History

The History interface manages undo and redo functionality for a container that holds some editable content. It emits events when actions like save, undo, or redo are performed.

Note

The constructor is not directly accessible. Instead, you can access its properties and methods via the editor.history object.

Example:

editor.history.save();

Instance properties

list Read only

A list in which the current and previous contents are stored.

• Type: An Array object that contains Nodes objects.

Example:

const list = editor.history.list;

index

A number that always indicates the position at which new content is stored.

• Type: number

Example:

const index = editor.history.index;

limit

The maximum length of the history. Once this limit is reached, the earliest item in the list will be removed.

• Type: number

Example:

editor.history.limit = 100;

contentRules

A ContentRules object defining the HTML parsing rules used by HTMLParser.

• Type: ContentRules

Example:

editor.history.contentRules = {
  h1: {},
  p: {},
};

event Read only

An EventEmitter object used to set up events. For more details, see the Instance events.

• Type: EventEmitter

Example:

editor.history.event.on('save', value => {
  console.log(value);
});

canUndo Read only

A boolean value indicating whether the history can be undone.

• Type: boolean

Example:

const canUndo = editor.history.canUndo;

canRedo Read only

A boolean value indicating whether the history can be redone.

• Type: boolean

Example:

const canRedo = editor.history.canRedo;

Instance methods

undo()

Undoes to the previous saved content.

• Parameters:

  None.

• Return value:

  None.

Example:

editor.history.undo();

redo()

Redoes to the next saved content.

• Parameters:

  None.

• Return value:

  None.

Example:

editor.history.redo();

continue()

Resumes the ability to save history. This method re-enables saving after the pause method has been called.

• Parameters:

  None.

• Return value:

  None.

Example:

editor.history.continue();

pause()

Pauses the ability to save history. This method temporarily disables saving history, which can be resumed later by calling the continue method.

• Parameters:

  None.

• Return value:

  None.

Example:

editor.history.pause();

save()

Saves the current content to the history. The content is saved only if it is different from the previous content.

• Parameters:

  options Optional

  An optional object with the following properties:

  • inputType Optional

    Specifies the action that triggered the save.

    Type: string

  • update Optional

    Specifies whether the current content should update the last item in the history. Defaults to false.

    Type: boolean

  • emitEvent Optional

    Specifies whether to emit the save event. Defaults to true.

    Type: boolean

• Return value:

  None.

Example:

// Adds new item.
editor.history.save();

// Updates the last item.
editor.history.save({
  update: true,
});

Instance events

undo

Fired when the history is undone.

Example:

editor.history.event.on('undo', value => {
  console.log(value);
});

redo

Fired when the history is redone.

Example:

editor.history.event.on('redo', value => {
  console.log(value);
});

save

Fired when the history is saved. The options argument is the options passed to the save method.

Example:

editor.history.event.on('save', (value, options) => {
  console.log(value, options);
});