment, [ options ] ) → DocumentFragmentmodule:engine/controller/datacontroller~DataController#toView

Parameters

Returns

unbind( [ unbindProperties ] )module:engine/controller/datacontroller~DataController#unbind

Parameters

_addEventListener( event, callback, [ options ] = { [options.priority] } )module:engine/controller/datacontroller~DataController#_addEventListener

Parameters

_removeEventListener( event, callback )module:engine/controller/datacontroller~DataController#_removeEventListener

Parameters

_checkIfRootsExists( rootNames ) → Booleanmodule:engine/controller/datacontroller~DataController#_checkIfRootsExists

Parameters

Returns

Events

change:{property}( eventInfo, name, value, oldValue )module:engine/controller/datacontroller~DataController#event:change:{property}

Parameters

get( eventInfo )module:engine/controller/datacontroller~DataController#event:get

`downcastDispatcher : DowncastDispatcher`

`htmlProcessor : HtmlDataProcessor`

`mapper : Mapper`

`model : Model`

`processor : DataProcessor`

`stylesProcessor : StylesProcessor`

`upcastDispatcher : UpcastDispatcher`

`viewDocument : Document`

`_viewWriter : DowncastWriter`

`constructor( model, stylesProcessor )`

`addStyleProcessorRules( callback )`

`bind( bindProperties ) → Object`

`decorate( methodName )`

`delegate( events ) → EmitterMixinDelegateChain`

`destroy()`

`fire( eventOrInfo, [ args ] ) → *`

`get( [ options ] = { [options.rootName], [options.trim] } ) → String`

`init( data ) → Promise`

`listenTo( emitter, event, callback, [ options ] = { [options.priority] } )`

`off( event, callback )`

`on( event, callback, [ options ] = { [options.priority] } )`

`once( event, callback, [ options ] = { [options.priority] } )`

`parse( data, [ context ] ) → DocumentFragment`

`registerRawContentMatcher( pattern )`

`set( data, [ options ] = { [options.batchType] } )`

`stopDelegating( [ event ], [ emitter ] )`

`stopListening( [ emitter ], [ event ], [ callback ] )`

`stringify( modelElementOrFragment, [ options ] ) → String`

`toModel( viewElementOrFragment, [ context ] ) → DocumentFragment`

`toView( modelElementOrFragment, [ options ] ) → DocumentFragment`

`unbind( [ unbindProperties ] )`

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

`_removeEventListener( event, callback )`

`_checkIfRootsExists( rootNames ) → Boolean`

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

`get( eventInfo )`

`init( eventInfo )`

`ready( eventInfo )`

`set( eventInfo )`

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