Creates a new Command instance.
The editor on which this command will be used.
Protected_A flag indicating whether a command's isEnabled state should be changed depending on where the document
selection is placed.
By default, it is set to true. If the document selection is placed in a
module:engine/model/model~Model#canEditAt non-editable place (such as non-editable root), the command becomes disabled.
The flag should be changed to false in a concrete command's constructor if the command should not change its isEnabled
accordingly to the document selection.
ReadonlyeditorThe editor on which this command will be used.
ReadonlyisFlag indicating whether a command is enabled or disabled. A disabled command will do nothing when executed.
A given command class should control this value by overriding the #refresh refresh() method.
It is possible to disable a command "from outside" using #forceDisabled method.
ReadonlyvalueThe value of the command. A given command class should define what it represents for it.
For example, the 'bold' command's value indicates whether the selection starts in a bolded text.
And the value of the 'link' command may be an object with link details.
It is possible for a command to have no value (e.g. for stateless actions such as 'uploadImage').
A given command class should control this value by overriding the #refresh refresh() method.
A flag indicating whether a command execution changes the editor data or not.
Commands with affectsData set to false will not be automatically disabled in
the module:core/editor/editor~Editor#isReadOnly read-only mode and
{@glink features/read-only#related-features other editor modes} with restricted user write permissions.
Note: You do not have to set it for your every command. It is true by default.
Binds #set observable properties to other objects implementing the module:utils/observablemixin~Observable interface.
Read more in the {@glink framework/deep-dive/observables#property-bindings 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,command.isEnabled changes, button.isEnabled will immediately reflect its value.Note: To release the binding, use module:utils/observablemixin~Observable#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 );
Observable property that will be bound to other observable(s).
The bind chain with the to() and toMany() methods.
Binds #set observable properties to other objects implementing the module:utils/observablemixin~Observable interface.
Read more in the {@glink framework/deep-dive/observables#property-bindings 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,command.isEnabled changes, button.isEnabled will immediately reflect its value.Note: To release the binding, use module:utils/observablemixin~Observable#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 );
The bind chain with the to() and toMany() methods.
Binds #set observable properties to other objects implementing the module:utils/observablemixin~Observable interface.
Read more in the {@glink framework/deep-dive/observables#property-bindings 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,command.isEnabled changes, button.isEnabled will immediately reflect its value.Note: To release the binding, use module:utils/observablemixin~Observable#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 );
Observable properties that will be bound to other observable(s).
The bind chain with the to() and toMany() methods.
Clears forced disable previously set through #forceDisabled. See #forceDisabled.
Unique identifier, equal to the one passed in #forceDisabled call.
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 {@glink framework/deep-dive/observables#decorating-object-methods 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 module:utils/eventinfo~EventInfo#stop 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 module:utils/priorities~PriorityString 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'
Name of the method to decorate.
Delegates selected events to another module:utils/emittermixin~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 );
Event names that will be delegated to another emitter.
Destroys the command.
Executes the command.
A command may accept parameters. They will be passed from module:core/editor/editor~Editor#execute editor.execute()
to the command.
The execute() method will automatically abort when the command is disabled (#isEnabled is false).
This behavior is implemented by a high priority listener to the #event:execute event.
In order to see how to disable a command from "outside" see the #isEnabled documentation.
This method may return a value, which would be forwarded all the way down to the
module:core/editor/editor~Editor#execute editor.execute().
Fires an event, executing all callbacks registered for it.
The first parameter passed to callbacks is an module:utils/eventinfo~EventInfo object,
followed by the optional args provided in the fire() method call.
The type describing the event. See module:utils/emittermixin~BaseEvent.
The name of the event or EventInfo object if event is delegated.
Additional arguments to be passed to the callbacks.
By default the method returns undefined. However, the return value can be changed by listeners
through modification of the module:utils/eventinfo~EventInfo#return evt.return's property (the event info
is the first param of every callback).
Disables the command.
Command may be disabled by multiple features or algorithms (at once). When disabling a command, unique id should be passed (e.g. the feature name). The same identifier should be used when #clearForceDisabled enabling back the command. The command becomes enabled only after all features #clearForceDisabled enabled it back.
