MDL-43856 MathJax: Improvements to the MathJax filter

* Remove all traces of mathjax from the atto equation editor - it is filter agnostic
* Add a M.core.event module for core events that can be published/subscribed to by plugins (loose coupling)
* Add a FILTER_CONTENT_UPDATED event so plugins can tell the filter system when nodes are added to the page
* Implement a listener for this event in the MathJax filter
* Fire this event from the equation editor and from the glossary filter
* Add a nolink tag to the mathjax filter, so equations will not be processed by the other filters
* Add a smarter throttle function to the equation editor preview updates (Y.throttle is dumb)

filter/glossary/yui/build/moodle-filter_glossary-autolinker/moodle-filter_glossary-autolinker-debug.js

@@ -72,6 +72,8 @@ Y.extend(AUTOLINKER, Y.Base, {
                     alertpanel = new M.core.alert({title:data.entries[key].concept,
                         message:definition, modal:false, yesLabel: M.util.get_string('ok', 'moodle')});
                     alertpanel.show();
+                    Y.fire(M.core.event.FILTER_CONTENT_UPDATED, {nodes: (new Y.NodeList(alertpanel.get('boundingBox')))});
+
                     Y.Node.one('#id_yuialertconfirm-' + alertpanel.get('COUNT')).focus();
                 }
 
@@ -141,6 +143,7 @@ M.filter_glossary.init_filter_autolinking = function(config) {
         "json-parse",
         "event-delegate",
         "overlay",
+        "moodle-core-event",
         "moodle-core-notification-alert"
     ]
 });

filter/glossary/yui/build/moodle-filter_glossary-autolinker/moodle-filter_glossary-autolinker.js

@@ -72,6 +72,8 @@ Y.extend(AUTOLINKER, Y.Base, {
                     alertpanel = new M.core.alert({title:data.entries[key].concept,
                         message:definition, modal:false, yesLabel: M.util.get_string('ok', 'moodle')});
                     alertpanel.show();
+                    Y.fire(M.core.event.FILTER_CONTENT_UPDATED, {nodes: (new Y.NodeList(alertpanel.get('boundingBox')))});
+
                     Y.Node.one('#id_yuialertconfirm-' + alertpanel.get('COUNT')).focus();
                 }
 
@@ -141,6 +143,7 @@ M.filter_glossary.init_filter_autolinking = function(config) {
         "json-parse",
         "event-delegate",
         "overlay",
+        "moodle-core-event",
         "moodle-core-notification-alert"
     ]
 });

filter/glossary/yui/src/autolinker/js/autolinker.js

@@ -70,6 +70,8 @@ Y.extend(AUTOLINKER, Y.Base, {
                     alertpanel = new M.core.alert({title:data.entries[key].concept,
                         message:definition, modal:false, yesLabel: M.util.get_string('ok', 'moodle')});
                     alertpanel.show();
+                    Y.fire(M.core.event.FILTER_CONTENT_UPDATED, {nodes: (new Y.NodeList(alertpanel.get('boundingBox')))});
+
                     Y.Node.one('#id_yuialertconfirm-' + alertpanel.get('COUNT')).focus();
                 }
 

filter/glossary/yui/src/autolinker/meta/autolinker.json

@@ -7,6 +7,7 @@
         "json-parse",
         "event-delegate",
         "overlay",
+        "moodle-core-event",
         "moodle-core-notification-alert"
     ]
   }

filter/mathjaxloader/filter.php

@@ -132,14 +132,29 @@ public function lazy_init() {
      * @param array $options The filter options.
      */
     public function filter($text, array $options = array()) {
-        // This replaces <tex> blah </tex> syntax with [tex] blah [/tex] syntax
-        // because MathJax cannot handle html tags as delimiters.
+        $legacy = get_config('filter_mathjaxloader', 'texfiltercompatibility');
+        if ($legacy) {
+            // This replaces any of the tex filter maths delimiters with the default for inline maths in MathJAX "\( blah \)".
+            // <tex.*> blah </tex>
+            $text = preg_replace('|<(/?) *tex( [^>]*)?>|u', '[\1tex]', $text);
+            // [tex.*] blah [/tex]
+            $text = str_replace('[tex]', '\\(', $text);
+            $text = str_replace('[/tex]', '\\)', $text);
+            // $$ blah $$
+            $text = preg_replace('|\$\$[\S\s]\$\$|u', '\\(\1\\)', $text);
+            // \[ blah \]
+            $text = str_replace('\\[', '\\(', $text);
+            $text = str_replace('\\]', '\\)', $text);
+        }
+
+        $hasinline = strpos($text, '\\(') !== false && strpos($text, '\\)') !== false;
+        $hasdisplay = (strpos($text, '$$') !== false) ||
+                      (strpos($text, '\\[') !== false && strpos($text, '\\]') !== false);
 
