Add a metadata tag to override notebook direction (ltr/rtl)

Author: m2-farzan

notebook/static/bidi/bidi.js

@@ -13,6 +13,8 @@ define(['bidi/numericshaping'], function(numericshaping) {
   var _loadLocale = function() {
     if (_isMirroringEnabled()) {
       document.body.dir = 'rtl';
+    } else {
+      document.body.dir = 'ltr';
     }
 
     requirejs(['moment'], function (moment) {
@@ -23,7 +25,9 @@ define(['bidi/numericshaping'], function(numericshaping) {
   };
 
   var _isMirroringEnabled = function() {
-    return new RegExp('^(ar|he)').test(_uiLang());
+    if (!IPython.notebook || !IPython.notebook.metadata.direction)
+      return new RegExp('^(ar|he)').test(_uiLang());
+    return (IPython.notebook.metadata.direction == 'rtl');
   };
 
   /**

notebook/static/notebook/js/actions.js

@@ -68,8 +68,11 @@ define([
         'toggle-rtl-layout': {
             cmd: i18n.msg._('toggle rtl layout'),
             help: i18n.msg._('Toggle the screen directionality between left-to-right and right-to-left'),
-            handler: function () {
-              (document.body.getAttribute('dir')=='rtl') ? document.body.setAttribute('dir','ltr') : document.body.setAttribute('dir','rtl');
+            handler: function (env) {
+              var new_direction = document.body.getAttribute('dir') == 'rtl' ? 'ltr' : 'rtl';
+              document.body.setAttribute('dir', new_direction);
+              env.notebook.metadata.direction = new_direction;
+              env.notebook.set_dirty(true);
             }
         },
         'edit-command-mode-keyboard-shortcuts': {

notebook/static/notebook/js/main.js

@@ -77,14 +77,6 @@ requirejs([
 
     // Pull typeahead from the global jquery object
     var typeahead = $.typeahead;
-    
-    try{
-        requirejs(['custom/custom'], function() {});
-        bidi.loadLocale();
-    } catch(err) {
-        console.log("Error processing custom.js. Logging and continuing");
-        console.warn(err);
-    }
 
     // compat with old IPython, remove for IPython > 3.0
     window.CodeMirror = CodeMirror;
@@ -238,4 +230,14 @@ requirejs([
 
     notebook.load_notebook(common_options.notebook_path);
 
+    notebook.events.on('notebook_loaded.Notebook', function() {
+      try{
+          requirejs(['custom/custom'], function() {});
+          bidi.loadLocale();
+      } catch(err) {
+          console.log("Error processing custom.js. Logging and continuing");
+          console.warn(err);
+      }
+    });
+
 });