Disabling and enabling a command:
command.isEnabled; // -> true
command.forceDisabled( 'MyFeature' );
command.isEnabled; // -> false
command.clearForceDisabled( 'MyFeature' );
command.isEnabled; // -> true
Command disabled by multiple features:
command.forceDisabled( 'MyFeature' );
command.forceDisabled( 'OtherFeature' );
command.clearForceDisabled( 'MyFeature' );
command.isEnabled; // -> false
command.clearForceDisabled( 'OtherFeature' );
command.isEnabled; // -> true
Multiple disabling with the same identifier is redundant:
command.forceDisabled( 'MyFeature' );
command.forceDisabled( 'MyFeature' );
command.clearForceDisabled( 'MyFeature' );
command.isEnabled; // -> true
Note: some commands or algorithms may have more complex logic when it comes to enabling or disabling certain commands, so the command might be still disabled after #clearForceDisabled was used.
Unique identifier for disabling. Use the same id when #clearForceDisabled enabling back the command.
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 module:utils/eventinfo~EventInfo#stop stop the event and set the module:utils/eventinfo~EventInfo#return return value of the #fire method.
The type describing the event. See module:utils/emittermixin~BaseEvent.
The object that fires the event.
The name of the event.
The function to be called on event.
Optionaloptions: GetCallbackOptions<TEvent>Additional options.
Stops executing the callback on the given event.
Shorthand for #stopListening this.stopListening( this, event, callback ).
The name of the event.
The function to stop being called.
Registers a callback function to be executed when an event is fired.
Shorthand for #listenTo this.listenTo( this, event, callback, options ) (it makes the emitter
listen on itself).
The type descibing the event. See module:utils/emittermixin~BaseEvent.
The name of the event.
The function to be called on event.
Optionaloptions: GetCallbackOptions<TEvent>Additional options.
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.
The type descibing the event. See module:utils/emittermixin~BaseEvent.
The name of the event.
The function to be called on event.
Optionaloptions: GetCallbackOptions<TEvent>Additional options.
Refreshes the command. The command should update its #isEnabled and #value properties in this method.
This method is automatically called when module:engine/model/document~ModelDocument#event:change any changes are applied to the document.
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 );
}
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'
} );
}
An object with name=>value pairs.
OptionalaffectsData?: unknownOptionalbind?: unknownOptionalclearForceDisabled?: unknownOptionaldecorate?: unknownOptionaldelegate?: unknownOptionaldestroy?: unknownOptional Readonlyeditor?: unknownThe editor on which this command will be used.
Optionalexecute?: unknownOptionalfire?: unknownOptionalforceDisabled?: unknownOptional ReadonlyisEnabled?: unknownFlag indicating whether a command is enabled or disabled. A disabled command will do nothing when executed.
A given command class should control this value by overriding the #refresh refresh() method.
It is possible to disable a command "from outside" using #forceDisabled method.
OptionallistenTo?: unknownOptionaloff?: unknownOptionalon?: unknownOptionalonce?: unknownOptionalrefresh?: unknownOptionalset?: unknownOptionalstopDelegating?: unknownOptionalstopListening?: unknownOptionalunbind?: unknownOptional Readonlyvalue?: unknownThe value of the command. A given command class should define what it represents for it.
For example, the 'bold' command's value indicates whether the selection starts in a bolded text.
And the value of the 'link' command may be an object with link details.
It is possible for a command to have no value (e.g. for stateless actions such as 'uploadImage').
A given command class should control this value by overriding the #refresh refresh() method.
Stops delegating events. It can be used at different levels:
Optionalevent: stringThe name of the event to stop delegating. If omitted, stops it all delegations.
Optionalemitter: Emitter(requires event) The object to stop delegating a particular event to.
If omitted, stops delegation of event to all emitters.
Stops listening for events. It can be used at different levels:
Optionalemitter: EmitterThe object to stop listening to. If omitted, stops it for all objects.
Optionalevent: string(Requires the emitter) The name of the event to stop listening to. If omitted, stops it
for all events from emitter.
Optionalcallback: Function(Requires the event) The function to be removed from the call list for the given
event.
Removes the binding created with #bind.
// Removes the binding for the 'a' property.
A.unbind( 'a' );
// Removes bindings for all properties.
A.unbind();
Observable properties to be unbound. All the bindings will be released if no properties are provided.
Base class for the CKEditor commands.
Commands are the main way to manipulate the editor contents and state. They are mostly used by UI elements (or by other commands) to make changes in the model. Commands are available in every part of the code that has access to the module:core/editor/editor~Editor editor instance.
Instances of registered commands can be retrieved from module:core/editor/editor~Editor#commands
editor.commands. The easiest way to execute a command is through module:core/editor/editor~Editor#executeeditor.execute().By default, commands are disabled when the editor is in the module:core/editor/editor~Editor#isReadOnly read-only mode but commands with the module:core/command~Command#affectsData
affectsDataflag set tofalsewill not be disabled.