> Since PHP 5.3, it is possible to leave out the middle part of the ternary operator. Expression expr1 ?: expr3 returns expr1 if expr1 evaluates to TRUE, and expr3 otherwise.

http://php.net/manual/en/language.operators.comparison.php

Kohana 3.2 doesn't require PHP 5.3.

It would be also better to create a variable and pass into function as argument (comment as well)..