Added a cache_if_anonymous decorator.

common/djangoapps/student/views.py

@@ -20,11 +20,12 @@ from django.shortcuts import redirect
 from mitxmako.shortcuts import render_to_response, render_to_string
 from django.core.urlresolvers import reverse
 
+from django_future.csrf import ensure_csrf_cookie
+from student.models import Registration, UserProfile, PendingNameChange, PendingEmailChange, CourseEnrollment
+from util.cache import cache_if_anonymous 
 from xmodule.course_module import CourseDescriptor
 from xmodule.modulestore.django import modulestore
-from django_future.csrf import ensure_csrf_cookie
 
-from models import Registration, UserProfile, PendingNameChange, PendingEmailChange, CourseEnrollment
 
 log = logging.getLogger("mitx.student")
 
@@ -39,6 +40,7 @@ def csrf_token(context):
 
 
 @ensure_csrf_cookie
+@cache_if_anonymous
 def index(request):
     ''' Redirects to main page -- info page if user authenticated, or marketing if not
     '''
@@ -492,13 +494,14 @@ def accept_name_change(request):
 
 
 @ensure_csrf_cookie
+@cache_if_anonymous
 def course_info(request, course_id):
     # This is the advertising page for a student to look at the course before signing up
     csrf_token = csrf(request)['csrf_token']
     course_loc = CourseDescriptor.id_to_location(course_id)
     course = modulestore().get_item(course_loc)
     # TODO: Couse should be a model
-    return render_to_response('portal/course_about.html', {'csrf': csrf_token, 'course': course})
+    return render_to_response('portal/course_about.html', {'course': course})
 
 
 @login_required

common/djangoapps/util/cache.py

@@ -5,6 +5,8 @@ invalidation. Import these instead of django.core.cache.
 Note that 'default' is being preserved for user session caching, which we're 
 not migrating so as not to inconvenience users by logging them all out.
 """
+from functools import wraps
+
 from django.core import cache
 
 # If we can't find a 'general' CACHE defined in settings.py, we simply fall back
@@ -14,3 +16,41 @@ try:
 except Exception:
     cache = cache.cache
 
+def cache_if_anonymous(view_func):
+    """
+    Many of the pages in edX are identical when the user is not logged
+    in, but should not be cached when the user is logged in (because 
+    of the navigation bar at the top with the username). 
+    
+    The django middleware cache does not handle this correctly, because
+    we access the session to put the csrf token in the header. This adds
+    the cookie to the vary header, and so every page is cached seperately
+    for each user (because each user has a different csrf token).
+    
+    Note that this decorator should only be used on views that do not
+    contain the csrftoken within the html. The csrf token can be included
+    in the header by ordering the decorators as such:
+    
+    @ensure_csrftoken
+    @cache_if_anonymous
+    def myView(request):
+    """
+    
+    @wraps(view_func)
+    def _decorated(request, *args, **kwargs):
+        if not request.user.is_authenticated():
+            #Use the cache
+            cache_key = "cache_if_anonymous." + request.path
+            response = cache.get(cache_key)
+            if not response:
+                response = view_func(request, *args, **kwargs)
+                cache.set(cache_key, response, 60 * 3)
+            
+            return response
+            
+        else:
+            #Don't use the cache
+            return view_func(request, *args, **kwargs)
+    
+    return _decorated
+    
\ No newline at end of file

lms/djangoapps/courseware/views.py

@@ -19,7 +19,7 @@ from multicourse import multicourse_settings
 from xmodule.modulestore.django import modulestore
 from xmodule.course_module import CourseDescriptor
 
-from util.cache import cache
+from util.cache import cache, cache_if_anonymous
 from student.models import UserTestGroup
 from courseware import grades
 
@@ -51,11 +51,10 @@ def format_url_params(params):
 
 
 @ensure_csrf_cookie
+@cache_if_anonymous
 def courses(request):
-    csrf_token = csrf(request)['csrf_token']
     # TODO: Clean up how 'error' is done.
-    context = {'courses': modulestore().get_courses(),
-               'csrf': csrf_token}
+    context = {'courses': modulestore().get_courses()}
     return render_to_response("courses.html", context)
 
 

lms/djangoapps/static_template_view/views.py

@@ -8,7 +8,7 @@ from django.shortcuts import redirect
 from django.conf import settings
 from django_future.csrf import ensure_csrf_cookie
 
-from util.cache import cache
+from util.cache import cache_if_anonymous 
 
 valid_templates = []
 
@@ -29,6 +29,7 @@ def index(request, template):
         return redirect('/')
 
 @ensure_csrf_cookie
+@cache_if_anonymous
 def render(request, template):
     """
     This view function renders the template sent without checking that it
@@ -36,17 +37,8 @@ def render(request, template):
     not be able to ender any arbitray template name. The correct usage would be:
     
     url(r'^jobs$', 'static_template_view.views.render', {'template': 'jobs.html'}, name="jobs")
-    """
-    cache_key = "static_template_view_render." + template
-    use_cache = not request.user.is_authenticated()
-    
-    response = cache.get(cache_key) if use_cache else None
-    if not response:
-        response = render_to_response('static_templates/' + template, {})
-        if use_cache:
-            cache.set(cache_key, response, 60 * 3)
-    
-    return response
+    """    
+    return render_to_response('static_templates/' + template, {})
     
 
 valid_auth_templates=['help.html']