Config stuff

Module.php

<?php
namespace Foo;

class Module
{
    /* This config willk be cached */
    public function getConfig() { return []; }
    
    /**
     * This config will NOT be cached
     * It will map into 'filters' key of getConfig()
     */
    public function getFilterConfig() 
    {
        return [
            'invokables' => [
                'ToFloat' => function ($input) {
                    return floatval($input);
                }
            ]
        ];
    }
    
    // For more stuff read http://framework.zend.com/manual/current/en/tutorials/config.advanced.html#configuration-mapping-table
}