API Reference > imodeljs-frontend > IModelConnection > BriefcaseTxns > onBeforeUndoRedo onBeforeUndoRedo Readonly onBeforeUndoRedo: BeEvent<(isUndo: boolean) => void> = ... Event raised before an undo/redo operation is performed. see BriefcaseTxns.onAfterUndoRedo for the event raised after the operation. Defined in core/frontend/src/BriefcaseTxns.ts Line 82 Last Updated: 11 June, 2024