Utils.php

<?php
/*
 * Copyright 2012 Jurrie Overgoor <jurrie@narrowxpres.nl>
 * 
 * This file is part of CompetitieBeheer-php-api.
 * 
 * CompetitieBeheer-php-api is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 * 
 * CompetitieBeheer-php-api is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with CompetitieBeheer-php-api. If not, see
 * <http://www.gnu.org/licenses/>.
 */

abstract class Utils {

    public static function ISO8601Date2UnixTimestamp($iso8601) {
        return strtotime($iso8601);
    }

    public static function UnixTimestamp2ISO8601Date($unixTimestamp) {
        return date('c', $unixTimestamp);
    }

    /**
     * This function will convert an ISO8601 period to the number of seconds.
     * The number of seconds a period represents cannot be accurately calculated if you don't know the start of the period, so you need to give this.
     * @param string $iso8601period The ISO8601 period to be converted
     * @param long $fromDateTime The start of the period, given as a Unix timestamp
     */
    public static function ISO8601Period2UnixTimestamp($iso8601period, $fromDateTime) {
        if (class_exists('DateInterval')) {
            $dateInterval = new DateInterval($iso8601period);
            $toDateTime = strtotime("+" . $dateInterval->format("%y") . " year +" . $dateInterval->format("%m") . " month +" . $dateInterval->format("%d") . " day +" . $dateInterval->format("%h") . " hour +" . $dateInterval->format("%i") . " minute +" . $dateInterval->format("%s") . " second", $fromDateTime);
        } else {
            // Remove the ambiguity of month and minute: make month = x
            $arr = explode('T', $iso8601period);
            $arr[0] = str_replace('M', 'X', $arr[0]);
            $new = implode('T', $arr);

            // EXPAND THE STRING INTO SOMETHING SENSIBLE
            $new = str_replace('S', 'second ', $new);
            $new = str_replace('M', 'minute ', $new);
            $new = str_replace('H', 'hour ', $new);
            $new = str_replace('T', NULL, $new);
            $new = str_replace('D', 'day', $new);
            $new = str_replace('X', 'month ', $new);
            $new = str_replace('Y', 'year ', $new);
            $new = str_replace('P', NULL, $new);

            $toDateTime = strtotime($new, $fromDateTime);
        }
        return $toDateTime - $fromDateTime;
    }

    public static function boolean2String($boolean) {
        return ($boolean ? "true" : "false");
    }

    public static function string2Boolean($string) {
        return strtolower($string) === "true";
    }

}

?>