Undo & redo

Every reversible operation records its forward and inverse operations in HistoryService (default limit 500 entries). Undo/redo is built in:

const workbook = editor.workbook;

workbook.undo();
workbook.redo();
workbook.canUndo;
workbook.canRedo;

How it works

• One logical action = one undo entry. Composite mutations are batched.
• beginUpdate() / endUpdate() on the workbook collapse a group of mutations into a single aggregated workbook.update operation and one history entry.
• Replay never re-records. Undo/redo apply the stored inverse/forward operations directly.
• History is transformed. When rows/columns are inserted or deleted, stored entries are shifted so a later undo doesn't clobber the wrong coordinates. Exclusion markers keep structural ops from double-transforming themselves.
• Formula-aware. Undoing a paste or fill restores translated formulas; structural undo replays reference translation.

Observing history

Undo and redo emit marker operations through the operation event stream, so UI can update:

workbook.onOperation((op) => {
  if (op.type === 'undo') console.log('undid', op);
  if (op.type === 'redo') console.log('redid', op);
});

What is undoable

Cell edits, style/format/note/editor changes, merges, structural inserts/deletes/moves, sorting, clipboard paste, fill, conditional formats and validations, chart/pivot/media changes — anything emitted as a reversible operation.

Serialization note

Workbook.fromJSON starts with a clean history — snapshots do not carry undo state.