[BUG] ARX refuses to load a project containing a possibly empty string value as QID without hierarchy

[jenno-verdonck]

Describe the bug
In the GUI I have a dataset where a certain Quasi-identifier can also have an empty string as value. I didn't set a hierarchy yet as I didn't want to generalize this value while still taking it into account for k-anonymity. I can perfectly anonymize the data with these settings. I saved the project file and later reloaded it. Suddenly I can't load the file and get the following error: hierarchy does not contain a transformation rule for value ''.
After running the source in debug I could already identify 1 difference. It seems that the default empty hierarchy (only containing the unique values without extra levels) that is given to the anonymizer does contain the empty string as a possibility while the hierarchy that is loaded from the project file does not contain this empty string. The code then crashes on the // Register at the dictionary and encode line in the DataManager constructor.

To Reproduce
Steps to reproduce the behavior:

1. Create an anonymization setup where the input data has a Quasi-identifier with empty values.
2. Do not create a hierarchy for this Quasi-identifier.
3. Anonymize the data.
4. Save the project.
5. Try to load the project from the file
6. See the given error

Expected behavior
It should be possible to load/save this type of project.

ARX GUI (please complete the following information):

• OS: Windows
• Version 3.9.1

[HaRRy-19]

I am still facing this same issue. It doesn't load the complete project if we cannot form a hierarchy since it contains only one value pertaining to that hierarchy. This means that I cannot perform any operation with this tool unless I create another new project from the scratch. Again if you close the tool, and reopen it boils down to the same issue. This workaround is cumbersome. Can this be fixed?

[prasser]

Thanks for reporting this again and sorry that it is not fixed, yet. Just to be sure: in your case it is also a quasi-identifier that contains an empty string as value that causes this?

[HaRRy-19]

Thank you for asking. In my case, if I don't create a hierarchy for a certain row(since it has only one and the same value), I am encountering this issue after I exit the application and open again.

[prasser]

Ok. Are you able to share the file or create a minimal example that can be used to reproduce the issue? If there is no empty value in your case, the issue is likely another issue.

[HaRRy-19]

Sorry in my case as well, it is due to the empty values for certain number of rows.