moving typeset to utils, usage in cell and outputarea

IPython/html/static/base/js/utils.js

@@ -766,6 +766,33 b' define(['
         };
     };
 
+    var typeset = function(element, text) {
+        /**
+         * Apply MathJax rendering to an element, and optionally set its text
+         *
+         * If MathJax is not available, make no changes.
+         *
+         * Returns the output any number of typeset elements, or undefined if
+         * MathJax was not available.
+         *
+         * Parameters
+         * ----------
+         * element: Node, NodeList, or jQuery selection
+         * text: option string
+         */
+        if(!window.MathJax){
+            return;
+        }
+        var $el = element.jquery ? element : $(element);
+        if(arguments.length > 1){
+            $el.text(text);
+        }
+        return $el.map(function(){
+            // MathJax takes a DOM node: $.map makes `this` the context
+            return MathJax.Hub.Queue(["Typeset", MathJax.Hub, this]);
+        });
+    };
+
     var utils = {
         regex_split : regex_split,
         uuid : uuid,
@@ -799,6 +826,7 b' define(['
         load_class: load_class,
         resolve_promises_dict: resolve_promises_dict,
         reject: reject,
+        typeset: typeset,
     };
 
     // Backwards compatability.

IPython/html/static/notebook/js/cell.js

@@ -220,10 +220,7 b' define(['
      * @method typeset
      */
     Cell.prototype.typeset = function () {
-        if (window.MathJax) {
-            var cell_math = this.element.get(0);
-            MathJax.Hub.Queue(["Typeset", MathJax.Hub, cell_math]);
-        }
+        utils.typeset(this.element);
     };
 
     /**

IPython/html/static/notebook/js/outputarea.js

@@ -199,9 +199,7 b' define(['
 
     // typeset with MathJax if MathJax is available
     OutputArea.prototype.typeset = function () {
-        if (window.MathJax){
-            MathJax.Hub.Queue(["Typeset",MathJax.Hub]);
-        }
+        utils.typeset(this.element);
     };
 
 

IPython/html/static/widgets/js/widget.js

@@ -577,19 +577,7 b' define(["widgets/js/manager",'
         },
 
         typeset: function(element, text){
-            // after (optionally) updating a node(list) or jQuery selection's 
-            // text, check if MathJax is available and typeset it
-            var $el = element.jquery ? element : $(element);
-
-            if(arguments.length > 1){
-                $el.text(text);
-            }
-            if(!window.MathJax){
-                return;
-            }
-            return $el.map(function(){
-                return MathJax.Hub.Queue(["Typeset", MathJax.Hub, this]);
-            });
+            utils.typeset.apply(null, arguments);
         },
     });