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Long Term Support Release
<?php // This file is part of Moodle - http://moodle.org/ // // Moodle is free software: you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // Moodle 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 General Public License for more details. // // You should have received a copy of the GNU General Public License // along with Moodle. If not, see <http://www.gnu.org/licenses/>. /** * This filter provides automatic support for MathJax * * @package filter_mathjaxloader * @copyright 2013 Damyon Wiese (damyon@moodle.com) * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ defined('MOODLE_INTERNAL') || die(); /** * Mathjax filtering */ class filter_mathjaxloader extends moodle_text_filter { /* * Perform a mapping of the moodle language code to the equivalent for MathJax. * * @param string $moodlelangcode - The moodle language code - e.g. en_pirate * @return string The MathJax language code. */ public function map_language_code($moodlelangcode) { // List of language codes found in the MathJax/localization/ directory. $mathjaxlangcodes = [ 'ar', 'ast', 'bcc', 'bg', 'br', 'ca', 'cdo', 'ce', 'cs', 'cy', 'da', 'de', 'diq', 'en', 'eo', 'es', 'fa', 'fi', 'fr', 'gl', 'he', 'ia', 'it', 'ja', 'kn', 'ko', 'lb', 'lki', 'lt', 'mk', 'nl', 'oc', 'pl', 'pt', 'pt-br', 'qqq', 'ru', 'scn', 'sco', 'sk', 'sl', 'sv', 'th', 'tr', 'uk', 'vi', 'zh-hans', 'zh-hant' ]; // List of explicit mappings and known exceptions (moodle => mathjax). $explicit = [ 'cz' => 'cs', 'pt_br' => 'pt-br', 'zh_tw' => 'zh-hant', 'zh_cn' => 'zh-hans', ]; // If defined, explicit mapping takes the highest precedence. if (isset($explicit[$moodlelangcode])) { return $explicit[$moodlelangcode]; } // If there is exact match, it will be probably right. if (in_array($moodlelangcode, $mathjaxlangcodes)) { return $moodlelangcode; } // Finally try to find the best matching mathjax pack. $parts = explode('_', $moodlelangcode, 2); if (in_array($parts[0], $mathjaxlangcodes)) { return $parts[0]; } // No more guessing, use English. return 'en'; } /* * Add the javascript to enable mathjax processing on this page. * * @param moodle_page $page The current page. * @param context $context The current context. */ public function setup($page, $context) { if ($page->requires->should_create_one_time_item_now('filter_mathjaxloader-scripts')) { $url = get_config('filter_mathjaxloader', 'httpsurl'); $lang = $this->map_language_code(current_language()); $url = new moodle_url($url, array('delayStartupUntil' => 'configured'));< $moduleconfig = array( < 'name' => 'mathjax', < 'fullpath' => $url < ); < < $page->requires->js_module($moduleconfig);> $page->requires->js($url);$config = get_config('filter_mathjaxloader', 'mathjaxconfig'); $wwwroot = new moodle_url('/'); $config = str_replace('{wwwroot}', $wwwroot->out(true), $config); $params = array('mathjaxconfig' => $config, 'lang' => $lang);< $page->requires->yui_module('moodle-filter_mathjaxloader-loader', 'M.filter_mathjaxloader.configure', array($params));> $page->requires->js_call_amd('filter_mathjaxloader/loader', 'configure', [$params]);} } /* * This function wraps the filtered text in a span, that mathjaxloader is configured to process. * * @param string $text The text to filter. * @param array $options The filter options. */ public function filter($text, array $options = array()) { global $PAGE; $legacy = get_config('filter_mathjaxloader', 'texfiltercompatibility'); $extradelimiters = explode(',', get_config('filter_mathjaxloader', 'additionaldelimiters')); if ($legacy) { // This replaces any of the tex filter maths delimiters with the default for inline maths in MathJAX "\( blah \)". // E.g. "<tex.*> blah </tex>". $text = preg_replace('|<(/?) *tex( [^>]*)?>|u', '[\1tex]', $text); // E.g. "[tex.*] blah [/tex]". $text = str_replace('[tex]', '\\(', $text); $text = str_replace('[/tex]', '\\)', $text); // E.g. "$$ blah $$". $text = preg_replace('|\$\$([\S\s]*?)