Helper

helpers should be put in helpers.php or registered dynamically

if you have a lot them, put them in the helpers folder

register a helper

$app->helper('doNothing', function($arg) {
    return $arg;
});

helper in helpers.php

<?php

namespace helpers;

function loadUsers($ids) {
    return $this->db->find($ids);
}

invoke a helper

$app->get('/', function() {
    $this->helper->doNothing(null);
    $this->helper->doSometing();
});