I'm looking for a simple, clean way of displaying a 'percentage complete

Pretty interesting use case. These are the two ideas that I can think of. The quick and dirty way is to convert the CDT into TEXT and then count the number of "=," which is there when a value of the CDT is null and use this as the total number of empty elements. Evaluate this against the total number of elements in the CDT and you should get the number. You can count the number of "=" to do this dynamically as well - just in case the CDT structure changes. Note: I am assuming all elements are required in your use case. The second (and probably a more reliable way) is to use TOXML() to convert the CDT into XML and use expression to find out number of empty nodes.

Pretty interesting use case. These are the two ideas that I can think of. The quick and dirty way is to convert the CDT into TEXT and then count the number of "=," which is there when a value of the CDT is null and use this as the total number of empty elements. Evaluate this against the total number of elements in the CDT and you should get the number. You can count the number of "=" to do this dynamically as well - just in case the CDT structure changes. Note: I am assuming all elements are required in your use case. The second (and probably a more reliable way) is to use TOXML() to convert the CDT into XML and use expression to find out number of empty nodes.