1<?php
2
3namespace Sabre\VObject;
4
5/**
6 * Useful utilities for working with various strings.
7 *
8 * @copyright Copyright (C) 2011-2015 fruux GmbH (https://fruux.com/).
9 * @author Evert Pot (http://evertpot.com/)
10 * @license http://sabre.io/license/ Modified BSD License
11 */
12class StringUtil {
13
14    /**
15     * Returns true or false depending on if a string is valid UTF-8
16     *
17     * @param string $str
18     * @return bool
19     */
20    static function isUTF8($str) {
21
22        // First check.. mb_check_encoding
23        if (!mb_check_encoding($str, 'UTF-8')) {
24            return false;
25        }
26
27        // Control characters
28        if (preg_match('%(?:[\x00-\x08\x0B-\x0C\x0E\x0F])%', $str)) {
29            return false;
30        }
31
32        return true;
33
34    }
35
36    /**
37     * This method tries its best to convert the input string to UTF-8.
38     *
39     * Currently only ISO-5991-1 input and UTF-8 input is supported, but this
40     * may be expanded upon if we receive other examples.
41     *
42     * @param string $str
43     * @return string
44     */
45    static function convertToUTF8($str) {
46
47        $encoding = mb_detect_encoding($str , array('UTF-8','ISO-8859-1'), true);
48
49        if ($encoding === 'ISO-8859-1') {
50            $newStr = utf8_encode($str);
51        } else {
52            $newStr = $str;
53        }
54
55        // Removing any control characters
56        return (preg_replace('%(?:[\x00-\x08\x0B-\x0C\x0E\x0F])%', '', $newStr));
57
58    }
59
60}
61
62