Model (engine/model)
@ckeditor/ckeditor5-engine/src/model/model
Editor's data model. Read about the model in the engine architecture guide.
Filtering
Properties
-
Model's document.
-
markers : MarkerCollection
readonly
Model's marker collection.
-
Model's schema.
-
_currentWriter : Writer
private
The last created and currently used writer instance.
-
_pendingChanges : Array.<Function>
private
All callbacks added by
change
orenqueueChange
methods waiting to be executed.
Methods
-
applyOperation( operation )
Decorated function for applying operations to the model.
This is a low-level way of changing the model. It is exposed for very specific use cases (like the undo feature). Normally, to modify the model, you will want to use
Writer
. See also Changing the model section of the Editing architecture guide.Parameters
operation : Operation
The operation to apply.
-
bind( bindProperties ) → Object
Binds observable properties to another objects implementing
Observable
interface (likeModel
).Once bound, the observable will immediately share the current state of properties of the observable it is bound to and react to the changes to these properties in the future.
Note: To release the binding use
unbind
.Using
bind().to()
chain:A.bind( 'a' ).to( B ); A.bind( 'a' ).to( B, 'b' ); A.bind( 'a', 'b' ).to( B, 'c', 'd' ); A.bind( 'a' ).to( B, 'b', C, 'd', ( b, d ) => b + d );
It is also possible to bind to the same property in a observables collection using
bind().toMany()
chain:A.bind( 'a' ).toMany( [ B, C, D ], 'x', ( a, b, c ) => a + b + c ); A.bind( 'a' ).toMany( [ B, C, D ], 'x', ( ...x ) => x.every( x => x ) );
Parameters
bindProperties : String
Observable properties that will be bound to another observable(s).
Returns
Object
The bind chain with the
to()
andtoMany()
methods.
-
change( callback ) → *
The
change()
method is the primary way of changing the model. You should use it to modify all document nodes (including detached nodes – i.e. nodes not added to the model document), the document's selection, and model markers.model.change( writer => { writer.insertText( 'foo', paragraph, 'end' ); } );
All changes inside the change block use the same
Batch
so they are combined into a single undo step.model.change( writer => { writer.insertText( 'foo', paragraph, 'end' ); // foo. model.change( writer => { writer.insertText( 'bar', paragraph, 'end' ); // foobar. } ); writer.insertText( 'bom', paragraph, 'end' ); // foobarbom. } );
The callback of the
change()
block is executed synchronously.You can also return a value from the change block.
const img = model.change( writer => { return writer.createElement( 'img' ); } );
Parameters
callback : function
Callback function which may modify the model.
Returns
*
Value returned by the callback.
-
decorate( methodName )
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.
This is a very simplified method decoration. Itself it doesn't change the behavior of a method (expect adding the event), but it allows to modify it later on by listening to the method's event.
For example, in order to cancel the method execution one can stop the event:
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: we used a high priority listener here to execute this callback before the one which calls the original method (which used the default priority).
It's also possible to change the return value:
foo.on( 'method', ( evt ) => { evt.return = 'Foo!'; } ); foo.method(); // -> 'Foo'
Finally, it's possible to access and modify the parameters:
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
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
-
deleteContent( selection, batch, [ options ] = { [options.leaveUnmerged], [options.doNotResetEntireContent] } )
Deletes content of the selection and merge siblings. The resulting selection is always collapsed.
Note: For the sake of predictability, the resulting selection should always be collapsed. In cases where a feature wants to modify deleting behavior so selection isn't collapsed (e.g. a table feature may want to keep row selection after pressing Backspace), then that behavior should be implemented in the view's listener. At the same time, the table feature will need to modify this method's behavior too, e.g. to "delete contents and then collapse the selection inside the last selected cell" or "delete the row and collapse selection somewhere near". That needs to be done in order to ensure that other features which use
deleteContent()
will work well with tables.Parameters
selection : Selection | DocumentSelection
Selection of which the content should be deleted.
batch : Batch
Batch to which the operations will be added.
