undo - Methods - Question Editor API

Question Editor API Methods


Revert Question Editor state to a previously captured state.

Conditions that may prevent operation to be performed:

  • A previous Undo/Redo operation is still running.
  • There are no previous snapshots to revert to.
  • A snapshot is currently being saved.
  • The page has not yet completely loaded.

To know when the undo operation has completed, listen to the revisionHistoryState:change (refer to event types) and watch for when either canUndo or canRedo is true.


// event to listen - after modifying any input field
questionEditorApp.on("revisionHistoryState:change", function (data) {
    console.log(data); //{canUndo: true, canRedo: false}

questionEditorApp.undo(); //{canUndo: false, canRedo: true}



Return value

Type boolean

If the operation can not be performed, then false is returned

Type null

If the operation can be performed, then null is returned
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