helper.php

<?php

define('DATE_FORMAT', 'Y-m-d H:i:s');

function _pr($s, $exit = 0)
{
    if ($s) {
        echo '<pre>', print_r($s, true), '</pre>';
    }

    if ($exit) {
        exit;
    }
}

function _random_string($length)
{
    $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

    $size = strlen($chars);
    $str = '';
    for ($i = 0; $i < $length; $i++) {
        $str .= $chars[rand(0, $size - 1)];
    }

    return $str;
}

function _date_format($date, $format = '')
{
    return date(($format ? $format : DATE_FORMAT), strtotime($date));
}

function _time_elapsed($datetime, $full = false)
{
    $now = new DateTime;
    $ago = new DateTime($datetime);
    $diff = $now->diff($ago);

    $diff->w = floor($diff->d / 7);
    $diff->d -= $diff->w * 7;

    $string = array(
        'y' => 'year',
        'm' => 'month',
        'w' => 'week',
        'd' => 'day',
        'h' => 'hour',
        'i' => 'minute',
        's' => 'second',
    );

    foreach ($string as $k => &$v) {
        if ($diff->$k) {
            $v = $diff->$k . ' ' . $v . ($diff->$k > 1 ? 's' : '');
        } else {
            unset($string[$k]);
        }
    }

    if (!$full) {
        $string = array_slice($string, 0, 1);
    }

    return $string ? implode(', ', $string) . ' ago' : 'just now';
}

function _uuid()
{
    return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
        mt_rand(0, 0xffff), mt_rand(0, 0xffff),
        mt_rand(0, 0xffff),
        mt_rand(0, 0x0fff) | 0x4000,
        mt_rand(0, 0x3fff) | 0x8000,
        mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
    );
}

function _slug($string)
{
    return strtolower(preg_replace('/[^A-Za-z0-9-]+/', '-', $string));
}