[ options ] : Object
-
Properties
[ options.leaveUnmerged ] : Boolean
Whether to merge elements after removing the content of the selection.
For example
<heading1>x[x</heading1><paragraph>y]y</paragraph>
will become:<heading1>x^y</heading1>
with the option disabled (leaveUnmerged == false
)<heading1>x^</heading1><paragraph>y</paragraph>
with enabled (leaveUnmerged == true
).
Note: object and limit elements will not be merged.
Defaults to
false
[ options.doNotResetEntireContent ] : Boolean
Whether to skip replacing the entire content with a paragraph when the entire content was selected.
For example
<heading1>[x</heading1><paragraph>y]</paragraph>
will become:<paragraph>^</paragraph>
with the option disabled (doNotResetEntireContent == false
)<heading1>^</heading1>
with enabled (doNotResetEntireContent == true
)
Defaults to
false
Fires
-
destroy()
Removes all events listeners set by model instance and destroys
Document
. -
enqueueChange( batchOrType, callback )
The
enqueueChange()
method performs similar task as thechange()
method, with two major differences.First, the callback of
enqueueChange()
is executed when all other enqueued changes are done. It might be executed immediately if it is not nested in any other change block, but if it is nested in another (enqueue)change block, it will be delayed and executed after the outermost block.model.change( writer => { console.log( 1 ); model.enqueueChange( writer => { console.log( 2 ); } ); console.log( 3 ); } ); // Will log: 1, 3, 2.
Second, it lets you define the
Batch
into which you want to add your changes. By default, a new batch is created. In the sample above,change
andenqueueChange
blocks use a different batch (and differentWriter
since each of them operates on the separate batch).When using the
enqueueChange()
block you can also add some changes to the batch you used before.model.enqueueChange( batch, writer => { writer.insertText( 'foo', paragraph, 'end' ); } );
The batch instance can be obtained from the writer.
Parameters
batchOrType : Batch | 'transparent' | 'default'
Batch or batch type should be used in the callback. If not defined, a new batch will be created.
callback : function
Callback function which may modify the model.
-
fire( eventOrInfo, [ args ] ) → *
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).
-
getSelectedContent( selection ) → DocumentFragment
Gets a clone of the selected content.
For example, for the following selection:
<paragraph>x</paragraph> <blockQuote> <paragraph>y</paragraph> <heading1>fir[st</heading1> </blockQuote> <paragraph>se]cond</paragraph> <paragraph>z</paragraph>
It will return a document fragment with such a content:
<blockQuote> <heading1>st</heading1> </blockQuote> <paragraph>se</paragraph>
Parameters
selection : Selection | DocumentSelection
The selection of which content will be returned.
Returns
Fires
-
hasContent( rangeOrElement ) → Boolean
-
insertContent( content, [ selectable ] )
Inserts content at the position in the editor specified by the selection, as one would expect the paste functionality to work.
This is a high-level method. It takes the schema into consideration when inserting the content, clears the given selection's content before inserting nodes and moves the selection to its target position at the end of the process. It can split elements, merge them, wrap bare text nodes with paragraphs, etc. — just like the pasting feature should do.
