Symfony2.1. How to integrate assetic lessphp filter.

• Add the following package to your composer.json:

"require": {
    ...
    "leafo/lessphp": "dev-master",
    ...
}

• Run php composer.phar update;

#...
assetic:
    #...
    filters:
        lessphp:
            file: %kernel.root_dir%/../vendor/leafo/lessphp/lessc.inc.php
            apply_to: "\.less$"