@lexical/history

Interfaces

HistoryConfig

Defined in: packages/lexical-history/src/index.ts:622

Properties

createInitialHistoryState

createInitialHistoryState: (editor) => HistoryState

Defined in: packages/lexical-history/src/index.ts:631

The initial history state, the default is createEmptyHistoryState.

Parameters

editor

LexicalEditor

Returns

HistoryState

delay

delay: number

Defined in: packages/lexical-history/src/index.ts:627

The time (in milliseconds) the editor should delay generating a new history stack, instead of merging the current changes with the current stack. The default is 300ms.

disabled

disabled: boolean

Defined in: packages/lexical-history/src/index.ts:635

Whether history is disabled or not

maxDepth

maxDepth: number | null

Defined in: packages/lexical-history/src/index.ts:651

The maximum number of entries the undo stack may hold. When the cap is exceeded the oldest entries are dropped (FIFO) so the stack stays at this length. Defaults to null, which keeps the stack unbounded — the historical behavior. Setting a finite cap is recommended for editors that may receive a very large number of distinct history events (long writing sessions, automated input, etc.) since each entry retains a full EditorState snapshot.

For reference, ProseMirror's history() plugin defaults to depth: 100.

now

now: () => number

Defined in: packages/lexical-history/src/index.ts:639

The now() function, defaults to Date.now.

Returns

number

---

HistoryExtensionOutput

Defined in: packages/lexical-history/src/index.ts:670

The output signals exposed by HistoryExtension.

Config-derived signals (delay, disabled, historyState, maxDepth, now) are writable so that peer extensions such as SharedHistoryExtension can redirect them at runtime. The canUndo / canRedo signals are readonly for consumers — they are derived from the current HistoryState and kept in sync automatically.

Properties

canRedo

canRedo: ReadonlySignal<boolean>

Defined in: packages/lexical-history/src/index.ts:675

true when there is at least one entry in the redo stack, i.e. the editor can perform a redo.

canUndo

canUndo: ReadonlySignal<boolean>

Defined in: packages/lexical-history/src/index.ts:680

true when there is at least one entry in the undo stack, i.e. the editor can perform an undo.

delay

delay: Signal<number>

Defined in: packages/lexical-history/src/index.ts:682

The merge-delay in milliseconds forwarded to registerHistory.

disabled

disabled: Signal<boolean>

Defined in: packages/lexical-history/src/index.ts:684

When true the history listener is not registered.

historyState

historyState: Signal<HistoryState>

Defined in: packages/lexical-history/src/index.ts:686

The active HistoryState instance.

maxDepth

maxDepth: Signal<number | null>

Defined in: packages/lexical-history/src/index.ts:692

Maximum number of entries the undo stack may hold. null disables the cap. Changes apply to the next history event — the current undo stack is not retroactively trimmed when the value is lowered.

now

now: Signal<() => number>

Defined in: packages/lexical-history/src/index.ts:694

The clock function forwarded to registerHistory.

---

SharedHistoryConfig

Defined in: packages/lexical-history/src/index.ts:775

Properties

disabled

disabled: boolean

Defined in: packages/lexical-history/src/index.ts:779

Whether shared history is disabled or not

parentEditor

parentEditor: LexicalEditor | null

Defined in: packages/lexical-history/src/index.ts:785

The parentEditor to use, by default it is derived from config.parentEditor which can be provided by NestedEditorExtension

Type Aliases

HistoryState

HistoryState = object

Defined in: packages/lexical-history/src/index.ts:69

The undo/redo history maintained by the history plugin: the current entry plus the undoStack and redoStack of previous and future HistoryStateEntrys. Create an empty one with createEmptyHistoryState and pass it to the history plugin to share history across editors.

Properties

current

current: null | HistoryStateEntry

Defined in: packages/lexical-history/src/index.ts:70

redoStack

redoStack: HistoryStateEntry[]

Defined in: packages/lexical-history/src/index.ts:71

undoStack

undoStack: HistoryStateEntry[]

Defined in: packages/lexical-history/src/index.ts:72

---

HistoryStateEntry

HistoryStateEntry = object

Defined in: packages/lexical-history/src/index.ts:58

Properties

editor

editor: LexicalEditor

Defined in: packages/lexical-history/src/index.ts:59

editorState

editorState: EditorState

Defined in: packages/lexical-history/src/index.ts:60

Variables

HistoryExtension

const HistoryExtension: LexicalExtension<HistoryConfig, "@lexical/history/History", HistoryExtensionOutput, HistoryExtensionInit>

Defined in: packages/lexical-history/src/index.ts:701

Registers necessary listeners to manage undo/redo history stack and related editor commands, via the @lexical/history module.

---

SharedHistoryExtension

const SharedHistoryExtension: LexicalExtension<SharedHistoryConfig, "@lexical/history/SharedHistory", NamedSignalsOutput<{ disabled: boolean; parentEditor: LexicalEditor | null; }>, unknown>

Defined in: packages/lexical-history/src/index.ts:793

Registers necessary listeners to manage undo/redo history stack and related editor commands, via the @lexical/history module, only if the parent editor has a history plugin implementation.

Functions

createEmptyHistoryState()

createEmptyHistoryState(): HistoryState

Defined in: packages/lexical-history/src/index.ts:614

Creates an empty history state.

Returns

HistoryState

• The empty history state, as an object.

---

registerHistory()

registerHistory(editor, historyState, delay, dateNow?, onHistoryStateChange?, maxDepth?): () => void

Defined in: packages/lexical-history/src/index.ts:484

Registers necessary listeners to manage undo/redo history stack and related editor commands. It returns unregister callback that cleans up all listeners and should be called on editor unmount.

Parameters

editor

LexicalEditor

The lexical editor.

historyState

HistoryState

The history state, containing the current state and the undo/redo stack.

delay

number | ReadonlySignal<number>

The time (in milliseconds) the editor should delay generating a new history stack, instead of merging the current changes with the current stack.

dateNow?

() => number

The clock function used for delay-based merging.

onHistoryStateChange?

(state) => void

Optional callback invoked once on registration and again any time historyState is mutated (push, pop, clear, etc.). It is NOT invoked when a candidate update is discarded without changing the stacks. Useful for keeping derived values (e.g. signals) in sync with the current HistoryState.

maxDepth?

number | ReadonlySignal<number | null> | null

The maximum number of entries the undo stack may hold. When the cap is exceeded a new history event has been pushed the oldest entries are dropped from the front of the stack until the stack length is maxDepth. Pass null (the default) to keep the stack unbounded — the historical behavior. May be a plain number or a ReadonlySignal<number | null> for reactive reconfiguration.

Returns

The listeners cleanup callback function.

() => void