SMART datagrid v.1 > Classes > GridBase
If undoable is true, when there is at least one updated cell which can be reverted from the updating or appending row, or the data set connected to the grid is enabled to run Redo, it will return true.
If Undo stack of grid or data set is changed, onUndoStateChanged event will be fired, and you can also know whether undo/redo is enabled through this event.
Please refer to Undoing Overview for more descriptions about Undo/Redo implementation of SMART datagrid.
document.getElementById('btnUndo').disabled = !grid.canUndo();
document.getElementById('btnRedo').disabled = !grid.canRedo();
$("#btnUndo").click = function () {
grid.canUndo() && grid.undo();
});