From e588fb8f05d07c1244b066d97cdd2fb27306ee85 Mon Sep 17 00:00:00 2001
From: polesye <s2pak.anton@gmail.com>
Date: Wed, 24 Sep 2014 14:47:55 +0300
Subject: [PATCH] TNL-272: Fix double loading of cms-modules.js.

---
 .../pipeline_js/templates/xmodule.js          | 35 +++++----
 common/djangoapps/terrain/ui_helpers.py       | 72 +++++++++++++------
 2 files changed, 73 insertions(+), 34 deletions(-)

diff --git a/common/djangoapps/pipeline_js/templates/xmodule.js b/common/djangoapps/pipeline_js/templates/xmodule.js
index 4004342145..34093e3231 100644
--- a/common/djangoapps/pipeline_js/templates/xmodule.js
+++ b/common/djangoapps/pipeline_js/templates/xmodule.js
@@ -19,19 +19,28 @@ define(["jquery", "underscore", "mathjax", "codemirror", "tinymce",
         'define': define
     };
 
-    var urls = ${urls};
-    var head = $("head");
-    var deferred = $.Deferred();
-    var numResources = urls.length;
-    $.each(urls, function (i, url) {
-        head.append($("<script/>", {src: url}));
-        // Wait for all the scripts to execute.
-        require([url], function () {
-            if (i === numResources - 1) {
-               deferred.resolve();
+    /**
+     * Loads all modules one-by-one in exact order.
+     * The module should be used until we'll use RequireJS for XModules.
+     * @param {Array} modules A list of urls.
+     * @return {jQuery Promise}
+     **/
+    var requireQueue = function(modules) {
+        var deferred = $.Deferred();
+        var loadScript = function (queue) {
+            // Loads the next script if queue is not empty.
+            if (queue.length) {
+                require([queue.shift()], function() {
+                    loadScript(queue);
+                });
+            } else {
+                deferred.resolve();
             }
-        });
-    });
+        };
 
-    return deferred.promise();
+        loadScript(modules.concat());
+        return deferred.promise();
+    };
+
+    return requireQueue(${urls});
 });
diff --git a/common/djangoapps/terrain/ui_helpers.py b/common/djangoapps/terrain/ui_helpers.py
index 76f51594d3..cb05ef051f 100644
--- a/common/djangoapps/terrain/ui_helpers.py
+++ b/common/djangoapps/terrain/ui_helpers.py
@@ -57,7 +57,13 @@ REQUIREJS_WAIT = {
     re.compile(r'^\s*Files & Uploads'): [
         'js/base', 'jquery.ui', 'coffee/src/main', 'underscore',
         'js/views/assets', 'js/views/asset'
-    ]
+    ],
+
+    # Pages
+    re.compile('^Pages \|'): [
+        'js/models/explicit_url', 'coffee/src/views/tabs',
+        'xmodule', 'coffee/src/main', 'xblock/cms.runtime.v1'
+    ],
 }
 
 
@@ -147,24 +153,7 @@ class RequireJSError(Exception):
     pass
 
 
-@world.absorb
-def wait_for_requirejs(dependencies=None):
-    """
-    If requirejs is loaded on the page, this function will pause
-    Selenium until require is finished loading the given dependencies.
-    If requirejs is not loaded on the page, this function will return
-    immediately.
-
-    :param dependencies: a list of strings that identify resources that
-        we should wait for requirejs to load. By default, requirejs will only
-        wait for jquery.
-    """
-    if not dependencies:
-        dependencies = ["jquery"]
-    # stick jquery at the front
-    if dependencies[0] != "jquery":
-        dependencies.insert(0, "jquery")
-
+def load_requrejs_modules(dependencies, callback="callback(true);"):
     javascript = """
         var callback = arguments[arguments.length - 1];
         if(window.require) {{
@@ -175,16 +164,17 @@ def wait_for_requirejs(dependencies=None):
           addEventListener("beforeunload", unloadHandler);
           addEventListener("unload", unloadHandler);
           require({deps}, function($) {{
+            var modules = arguments;
             setTimeout(function() {{
               removeEventListener("beforeunload", unloadHandler);
               removeEventListener("unload", unloadHandler);
-              callback(true);
+              {callback}
             }}, 50);
           }});
         }} else {{
           callback(false);
         }}
-    """.format(deps=json.dumps(dependencies))
+    """.format(deps=json.dumps(dependencies), callback=callback)
     for _ in range(5):  # 5 attempts max
         try:
             result = world.browser.driver.execute_async_script(dedent(javascript))
@@ -217,6 +207,46 @@ def wait_for_requirejs(dependencies=None):
             return result
 
 
+def wait_for_xmodules_to_load():
+    """
+    If requirejs is loaded on the page, this function will pause
+    Selenium until require is finished loading all xmodules.
+    If requirejs is not loaded on the page, this function will return
+    immediately.
+    """
+    callback = """
+        if (modules[0] && modules[0].done) {{
+            modules[0].done(function () {{callback(true)}});
+        }}
+    """
+    return load_requrejs_modules(["xmodule"], callback)
+
+
+@world.absorb
+def wait_for_requirejs(dependencies=None):
+    """
+    If requirejs is loaded on the page, this function will pause
+    Selenium until require is finished loading the given dependencies.
+    If requirejs is not loaded on the page, this function will return
+    immediately.
+
+    :param dependencies: a list of strings that identify resources that
+        we should wait for requirejs to load. By default, requirejs will only
+        wait for jquery.
+    """
+    if not dependencies:
+        dependencies = ["jquery"]
+    # stick jquery at the front
+    if dependencies[0] != "jquery":
+        dependencies.insert(0, "jquery")
+
+    result = load_requrejs_modules(dependencies)
+    if result and "xmodule" in dependencies:
+        result = wait_for_xmodules_to_load()
+
+    return result
+
+
 @world.absorb
 def wait_for_ajax_complete():
     """