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Class

History (engine/model)

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

class
See source

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

Filtering

Properties

  • lastOperation : Operation | undefined

    readonly

    The last history operation.

    See source

  • version : Number

    The version of the last operation in the history.

    See source

    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.

  • _baseVersionToOperationIndex : Map.<Number, Number>

    private

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

    See source

  • _gaps : Map.<number, number>

    private

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

    See source

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

  • _operations : Array.<Operation>

    private readonly

    Operations added to the history.

    See source

  • _undoPairs : Map

    private

    Holds an information which operation undoes which operation.

    See source

    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".

  • _undoneOperations : Set.<Operation>

    private

    Holds all undone operations.

    See source

  • _version : Number

    private

    The history version.

    See source

Methods

  • constructor()

    Creates an empty History instance.

    See source

  • addOperation( operation )

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

    See source

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

    Parameters

    operation : Operation

    Operation to add.

  • getOperation( baseVersion ) → Operation | undefined

    Returns operation from the history that bases on given baseVersion.

    See source

    Parameters

    baseVersion : Number

    Base version of the operation to get.

    Returns

    Operation | undefined

    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.

    See source

    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).

    Returns

    Array.<Operation>

    History operations for the given range, in chronological order.

  • getUndoneOperation( undoingOperation ) → Operation | undefined

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

    See source

    Parameters

    undoingOperation : Operation

    Returns

    Operation | undefined

    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.

    See source

    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.

    See source

    Parameters

    operation : Operation

    Operation to check.

    Returns

    Boolean

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

  • reset()

    Resets the history of operations.

    See source

  • setOperationAsUndone( undoneOperation, undoingOperation )

    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.

    See source

    Parameters

    undoneOperation : Operation

    Operation which is undone by undoingOperation.

    undoingOperation : Operation

    Operation which undoes undoneOperation.