There are times when you want to validate that the value of a property isn’t blank. For example, you could be checking the output value (published data) of an activity to make sure it’s not blank before proceeding. However, in the list of available comparisons, there isn’t a selection for “Is Null” or “Is Blank”.
So how can you check for blank values?
Use the “Matches Pattern” or “Does Not Match pattern” condition and enter the regular expression
which is interpreted as “blank”.