I think very much information was stored in the attributes.
Why didn't you use nested elements?
<informatio>
<from>Test06 Test06N</from>
<birthdate>10-01-1960</birthdate>
</informatio>
also you used <information> in two different ways. The second one should be condition or something like that.</information>
<information from='Test06 Test06N' birthdate='10-01-1960'></information> <information email='d@e.f' phone='123123123' strasse='sesame street' plz='1111' ort='the Place'></information> <information positive='no' date_infected='n/a' symptoms_started='n/a' test_date='n/a' test_result='n/a' healthy_again='n/a'></information> What happens when a contact is not assigned to an event? Will it be written as assigned to an event of type "unknown"?
Perhaps it would be better to have the contacts directly as part of the cases and the events separately?
A better description for an XML.
I will create and example in detail.
Slav: Is not needed in XML.
We start from the user=case, then events/contacts can be embbeded. and a unassigned.
Diff:
Example added. if easier you can use JSON (same structure and names)
XML is rewritten following the new format.