Add examples of render and render_childe

common/lib/xmodule/xmodule/vertical_module.py

@@ -14,7 +14,7 @@ class VerticalModule(XModule):
     @register_view('student_view')
     def get_html(self):
         return render_template('vert_module.html', {
-            'items': [child.render() for child in self.children]
+            'items': [self.render_child(child) for child in self.children]
         })
 
     def get_progress(self):

common/lib/xmodule/xmodule/xmodule.py

@@ -186,10 +186,35 @@ class XModule(Plugin, HTMLSnippet):
         self.user_preferences = user_preferences
         self.student_state = student_state
 
-    def render(self, view_name):
+    @staticmethod
+    def render(module, view_name):
+        """
+        Render the specified view from the supplied module
+
+        view_name: The string name of the view to render
+        module: The XModule to render
+        """
+        # Make children use the appropriate render context
+        try:
+            setattr(module, 'view_name', view_name)
+            return module.find_view(view_name)()
+        finally:
+            delattr(module, 'view_name')
+
+    def render_child(self, child, view_name=None):
+        """
+        Render a view on a child module. If view_name isn't supplied,
+        render the same view on the child that is currently being rendered on the parent
+        """
+        if view_name is None:
+            view_name = getattr(self, 'view_name')
+
+        return XModule.render(child, view_name)
+
+    def find_view(self, view_name):
         for method_name, method_fn in inspect.getmembers(self, lambda m: inspect.ismethod(m)):
             if getattr(method_fn, 'view_name', None) is not None:
-                return method_fn()
+                return method_fn
 
     @property
     def children(self):