-        $text = preg_replace('|<(/?) *tex( [^>]*)?>|u', '[\1tex]', $text);
-        if (strpos($text, '$$') !== false || strpos($text, '\\[') !== false || strpos($text, '[tex]') !== false) {
+        if ($hasinline || $hasdisplay) {
             // Only call init if there is at least one equation on the page.
             $this->lazy_init();
-            return '<span class="filter_mathjaxloader_equation">' . $text . '</span>';
+            return '<span class="nolink"><span class="filter_mathjaxloader_equation">' . $text . '</span></span>';
         }
         return $text;
     }

filter/mathjaxloader/lang/en/filter_mathjaxloader.php

@@ -29,10 +29,18 @@
 $string['filtername'] = 'MathJax';
 $string['httpurl'] = 'HTTP MathJax URL';
 $string['httpurl_help'] = 'Full URL to MathJax library. Used when the page is loaded via http.';
-$string['httpsurl'] = 'HTTP MathJax URL';
+$string['httpsurl'] = 'HTTPS MathJax URL';
 $string['httpsurl_help'] = 'Full URL to MathJax library. Used when the page is loaded via https (secure). ';
+$string['texfiltercompatibility'] = 'Tex filter compatibility';
+$string['texfiltercompatibility_help'] = 'The MathJax filter can be used as a replacement for the Tex filter. 
+
+To support all the delimiters supported by the Tex filter MathJax will be configured to display all equations "inline" with the tex.';
 $string['localinstall'] = 'Local MathJax installation';
-$string['localinstall_help'] = 'The default MathJAX configuration uses the CDN version of MathJAX, but MathJAX can be installed locally if required. Some reasons this might be useful are to save on bandwidth - or because of local proxy restrictions. To use a local installation of MathJAX, first download the full MathJax library from http://www.mathjax.org/. Then install it on a web server. Finally update the MathJax filter settings httpurl and/or httpsurl to point to the local MathJax.js url.';
+$string['localinstall_help'] = 'The default MathJAX configuration uses the CDN version of MathJAX, but MathJAX can be installed locally if required. 
+
+Some reasons this might be useful are to save on bandwidth - or because of local proxy restrictions. 
+
+To use a local installation of MathJAX, first download the full MathJax library from http://www.mathjax.org/. Then install it on a web server. Finally update the MathJax filter settings httpurl and/or httpsurl to point to the local MathJax.js url.';
 $string['mathjaxsettings'] = 'MathJax configuration';
-$string['mathjaxsettings_desc'] = 'The default MathJAX configuration should be appropriate for most users, but MathJax is highly configurable and advanced users may want to provide a different configuration. More information on MathJax configuration options is available here: http://docs.mathjax.org/en/latest/options/index.html';
+$string['mathjaxsettings_desc'] = 'The default MathJAX configuration should be appropriate for most users, but MathJax is highly configurable and any of the standard MathJax configuration options can be added here.';
 

filter/mathjaxloader/settings.php

@@ -44,6 +44,12 @@
                                          PARAM_RAW);
     $settings->add($item);
 
+    $item = new admin_setting_configcheckbox('filter_mathjaxloader/texfiltercompatibility',
+                                         new lang_string('texfiltercompatibility', 'filter_mathjaxloader'),
+                                         new lang_string('texfiltercompatibility_help', 'filter_mathjaxloader'),
+                                         0);
+    $settings->add($item);
+
     $default = '
 MathJax.Hub.Config({
     config: ["MMLorHTML.js", "Safe.js"],
@@ -58,19 +64,6 @@
         mpMouse: true
     },
     errorSettings: { message: ["!"] },
-    tex2jax: {
-        skipTags: ["script","noscript","style","textarea"],
-        inlineMath: [
-            ["\\\\(","\\\\)"],
-            ["$$","$$"],
-            ["\\\\[","\\\\]"]
-        ],
-        displayMath: [
-            ["[tex]","[/tex]"],
-        ],
-        balanceBraces: true,
-        preview: "TeX"
-    },
     skipStartupTypeset: true,
     messageStyle: "none"
 });

filter/mathjaxloader/yui/build/moodle-filter_mathjaxloader-loader/moodle-filter_mathjaxloader-loader-debug.js