\$\$|u', '\\(\1\\)', $text); // E.g. "\[ blah \]". $text = str_replace('\\[', '\\(', $text); $text = str_replace('\\]', '\\)', $text); } $hasextra = false; foreach ($extradelimiters as $extra) { if ($extra && strpos($text, $extra) !== false) { $hasextra = true; break; } } $hasdisplayorinline = false; if ($hasextra) { // If custom dilimeters are used, wrap whole text to prevent autolinking. $text = '<span class="nolink">' . $text . '</span>'; } else if (preg_match('/\\\\[[(]/', $text) || preg_match('/\$\$/', $text)) { // Only parse the text if there are mathjax symbols in it. The recognized // math environments are \[ \] and $$ $$ for display mathematics and \( \) // for inline mathematics. // Note: 2 separate regexes seems to perform better here than using a single // regex with groupings. // Wrap display and inline math environments in nolink spans. // Do not wrap nested environments, i.e., if inline math is nested // inside display math, only the outer display math is wrapped in // a span. The span HTML inside a LaTex math environment would break // MathJax. See MDL-61981. list($text, $hasdisplayorinline) = $this->wrap_math_in_nolink($text); } if ($hasdisplayorinline || $hasextra) {< $PAGE->requires->yui_module('moodle-filter_mathjaxloader-loader', 'M.filter_mathjaxloader.typeset');> $PAGE->requires->js_call_amd('filter_mathjaxloader/loader', 'typeset');return '<span class="filter_mathjaxloader_equation">' . $text . '</span>'; } return $text; } /** * Find math environments in the $text and wrap them in no link spans * (<span class="nolink"></span>). If math environments are nested, only * the outer environment is wrapped in the span. * * The recognized math environments are \[ \] and $$ $$ for display * mathematics and \( \) for inline mathematics. * * @param string $text The text to filter. * @return array An array containing the potentially modified text and * a boolean that is true if any changes were made to the text. */ protected function wrap_math_in_nolink($text) { $i = 1; $len = strlen($text); $displaystart = -1; $displaybracket = false; $displaydollar = false; $inlinestart = -1; $changesdone = false; // Loop over the $text once. while ($i < $len) { if ($displaystart === -1) { // No display math has started yet. if ($text[$i - 1] === '\\' && $text[$i] === '[') { // Display mode \[ begins. $displaystart = $i - 1; $displaybracket = true; } else if ($text[$i - 1] === '$' && $text[$i] === '$') { // Display mode $$ begins. $displaystart = $i - 1; $displaydollar = true; } else if ($text[$i - 1] === '\\' && $text[$i] === '(') { // Inline math \( begins, not nested inside display math. $inlinestart = $i - 1; } else if ($text[$i - 1] === '\\' && $text[$i] === ')' && $inlinestart > -1) { // Inline math ends, not nested inside display math. // Wrap the span around it. $text = $this->insert_span($text, $inlinestart, $i); $inlinestart = -1; // Reset. $i += 28; // The $text length changed due to the <span>. $len += 28; $changesdone = true; } } else { // Display math open. if (($text[$i - 1] === '\\' && $text[$i] === ']' && $displaybracket) || ($text[$i - 1] === '$' && $text[$i] === '$' && $displaydollar)) { // Display math ends, wrap the span around it. $text = $this->insert_span($text, $displaystart, $i); $displaystart = -1; // Reset. $displaybracket = false; $displaydollar = false; $i += 28; // The $text length changed due to the <span>. $len += 28; $changesdone = true; } } ++$i; } return array($text, $changesdone); } /** * Wrap a portion of the $text inside a no link span * (<span class="nolink"></span>). The whole text is then returned. * * @param string $text The text to modify. * @param int $start The start index of the substring in $text that should * be wrapped in the span. * @param int $end The end index of the substring in $text that should be * wrapped in the span. * @return string The whole $text with the span inserted around * the defined substring. */ protected function insert_span($text, $start, $end) { return substr_replace($text, '<span class="nolink">'. substr($text, $start, $end - $start + 1) .'</span>', $start, $end - $start + 1); } }