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getUndoContext

getUndoContext()

(Since HALion 6.1)

Description

Function to check if the current script execution is part of an undo or redo operation.

Available in: Controller.

Return Values

The function returns

• 1 if the changes come from an undo operation,
• 2 if the changes come from a redo operation,
• nil if the changes do not come from an undo or redo operation.

Enumerators

You can use the following enumerators to identify the Undo Context Types.

Example

-- Do nothing if the change callback is executed as part of an undo or redo operation.

function onP1Changed()
  if getUndoContext() then
    return -- do nothing
  end

  -- The following code is only executed if it is not part of an undo or redo operation.
  local oldName = this.name
  local newName = "Some Name "..p1
  startUndoBlock("Name of '"..oldName.."' set to '"..newName.."'")
    this:setName(newName)
  endUndoBlock()
end
  
defineParameter("p1", onP1Changed)

See also: startUndoBlock, endUndoBlock, Undo Context Types