Merge pull request #193 from jdfreder/loadfix

Fix front-end extension loading

notebook/static/base/js/utils.js

@@ -10,34 +10,37 @@ define([
 ], function($, CodeMirror, moment){
     "use strict";
     
-    var load_extensions = function () {
-        // load one or more Jupyter notebook extensions with requirejs
-        
-        var extensions = [];
-        var extension_names = arguments;
-        for (var i = 0; i < extension_names.length; i++) {
-            extensions.push("nbextensions/" + arguments[i]);
-        }
-        
-        require(extensions,
-            function () {
-                for (var i = 0; i < arguments.length; i++) {
-                    var ext = arguments[i];
-                    var ext_name = extension_names[i];
-                    // success callback
-                    console.log("Loaded extension: " + ext_name);
-                    if (ext && ext.load_ipython_extension !== undefined) {
-                        ext.load_ipython_extension();
-                    }
+    /**
+     * Load a single extension.
+     * @param  {string} extension - extension path.
+     * @return {Promise} that resolves to an extension module handle
+     */
+    var load_extension = function (extension) {
+        return new Promise(function(resolve, reject) {
+            require(["nbextensions/" + extension], function(module) {
+                console.log("Loaded extension: " + extension);
+                try {
+                    module.load_ipython_extension();
+                } finally {
+                    resolve(module);
                 }
-            },
-            function (err) {
-                // failure callback
-                console.log("Failed to load extension(s):", err.requireModules, err);
-            }
-        );
+            }, function(err) {
+                reject(err);
+            });
+        });
     };
-    
+
+    /**
+     * Load multiple extensions.
+     * Takes n-args, where each arg is a string path to the extension.
+     * @return {Promise} that resolves to a list of loaded module handles.
+     */
+    var load_extensions = function () {
+        return Promise.all(Array.prototype.map.call(arguments, load_extension)).catch(function(err) {
+            console.error("Failed to load extension" + (err.requireModules.length>1?'s':'') + ":", err.requireModules, err);
+        });
+    };
+
     /**
      * Wait for a config section to load, and then load the extensions specified
      * in a 'load_extensions' key inside it.

notebook/tests/base/utils.js

@@ -20,4 +20,20 @@ casper.notebook_test(function () {
     }, input);
 
     this.test.assertEquals(result, output, "IPython.utils.fixConsole() handles [0m correctly");
+    
+    this.thenEvaluate(function() {
+        define('nbextensions/a', [], function() { window.a = true; });
+        define('nbextensions/c', [], function() { window.c = true; });
+        require(['base/js/utils'], function(utils) {
+            utils.load_extensions('a', 'b', 'c');
+        });
+    }).then(function() {
+        this.waitFor(function() {
+            return this.evaluate(function() { return window.a; });
+        });
+        
+        this.waitFor(function() {
+            return this.evaluate(function() { return window.a; });
+        });
+    });
 });