Power Table Drop Down List with ability to enter new text?

Excellent idea! I went ahead and implemented this, but once I did it, the new value is not displayed on the drop down list (apparently configureEditor is only called when the table is first loaded?). When I try to call the function from onCellEdited with

self.configureEditor(self, colIndex, colName)

or

self.configureEditor()

I get an error message stating that the power table has no such attribute. Are extension functions non-accessible?