Allow only particular changes in ur-program

Hi,

I’ve created an urcap; with this cap a user can add a node with some functionality to the ur-program and do some other configurations related to this node.

A python-daemon is controlling a device that sets the userrole via Dashboard. The user “programmer” should be allowed to do any program-changes, but the user “operator” should only be allowed to do changes in the node of the urcap.

For that reason I save the program-file *.urp before the changes to another location and compare the xml-structure to the xml-structure of the changed file, after the program is changed. I also use python-daemon to compare these two xml-files, but that is a very difficult thing to do. If i find a change in the ur-program that is not allowed I overwrite the new program.

I wonder if there is a better way to compare two xml-files and recognize a not allowed change in the program or check particular changes in the program.

Hope someone can help.
Robert