How to create a node with properties in external files

[cinhcet]

actually, this reminds me of this topic:

Ctrl-z undo question

Hi, How does one handle a node, when the user hits ctrl-z? Is there a function with something like "oneditundo"? My current problem is that my node gets in a bad state, if it is configured, and then undo-ed afterwards with ctrl-z.

where also not a good solution for the undo problem was found