ESQL : Check One of the incoming xml tag contains serialzed data

Question

Need help to validate if one of the incoming XML tag contains serialized data or not. If ir doesn't contain then have to thow an user defined exception. This has to be achieved using ESQL.

example :

<input_data>
<source>ABCD</source>
<key_data>incoming serialized data</key_data>
</input_data>

here Key_data should be validated to check if it contains anything other than serialized data.

Answer 1

IF FIELDNAME(rootTagname.*:input_data) = 'input_data' THEN

    -- do some thing as per your requirement 
ELSE

  THROW USER EXCEPTION MESSAGE 'some number' VALUES ('no value received for input_data.');

end IF;