Since our CMS Drupal does occasionally assign the value zero to userID…

[btruong]

…, we need to allow segment calls to still validate when the userId is zero, so instead using not empty, using isset would allow the call to validate if the userId value happens to be zero

[f2prateek]

0 is indeed a valid userId as per our spec and it seems reasonable to not prevent users from using it unless our spec defines it as invalid.

On the other hand it might certainly bite people if they have a bug and send data for multiple users under the same ID.

[f2prateek]

After thinking this through, I'd rather leave the empty check since that guards against an empty string while isset does not.

Can you fix this in your CMS upstream of the library?

[dustincurrie]

You can test for not empty while allowing zero in PHP with
!empty($message["userId"]) || $message["userId"] == '0'

With the == operator, you get type juggling, so this will work for the integer 0 and string '0'

Can this PR be updated and re-opened?

[f2prateek]

@dustincurrie The 2nd part of my hesitation still stands #77 (comment).

On the other hand it might certainly bite people if they have a bug and send data for multiple users under the same ID.