A logger is simply a function that is called with a single argument, which is a representation of the event to be logged. The only constraint is that said log event should be either a string or an object that supports __toString.

One event class is predefined, EarthIT_Logging_AnnotatedEvent. This wraps another log event and associated metadata such as log level or begin and end times, which your logging function may look at.

A LogHelperGears trait is defind that makes it easier to create and log EarthIT_Logging_AnnotatedEvents by calling $this->debug(...), $this->log(...), or $this->warn(...).

A few basic logging classes are provided, also.