MDL-43856 MathJax: Add a setting for additional delimiters to support e.g. ASCIIMATH

filter/mathjaxloader/filter.php

@@ -133,6 +133,7 @@ class filter_mathjaxloader extends moodle_text_filter {
      */
     public function filter($text, array $options = array()) {
         $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>".
@@ -151,7 +152,15 @@ class filter_mathjaxloader extends moodle_text_filter {
         $hasdisplay = (strpos($text, '$$') !== false) ||
                       (strpos($text, '\\[') !== false && strpos($text, '\\]') !== false);
 
-        if ($hasinline || $hasdisplay) {
+        $hasextra = false;
+
+        foreach ($extradelimiters as $extra) {
+            if ($extra && strpos($text, $extra) !== false) {
+                $hasextra = true;
+                break;
+            }
+        }
+        if ($hasinline || $hasdisplay || $hasextra) {
             // Only call init if there is at least one equation on the page.
             $this->lazy_init();
             return '<span class="nolink"><span class="filter_mathjaxloader_equation">' . $text . '</span></span>';

filter/mathjaxloader/lang/en/filter_mathjaxloader.php

@@ -15,18 +15,18 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
- * Strings for component 'filter_mathjax', language 'en'.
+ * Strings for component 'filter_mathjaxloader', language 'en'.
  *
- * Note: use filter/mathjax/cli/update_lang_files.php script to import strings from upstream JS lang files.
- *
- * @package    filter_mathjax
+ * @package    filter_mathjaxloader
  * @copyright  1999 onwards Martin Dougiamas  {@link http://moodle.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-
-//== Custom Moodle strings that are not part of upstream MathJax ==
 $string['filtername'] = 'MathJax';
+$string['additionaldelimiters'] = 'Additional equation delimiters';
+$string['additionaldelimiters_help'] = 'MathJax filter parses text for equations contained within delimiter characters.
+
+The list of recognised delimiter characters can be added to here (e.g. AsciiMath uses `). Delimiters can contain multiple characters and multiple delimiters can be separated with commas.';
 $string['httpurl'] = 'HTTP MathJax URL';
 $string['httpurl_help'] = 'Full URL to MathJax library. Used when the page is loaded via http.';
 $string['httpsurl'] = 'HTTPS MathJax URL';

filter/mathjaxloader/settings.php

@@ -76,4 +76,11 @@ MathJax.Hub.Config({
 
     $settings->add($item);
 
+    $item = new admin_setting_configtext('filter_mathjaxloader/additionaldelimiters',
+                                         new lang_string('additionaldelimiters', 'filter_mathjaxloader'),
+                                         new lang_string('additionaldelimiters_help', 'filter_mathjaxloader'),
+                                         '',
+                                         PARAM_RAW);
+    $settings->add($item);
+
 }