Often there is the need to make sure that an AudienceStream string attribute is not empty. E.g., an action should only be triggered if the string is assigned and its value is not empty.
The rule condition definitions do not help to solve this problem. They only state that "is empty" and "is not empty" apply to attributes imported from iQ.
For strings that contain email addresses the answer is quite simple, one can use the rule "contains @". But what about strings that do not have a common character?
Thank you and kind regards!
@pafe For Visitor and Visit level Strings, they are either "Assigned" (meaning the String is present and has a value) or "Not Assigned" (meaning they don't exist in the Visitor Profile). Empty Strings are not persisted in the Visitor Profile.
For Event Level Strings in Server UDH, it's slightly different. You already know about Strings from iQ (where you have the "empty" rules as well as the "assigned" ones). But for Event level strings declared inside the Server UDH, they are "Assigned" if you pass in a value to that String, even "". Otherwise they are "Not Assigned".