MIT CCX: Use CCX Keys

Implement the use of CCX opaque keys throughout the ccx code base

include the new custom ccx id package in the github checkouts list

update the coach dashboard wrapper to get CCX information from the incoming course_id, if possible

update function signatures for all view functions to expect CCX as passed by the dashboard wrapper (default to None), remove calls to get_ccx_for_coach as the ccx is passed in.

update reverse calls in python view code to use a CCXLocator for the URL instead of a CourseLocator

use CCXLocator where necessary

use course id to find ccx, instead of thread local

remove unused method and related tests

use course id for getting ccx

provide course id to the get_current_ccx method

ensure the course id passed in is a CourseKey instance of some type whether it starts out as a string or not

use the provided block to figure out what the course_id should be, then get the ccx for that

redirect to ccx dashboard using coach ccx if no ccx is passed in

update student dashboard listing for ccx to build an appropriate url from a CCXLocator, not from the course locator.

refactor building the ccx locator so we don't have to do it repeatedly

begin test refactoring after ccx_keys introduction

Ensure that when access checking happens, the course_locator form of a ccx locator is used.  This ensures that the access check happens against the course and it is not necesarry to duplicate the entire access control structure for the course.

pick up api change in ccx-keys

create and conditionally use a wrapper for the mixed modulestore returned by xmodule.modulestore.django.modulestore

the wrapper will strip and restore ccx values from CourseKey and UsageKey objects

fix return values on a few methods

remove unused symbol

pull updated ccx-keys package

set course_id on the caching descriptor system to avoid api incompatibilities in some subsystems

use ccx.course instead of self.course

fix get method to find course keys from blocks that are not themselves keys but have a location attribute (which will be a key)

if an item coming out of the db has children, restore the ccx to them as well

if the block passed in has a CCX key, unwrap that before we try to look up the override, otherwise it will never be found.

pick up a change in the ccx keys package that allows for stripping CCX identity from a usage key

begin writing tests to cover this modulestore wrapper

remove the switch_pocs view, the url pattern for it, and the tests that covered it

remove the ccx context and the middleware responsible for setting the current CCX.  These are no longer needed

all dashboard views should raise 404 if a ccx is not provided by the coach_dashboard decorator

code quality

prevent errors resulting from trying to `get` a ccx based on non-unique criteria.

remove obsolete usage of ACTIVE_CCX_KEY

fix setUp method for grading tests to properly create grades for the ccx rather than for the course.

clean up reverse calls

code quality

adding docstrings to clarify purpose of this patch

fix bug in getting ccx for coach

fix grading views to properly fetch a ccx-ified course so that grades for that version will be calculated

fix small errors in modulestore implementation

fix errant merge marker

update call to get_current_ccx after key refactoring merged with tab changes

common/djangoapps/student/models.py

@@ -1195,6 +1195,13 @@ class CourseEnrollment(models.Model):
         """
         if not user.is_authenticated():
             return False
+
+        # unwrap CCXLocators so that we use the course as the access control
+        # source
+        from ccx_keys.locator import CCXLocator
+        if isinstance(course_key, CCXLocator):
+            course_key = course_key.to_course_locator()
+
         try:
             record = CourseEnrollment.objects.get(user=user, course_id=course_key)
             return record.is_active

common/djangoapps/student/views.py

@@ -618,14 +618,10 @@ def dashboard(request):
 
     ccx_membership_triplets = []
     if settings.FEATURES.get('CUSTOM_COURSES_EDX', False):
-        from ccx import ACTIVE_CCX_KEY
         from ccx.utils import get_ccx_membership_triplets
         ccx_membership_triplets = get_ccx_membership_triplets(
             user, course_org_filter, org_filter_out_set
         )
-        # should we deselect any active CCX at this time so that we don't have
-        # to change the URL for viewing a course?  I think so.
-        request.session[ACTIVE_CCX_KEY] = None
 
     context = {
         'enrollment_message': enrollment_message,

common/lib/xmodule/xmodule/modulestore/django.py

@@ -193,6 +193,10 @@ def modulestore():
             settings.MODULESTORE['default'].get('OPTIONS', {})
         )
 
+        if settings.FEATURES.get('CUSTOM_COURSES_EDX'):
+            from ccx.modulestore import CCXModulestoreWrapper
+            _MIXED_MODULESTORE = CCXModulestoreWrapper(_MIXED_MODULESTORE)
+
     return _MIXED_MODULESTORE
 
