Class

History (engine/model)

@ckeditor/ckeditor5-engine/src/model/history

class

History keeps the track of all the operations applied to the document.

Filtering

Properties

  • readonly

    lastOperation : undefined | Operation

    The last history operation.

  • version : number

    The version of the last operation in the history.

    The history version is incremented automatically when a new operation is added to the history. Setting the version manually should be done only in rare circumstances when a gap is planned between history versions. When doing so, a gap will be created and the history will accept adding an operation with base version equal to the new history version.

    Parameters

    version : number
  • private

    _baseVersionToOperationIndex : Map<number, number>

    A map that allows retrieving the operations fast based on the given base version.

  • private

    _gaps : Map<number, number>

    The gap pairs kept in the <from,to> format.

    Anytime the history.version is set to a version larger than history.version + 1, a new <lastHistoryVersion, newHistoryVersion> entry is added to the map.

  • private

    _operations : Array<Operation>

    Operations added to the history.

  • private

    _undoPairs : Map<Operation, Operation>

    Holds an information which operation undoes which operation.

    Keys of the map are "undoing operations", that is operations that undone some other operations. For each key, the value is an operation that has been undone by the "undoing operation".

  • private

    _undoneOperations : Set<Operation>

    Holds all undone operations.

  • private

    _version : number

    The history version.

Methods

  • addOperation( operation ) → void

    Adds an operation to the history and increments the history version.

    The operation's base version should be equal to the history version. Otherwise an error is thrown.

    Parameters

    operation : Operation

    Returns

    void
  • getOperation( baseVersion ) → undefined | Operation

    Returns operation from the history that bases on given baseVersion.

    Parameters

    baseVersion : number

    Base version of the operation to get.

    Returns

    undefined | Operation

    Operation with given base version or undefined if there is no such operation in history.

  • getOperations( [ fromBaseVersion ], toBaseVersion ) → Array<Operation>

    Returns operations from the given range of operation base versions that were added to the history.

    Note that there may be gaps in operations base versions.

    Parameters

    [ fromBaseVersion ] : number

    Base version from which operations should be returned (inclusive).

    toBaseVersion : number

    Base version up to which operations should be returned (exclusive). *

    Defaults to ...

    Returns

    Array<Operation>

    History operations for the given range, in chronological order.

  • getUndoneOperation( undoingOperation ) → undefined | Operation

    For given undoingOperation, returns the operation which has been undone by it.

    Parameters

    undoingOperation : Operation

    Returns

    undefined | Operation

    Operation that has been undone by given undoingOperation or undefined if given undoingOperation is not undoing any other operation.

  • isUndoingOperation( operation ) → boolean

    Checks whether given operation is undoing any other operation.

    Parameters

    operation : Operation

    Operation to check.

    Returns

    boolean

    true if given operation is undoing any other operation, false otherwise.

  • isUndoneOperation( operation ) → boolean

    Checks whether given operation has been undone by any other operation.

    Parameters

    operation : Operation

    Operation to check.

    Returns

    boolean

    true if given operation has been undone any other operation, false otherwise.

  • reset() → void

    Resets the history of operations.

    Returns

    void
  • setOperationAsUndone( undoneOperation, undoingOperation ) → void

    Marks in history that one operation is an operation that is undoing the other operation. By marking operation this way, history is keeping more context information about operations, which helps in operational transformation.

    Parameters

    undoneOperation : Operation

    Operation which is undone by undoingOperation.

    undoingOperation : Operation

    Operation which undoes undoneOperation.

    Returns

    void