How to check if a value exists using computed attributes ?

Elami6 years ago

Hi,

I have a question regarding the computed attributes. I currently have a computed attribute that checks the value of a variable named "event".
I have the following expression :
event==195&&io195>0?io195+"_"+io196:null
It works great so far, but I have a little issue.

When "event" doesn't exist, I have the following message appearing in the logs :
WARN: Attribute computation error - org.traccar.handler.ComputedAttributesHandler.computeAttribute@102![0,5]: 'event == 195 && io195 > 0? io195 + '_' + io196 : null;' undefined variable event - Variable (... < ComputedAttributesHandler:102 < *:113 < BaseDataHandler:27 < ... < *:29 < ... < *:29 < ... < *:29 < ... < ExtendedObjectDecoder:60 < ...)

Is there any way to hide this message in the logs, or even better, to check if "event" is true before running the function ?

Thank you.