lib/html2text/override.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Run time overrides for Html2Text
  19  *
  20  * This allows us to monkey patch the mb_* functions used in Html2Text to use Moodle's core_text functionality.
  21  *
  22  * @package    core
  23  * @copyright  2016 Andrew Nicols <andrew@nicols.uk>
  24  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26
  27 namespace Html2Text;
  28
  29 /**
  30  * Set the encoding to be used by our monkey patched mb_ functions.
  31  *
  32  * When called with $encoding !== null, we set  the static $intenalencoding
  33  * variable, which is used for subsequent calls.
  34  *
  35  * When called with no value for $encoding, we return the previously defined
  36  * $internalencoding.
  37  *
  38  * This is necessary as we need to maintain the state of mb_internal_encoding
  39  * across calls to other mb_* functions. Check how it is used in the other mb_*
  40  * functions defined here - if no encoding is provided we fallback to what was
  41  * set here, otherwise we used the given encoding.
  42  *
  43  * @staticvar string $internalencoding The encoding to be used across mb_* calls.
  44  * @param     string $encoding When given, sets $internalencoding
  45  * @return    mixed
  46  */
  47 function mb_internal_encoding($encoding = null) {
  48     static $internalencoding = 'utf-8';
  49     if ($encoding !== null) {
  50         $internalencoding = $encoding;
  51         return true;
  52     } else {
  53         return $internalencoding;
  54     }
  55 }
  56
  57 /**
  58  * Performs a multi-byte safe substr() operation based on number of characters.
  59  * Position is counted from the beginning of str. First character's position is
  60  * 0. Second character position is 1, and so on.
  61  *
  62  * @param string $str      The string to extract the substring from.
  63  * @param int    $start    If start is non-negative, the returned string will
  64  *                         start at the start'th position in string, counting
  65  *                         from zero. For instance, in the string 'abcdef',
  66  *                         the character at position 0 is 'a', the character
  67  *                         at position 2 is 'c', and so forth.
  68  * @param int    $length   Maximum number of characters to use from str. If
  69  *                         omitted or NULL is passed, extract all characters
  70  *                         to the end of the string.
  71  * @param string $encoding The encoding parameter is the character encoding.
  72  *                         If it is omitted, the internal character encoding
  73  *                         value will be used.
  74  *
  75  * @return string The portion of str specified by the start and length parameters.
  76  */
  77 function mb_substr($str, $start, $length = null, $encoding = null) {
  78     if ($encoding === null) {
  79         $encoding = mb_internal_encoding();
  80     }
  81     return \core_text::substr($str, $start, $length, $encoding);
  82 }
  83
  84 /**
  85  * Gets the length of a string.
  86  *
  87  * @param string $str      The string being checked for length.
  88  * @param string $encoding The encoding parameter is the character encoding.
  89  *                         If it is omitted, the internal character encoding
  90  *                         value will be used.
  91  *
  92  * @return int The number of characters in str having character encoding $encoding.
  93  *             A multibyte character is counted as 1.
  94  */
  95 function mb_strlen($str, $encoding = null) {
  96     if ($encoding === null) {
  97         $encoding = mb_internal_encoding();
  98     }
  99     return \core_text::strlen($str, $encoding);
 100 }
 101
 102 /**
 103  * Returns $str with all alphabetic chatacters converted to lowercase.
 104  *
 105  * @param string $str      The string being lowercased.
 106  * @param string $encoding The encoding parameter is the character encoding.
 107  *                         If it is omitted, the internal character encoding
 108  *                         value will be used.
 109  *
 110  * @return string The string with all alphabetic characters converted to lowercase.
 111  */
 112 function mb_strtolower($str, $encoding = null) {
 113     if ($encoding === null) {
 114         $encoding = mb_internal_encoding();
 115     }
 116     return \core_text::strtolower($str, $encoding);
 117 }
 118
 119 /**
 120  *
 121  * @param string The string being uppercased
 122  * @param string $encoding The encoding parameter is the character encoding.
 123  *                         If it is omitted, the internal character encoding
 124  *                         value will be used.
 125  *
 126  * @return string The string with all alphabetic characters converted to uppercase.
 127  */
 128 function mb_strtoupper($str, $encoding = null) {
 129     if ($encoding === null) {
 130         $encoding = mb_internal_encoding();
 131     }
 132     return \core_text::strtoupper($str, $encoding);
 133 }