CreateUndo(string)

grandMA3 User Manual » Plugins » Lua Functions - Object-Free API » CreateUndo(string)

Version 2.2

Description

The CreateUndo Lua function returns a handle to a list of commands and function calls grouped in the same oops action.

Functions can be executed with a reference to the undo handle. This adds the function to the undo list.

Undo lists need to be closed using the CloseUndo function.

Arguments

String:
A text string must be added. It can be used to identify the undo list.

Return

Handle:
The function returns the handle to the undo list.

Example

This example creates an undo list, performs a series of commands being added to the undo list, and closes the undo list. Now, the series of commands can be oopsed with one oops command.

Copy Code

Lua

return function()
    -- Create the undo group.
    local MyNewUndo = CreateUndo("MySelection")
    -- Make some command line actions linked to the undo.
    Cmd("ClearAll", MyNewUndo)
    Cmd("Fixture 1", MyNewUndo)
    Cmd("Fixture 2", MyNewUndo)
    Cmd("Fixture 5", MyNewUndo)
    Cmd("Fixture 7", MyNewUndo)
    -- Closing the undo group and store it's return in a variable.
    local closeSuccess = CloseUndo(MyNewUndo)
    -- Print the feedback from the closing action - 1 = Success / 0 = Failure.
    if closeSuccess == false then
        ErrPrintf("The CloseUndo was not successful")
    elseif closeSuccess == true then
        Printf("The CloseUndo was successful")
    else
        Printf("The CloseUndo did not return a meaningful result")
    end
end