@@ -38,8 +38,26 @@ M.filter_mathjaxloader = M.filter_mathjaxloader || {
             MathJax.Hub.Queue(["Typeset",MathJax.Hub,node.getDOMNode()]);
         });
         MathJax.Hub.Configured();
+
+        // Listen for events triggered when new text is added to a page that needs
+        // processing by a filter.
+
+        Y.on(M.core.event.FILTER_CONTENT_UPDATED, this.contentUpdated, this);
+    },
+
+    /**
+     * Handle content updated events - typeset the new content.
+     * @method contentUpdated
+     * @param Y.Event - Custom event with "nodes" indicating the root of the updated nodes.
+     */
+    contentUpdated: function(event) {
+        event.nodes.each(function (node) {
+            node.all('.filter_mathjaxloader_equation').each(function(node) {
+                MathJax.Hub.Queue(["Typeset",MathJax.Hub,node.getDOMNode()]);
+            });
+        });
     }
 };
 
 
-}, '@VERSION@', {"requires": ["mathjax"]});
+}, '@VERSION@', {"requires": ["moodle-core-event", "mathjax"]});

filter/mathjaxloader/yui/build/moodle-filter_mathjaxloader-loader/moodle-filter_mathjaxloader-loader.js

@@ -38,8 +38,26 @@ M.filter_mathjaxloader = M.filter_mathjaxloader || {
             MathJax.Hub.Queue(["Typeset",MathJax.Hub,node.getDOMNode()]);
         });
         MathJax.Hub.Configured();
+
+        // Listen for events triggered when new text is added to a page that needs
+        // processing by a filter.
+
+        Y.on(M.core.event.FILTER_CONTENT_UPDATED, this.contentUpdated, this);
+    },
+
+    /**
+     * Handle content updated events - typeset the new content.
+     * @method contentUpdated
+     * @param Y.Event - Custom event with "nodes" indicating the root of the updated nodes.
+     */
+    contentUpdated: function(event) {
+        event.nodes.each(function (node) {
+            node.all('.filter_mathjaxloader_equation').each(function(node) {
+                MathJax.Hub.Queue(["Typeset",MathJax.Hub,node.getDOMNode()]);
+            });
+        });
     }
 };
 
 
-}, '@VERSION@', {"requires": ["mathjax"]});
+}, '@VERSION@', {"requires": ["moodle-core-event", "mathjax"]});

filter/mathjaxloader/yui/src/loader/js/loader.js

@@ -36,5 +36,23 @@ M.filter_mathjaxloader = M.filter_mathjaxloader || {
             MathJax.Hub.Queue(["Typeset",MathJax.Hub,node.getDOMNode()]);
         });
         MathJax.Hub.Configured();
+
+        // Listen for events triggered when new text is added to a page that needs
+        // processing by a filter.
+
+        Y.on(M.core.event.FILTER_CONTENT_UPDATED, this.contentUpdated, this);
+    },
+
+    /**
+     * Handle content updated events - typeset the new content.
+     * @method contentUpdated
+     * @param Y.Event - Custom event with "nodes" indicating the root of the updated nodes.
+     */
+    contentUpdated: function(event) {
+        event.nodes.each(function (node) {
+            node.all('.filter_mathjaxloader_equation').each(function(node) {
+                MathJax.Hub.Queue(["Typeset",MathJax.Hub,node.getDOMNode()]);
+            });
+        });
     }
 };

filter/mathjaxloader/yui/src/loader/meta/loader.json

@@ -1,6 +1,7 @@
 {
     "moodle-filter_mathjaxloader-loader": {
         "requires": [
+            "moodle-core-event",
             "mathjax"
         ]
     }

lib/editor/atto/plugins/equation/lib.php

@@ -81,6 +81,8 @@ function atto_equation_params_for_js($elementid, $options, $fpoptions) {
                 'elements' => get_config('atto_equation', 'librarygroup4'),
             ));
 
-    return array('texfilteractive' => $texfilteractive, 'contextid' => $context->id, 'library' => $library,
-        'texdocsurl' => get_docs_url('Using_TeX_Notation'));
+    return array('texfilteractive' => $texfilteractive,
+                 'contextid' => $context->id,
+                 'library' => $library,
+                 'texdocsurl' => get_docs_url('Using_TeX_Notation'));
 }

lib/editor/atto/plugins/equation/settings.php

@@ -165,4 +165,5 @@
                                                     $desc,
                                                     $default);
     $settings->add($setting);
+
 }