how can I convert an xml to cdt... and I want to use it directly in a rule... ..

Can you explain why this statement is a concern for your use case? "The result of this function is not automatically saved into the process variable " this is mentioned in the documentation just for users not to think that the data is directly saved, this warning is just a reminder that if you want to store the output to a variable you have to do it the same way you do it with other expressions: using a custom output or node input mapped to a variable.

Can you explain why this statement is a concern for your use case? "The result of this function is not automatically saved into the process variable " this is mentioned in the documentation just for users not to think that the data is directly saved, this warning is just a reminder that if you want to store the output to a variable you have to do it the same way you do it with other expressions: using a custom output or node input mapped to a variable.