ProXL allows the user to register a default callback that will be executed if there is no registered callback for the event received, or if all the registered callbacks failed. This is mostly a convenience feature for debugging purposes, as only a few of the event fields can be used.
The fields that can be unified in
)unifies T with the actual event name.
)unifies S with the serial number of the last request processed by the server.
)unifies B, a boolean value, with one of
)unifies D with the ProXL Display the event was read from.