For lower-level methods see
Writer
.This method, unlike
Writer
's methods, does not have to be used inside achange()
block.Conversion and schema
Inserting elements and text nodes into the model is not enough to make CKEditor 5 render that content to the user. CKEditor 5 implements a model-view-controller architecture and what
model.insertContent()
does is only adding nodes to the model. Additionally, you need to define converters between the model and view and define those nodes in the schema.So, while this method may seem similar to CKEditor 4
editor.insertHtml()
(in fact, both methods are used for paste-like content insertion), the CKEditor 5 method cannot be use to insert arbitrary HTML unless converters are defined for all elements and attributes in that HTML.Examples
Using
insertContent()
with a manually created model structure:// Let's create a document fragment containing such content as: // // <paragrap>foo</paragraph> // <blockQuote> // <paragraph>bar</paragraph> // </blockQuote> const docFrag = editor.model.change( writer => { const p1 = writer.createElement( 'paragraph' ); const p2 = writer.createElement( 'paragraph' ); const blockQuote = writer.createElement( 'blockQuote' ); const docFrag = writer.createDocumentFragment(); writer.append( p1, docFrag ); writer.append( blockQuote, docFrag ); writer.append( p2, blockQuote ); writer.insertText( 'foo', p1 ); writer.insertText( 'bar', p2 ); return docFrag; } ); // insertContent() does not have to be used in a change() block. It can, though, // so this code could be moved to the callback defined above. editor.model.insertContent( docFrag );
Using
insertContent()
with an HTML string converted to a model document fragment (similar to the pasting mechanism):// You can create your own HtmlDataProcessor instance or use editor.data.processor // if you have not overridden the default one (which is the HtmlDataProcessor instance). const htmlDP = new HtmlDataProcessor(); // Convert an HTML string to a view document fragment: const viewFragment = htmlDP.toView( htmlString ); // Convert the view document fragment to a model document fragment // in the context of $root. This conversion takes the schema into // account so if, for example, the view document fragment contained a bare text node, // this text node cannot be a child of $root, so it will be automatically // wrapped with a <paragraph>. You can define the context yourself (in the second parameter), // and e.g. convert the content like it would happen in a <paragraph>. // Note: The clipboard feature uses a custom context called $clipboardHolder // which has a loosened schema. const modelFragment = editor.data.toModel( viewFragment ); editor.model.insertContent( modelFragment );
By default this method will use the document selection but it can also be used with a position, range or selection instance.
// Insert text at the current document selection position. editor.model.change( writer => { editor.model.insertContent( writer.createText( 'x' ) ); } ); // Insert text at a given position - the document selection will not be modified. editor.model.change( writer => { editor.model.insertContent( writer.createText( 'x' ), Position.createAt( doc.getRoot(), 2 ) ); } );
If an instance of
Selection
is passed asselectable
it will be moved to the target position (where the document selection should be moved after the insertion).// Insert text replacing the given selection instance. const selection = new Selection( paragraph, 'in' ); editor.model.change( writer => { editor.model.insertContent( writer.createText( 'x' ), selection ); // insertContent() modifies the passed selection instance so it can be used to set the document selection. // Note: This is not necessary when you passed the document selection to insertContent(). writer.setSelection( selection ); } );
Parameters
content : DocumentFragment | Item
The content to insert.
[ selectable ] : Selection | DocumentSelection | Position | Element | Iterable.<Range> | Range | null
The selection into which the content should be inserted. If not provided, the current model document selection will be used.
Defaults to
model.document.selection
Fires
-
listenTo( emitter, event, callback, [ options ] = { [options.priority] } )
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
{}
-
modifySelection( selection, [ options ] = { [options.direction], [options.unit] } )
Modifies the selection. Currently, the supported modifications are:
- Extending. The selection focus is moved in the specified
options.direction
with a step specified inoptions.unit
. Possible values forunit
are:'character'
(default) - moves selection by one user-perceived character. In most cases this means moving by one character inString
sense. However, unicode also defines "combing marks". These are special symbols, that combines with a symbol before it ("base character") to create one user-perceived character. For example,q̣̇
is a normal letterq
with two "combining marks": upper dot (Ux0307
) and lower dot (Ux0323
). For most actions, i.e. extending selection by one position, it is correct to include both "base character" and all of it's "combining marks". That is why'character'
value is most natural and common method of modifying selection.'codePoint'
- moves selection by one unicode code point. In contrary to,'character'
unit, this will insert selection between "base character" and "combining mark", because "combining marks" have their own unicode code points. However, for technical reasons, unicode code points with values aboveUxFFFF
are represented in nativeString
by two characters, called "surrogate pairs". Halves of "surrogate pairs" have a meaning only when placed next to each other. For example𨭎
is represented inString
by\uD862\uDF4E
. Both\uD862
and\uDF4E
do not have any meaning outside the pair (are rendered as ? when alone). Position between them would be incorrect. In this case, selection extension will include whole "surrogate pair".'word'
- moves selection by a whole word.
