Dave Marshall is already looking ahead to the next major release of PHP, version 5.4, and one of the features it will include - traits. In this new post to his blog, he introduces a "logging trait" he's come up with to make logging simpler in your (Zend Framework) application.
One of the 'traits' I find myself constantly adding to library files is optional logging of it's behaviour. The library class has it's own log method, that checks to see if the instance has had a logger injected and if so, logs the message. I see this as a perfect candidate for becoming a reusable trait, as I tend to have the same code copy/pasted throughout my library classes. The problem is, according to the rfc, traits aren't supposed to have state/properties, which makes it difficult to have a DI setter method in a trait.
He includes the code for his trait example (noting that it may or may not end up working correctly in the 5.4 final release) that sets a logger on a sample class and logs a few values out to the console. It's a simple example, but it shows you one of the most useful things about traits - the "drop in resuability" nature they allow in your libraries and classes.