Class

ImageResizeCommand (image/imageresize)

@ckeditor/ckeditor5-image/src/imageresize/imageresizecommand

class

The image resize command. Currently, it only supports the width attribute.

Filtering

Properties

  • editor : Editor

    readonly inherited

    The editor on which this command will be used.

  • isEnabled : Boolean

    readonly inherited observable

    Flag indicating whether a command is enabled or disabled. A disabled command will do nothing when executed.

    A concrete command class should control this value by overriding the refresh() method.

    It is possible to disable a command from "outside". For instance, in your integration you may want to disable a certain set of commands for the time being. To do that, you can use the fact that isEnabled is observable and it fires the set:isEnabled event every time anyone tries to modify its value:

    function disableCommand( cmd ) {
    	cmd.on( 'set:isEnabled', forceDisable, { priority: 'highest' } );
    
    	cmd.isEnabled = false;
    
    	// Make it possible to enable the command again.
    	return () => {
    		cmd.off( 'set:isEnabled', forceDisable );
    		cmd.refresh();
    	};
    
    	function forceDisable( evt ) {
    		evt.return = false;
    		evt.stop();
    	}
    }
    
    // Usage:
    
    // Disabling the command.
    const enableBold = disableCommand( editor.commands.get( 'bold' ) );
    
    // Enabling the command again.
    enableBold();
  • value

    readonly inherited observable

    The value of the command. A concrete 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 links details.

    It is possible for a command to have no value (e.g. for stateless actions such as 'imageUpload').

    A concrete command class should control this value by overriding the refresh() method.

  • _disableStack : Set.<String>

    private inherited

    Holds identifiers for forceDisabled mechanism.

Methods

  • constructor( editor )

    inherited

    Creates a new Command instance.

    Parameters

    editor : Editor

    Editor on which this command will be used.

  • bind( bindProperties ) → Object

    mixed

    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 : String

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

    Returns

    Object

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

  • clearForceDisabled( id )

    inherited

    Clears forced disable previously set through forceDisabled. See forceDisabled.

    Parameters

    id : String

    Unique identifier, equal to the one passed in forceDisabled call.

  • 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.

    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:

    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()

    inherited

    Destroys the command.

  • execute()

    inherited

    Executes the command.

    A command may accept parameters. They will be passed from 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 editor.execute().

    Fires

  • fire( eventOrInfo, [ args ] ) → *

    mixed

    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.

    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).

  • forceDisabled( id )

    inherited

    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. feature name). The same identifier should be used when enabling back the command. The command becomes enabled only after all features 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.

    Parameters

    id : String

    Unique identifier for disabling. Use the same id when enabling back the command.

  • 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.

    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 ).

    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.

    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.

    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 {}

  • refresh()

    inherited

    Refreshes the command. The command should update its isEnabled and value properties in this method.

    This method is automatically called when any changes are applied to the document.

  • set( name, [ value ] )

    mixed

    Creates and sets the value of an observable property of this object. Such a property becomes a part of the state and is 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 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.

    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 ] )

    mixed

    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.

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

    mixed

    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.

  • unbind( [ unbindProperties ] )

    mixed

    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 ] : String

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

Events

  • change:isEnabled( eventInfo, name, value, oldValue )

    inherited

    Fired when the isEnabled property changed value.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : String

    Name of the changed property (isEnabled).

    value : Boolean

    New value of the isEnabled property with given key or null, if operation should remove property.

    oldValue : Boolean

    Old value of the isEnabled property with given key or null, if property was not set before.

  • change:value( eventInfo, name, value, oldValue )

    inherited

    Fired when the value property changed value.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    name : String

    Name of the changed property (value).

    value : *

    New value of the value property with given key or null, if operation should remove property.

    oldValue : *

    Old value of the value property with given key or null, if property was not set before.

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

    mixed

    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.

  • execute( eventInfo )

    inherited

    Event fired by the execute method. The command action is a listener to this event so it's possible to change/cancel the behavior of the command by listening to this event.

    See decorate for more information and samples.

    Note: This event is fired even if command is disabled. However, it is automatically blocked by a high priority listener in order to prevent command execution.

    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).

    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.