Note: if you extend a forward selection in a backward direction you will in fact shrink it.
Parameters
selection : Selection | DocumentSelection
The selection to modify.
[ options ] : Object
-
Properties
[ options.direction ] : 'forward' | 'backward'
The direction in which the selection should be modified.
Defaults to
'forward'
[ options.unit ] : 'character' | 'codePoint' | 'word'
The unit by which selection should be modified.
Defaults to
'character'
Fires
- Extending. The selection focus is moved in the specified
-
off( event, callback )
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] } )
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] } )
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
{}
-
set( name, [ value ] )
Creates and sets the value of an observable property of this object. Such an property becomes a part of the state and is be 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 have 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).
-
stopDelegating( [ event ], [ emitter ] )
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 ] )
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 ] )
Removes the binding created with
bind
.A.unbind( 'a' ); A.unbind();
Parameters
[ unbindProperties ] : String
Observable properties to be unbound. All the bindings will be released if no properties provided.
-
_runPendingChanges() → Array.<*>
private
Common part of
change
andenqueueChange
which calls callbacks and returns array of values returned by these callbacks.Returns
Array.<*>
Array of values returned by callbacks.
Events
-
_afterChanges( eventInfo )
protected
Fired when leaving the outermost
enqueueChange
orchange
block.Parameters
eventInfo : EventInfo
An object containing information about the fired event.
-
_beforeChanges( eventInfo )
protected
Fired when entering the outermost
enqueueChange
orchange
block.Parameters
eventInfo : EventInfo
An object containing information about the fired event.
-
_change( eventInfo, writer )
protected
Fired after leaving each
enqueueChange
block or outermostchange
block.Note: This is an internal event! Use
event-change
instead.Parameters
-
applyOperation( eventInfo, args )
Fired every time any operation is applied on the model using
applyOperation
.Note that this event is suitable only for very specific use-cases. Use it if you need to listen to every single operation applied on the document. However, in most cases
event-change
should be used.A few callbacks are already added to this event by engine internal classes:
- with
highest
priority operation is validated, - with
normal
priority operation is executed, - with
low
priority theDocument
updates its version, - with
low
priorityLivePosition
andLiveRange
update themselves.
Parameters
- with
-
change:{property}( eventInfo, name, value, oldValue )
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.
-
deleteContent( eventInfo, args )
Event fired when
deleteContent
method is called.The default action of that method is implemented as a listener to this event so it can be fully customized by the features.
Parameters
eventInfo : EventInfo
An object containing information about the fired event.
args : Array
The arguments passed to the original method.
-
getSelectedContent( eventInfo, args )
Event fired when
getSelectedContent
method is called.The default action of that method is implemented as a listener to this event so it can be fully customized by the features.
Parameters
eventInfo : EventInfo
An object containing information about the fired event.
args : Array
The arguments passed to the original method.
-
insertContent( eventInfo, args )
Event fired when
insertContent
method is called.The default action of that method is implemented as a listener to this event so it can be fully customized by the features.
Note The
selectable
parameter for theinsertContent
is optional. Whenundefined
value is passed the method usesmodel.document.selection
.Parameters
eventInfo : EventInfo
An object containing information about the fired event.
args : Array
The arguments passed to the original method.
-
modifySelection( eventInfo, args )
Event fired when
modifySelection
method is called.The default action of that method is implemented as a listener to this event so it can be fully customized by the features.
Parameters
eventInfo : EventInfo
An object containing information about the fired event.
args : Array
The arguments passed to the original method.
-
set:{property}( eventInfo, name, value, oldValue )
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: 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.