 

common/lib/xmodule/xmodule/modulestore/split_mongo/caching_descriptor_system.py

@@ -72,6 +72,9 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):
         )
         self.modulestore = modulestore
         self.course_entry = course_entry
+        # set course_id attribute to avoid problems with subsystems that expect
+        # it here. (grading, for example)
+        self.course_id = course_entry.course_key
         self.lazy = lazy
         self.module_data = module_data
         self.default_class = default_class

lms/djangoapps/ccx/__init__.py

-"""
-we use this to mark the active ccx, for use by ccx middleware and some views
-"""
-ACTIVE_CCX_KEY = '_ccx_id'

lms/djangoapps/ccx/modulestore.py

+# -*- coding: utf-8 -*-
+"""A modulestore wrapper
+
+It will 'unwrap' ccx keys on the way in and re-wrap them on the way out
+
+In practical terms this means that when an object is retrieved from modulestore
+using a CCXLocator or CCXBlockUsageLocator as the key, the equivalent
+CourseLocator or BlockUsageLocator will actually be used. And all objects
+returned from the modulestore will have their keys updated to be the CCX
+version that was passed in.
+"""
+from contextlib import contextmanager
+from ccx_keys.locator import CCXLocator, CCXBlockUsageLocator
+from opaque_keys.edx.locator import CourseLocator, BlockUsageLocator
+
+
+def ccx_locator_to_course_locator(ccx_locator):
+    return CourseLocator(
+        org=ccx_locator.org,
+        course=ccx_locator.course,
+        run=ccx_locator.run,
+        branch=ccx_locator.branch,
+        version_guid=ccx_locator.version_guid,
+    )
+
+
+def strip_ccx(val):
+    retval = val
+    ccx_id = None
+    if hasattr(retval, 'ccx'):
+        if isinstance(retval, CCXLocator):
+            ccx_id = retval.ccx
+            retval = ccx_locator_to_course_locator(retval)
+        elif isinstance(object, CCXBlockUsageLocator):
+            ccx_locator = retval.course_key
+            ccx_id = ccx_locator.ccx
+            course_locator = ccx_locator_to_course_locator(ccx_locator)
+            retval = BlockUsageLocator(
+                course_locator, retval.block_type, retval.block_id
+            )
+    if hasattr(retval, 'location'):
+        retval.location, ccx_id = strip_ccx(retval.location)
+    return retval, ccx_id
+
+
+def restore_ccx(val, ccx_id):
+    if isinstance(val, CourseLocator):
+        return CCXLocator.from_course_locator(val, ccx_id)
+    elif isinstance(val, BlockUsageLocator):
+        ccx_key = restore_ccx(val.course_key, ccx_id)
+        val = CCXBlockUsageLocator(ccx_key, val.block_type, val.block_id)
+    if hasattr(val, 'location'):
+        val.location = restore_ccx(val.location, ccx_id)
+    if hasattr(val, 'children'):
+        val.children = restore_ccx_collection(val.children, ccx_id)
+    return val
+
+
+def restore_ccx_collection(field_value, ccx_id):
+    if isinstance(field_value, list):
+        field_value = [restore_ccx(fv, ccx_id) for fv in field_value]
+    elif isinstance(field_value, dict):
+        for key, val in field_value.iteritems():
+            field_value[key] = restore_ccx(val, ccx_id)
+    else:
+        field_value = restore_ccx(field_value, ccx_id)
+    return field_value
+
+
+class CCXModulestoreWrapper(object):
+
+    def __init__(self, modulestore):
+        self._modulestore = modulestore
+
+    def __getattr__(self, name):
+        """pass missing attributes through to _modulestore
+        """
+        return getattr(self._modulestore, name)
+
+    def _clean_locator_for_mapping(self, locator):
+        locator, ccx = strip_ccx(locator)
+        retval = self._modulestore._clean_locator_for_mapping(locator)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def _get_modulestore_for_courselike(self, locator=None):
+        if locator is not None:
+            locator, _ = strip_ccx(locator)
+        return self._modulestore._get_modulestore_for_courselike(locator)
+
+    def fill_in_run(self, course_key):
+        """
+        Some course_keys are used without runs. This function calls the corresponding
+        fill_in_run function on the appropriate modulestore.
+        """
+        course_key, ccx = strip_ccx(course_key)
+        retval = self._modulestore.fill_in_run(course_key)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def has_item(self, usage_key, **kwargs):
+        """
+        Does the course include the xblock who's id is reference?
+        """
+        usage_key, ccx = strip_ccx(usage_key)
+        return self._modulestore.has_item(usage_key, **kwargs)
+
+    def get_item(self, usage_key, depth=0, **kwargs):
+        """
+        see parent doc
+        """
+        usage_key, ccx = strip_ccx(usage_key)
+        retval = self._modulestore.get_item(usage_key, depth, **kwargs)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def get_items(self, course_key, **kwargs):
+        course_key, ccx = strip_ccx(course_key)
+        retval = self._modulestore.get_items(course_key, **kwargs)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def get_course(self, course_key, depth=0, **kwargs):
+        # from nose.tools import set_trace; set_trace()
+        course_key, ccx = strip_ccx(course_key)
+        retval = self._modulestore.get_course(course_key, depth=depth, **kwargs)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def has_course(self, course_id, ignore_case=False, **kwargs):
+        course_id, ccx = strip_ccx(course_id)
+        retval = self._modulestore.has_course(
+            course_id, ignore_case=ignore_case, **kwargs
+        )
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def delete_course(self, course_key, user_id):
+        """
+        See xmodule.modulestore.__init__.ModuleStoreWrite.delete_course
+        """
+        course_key, ccx = strip_ccx(course_key)
+        return self._modulestore.delete_course(course_key, user_id)
+
+    def get_parent_location(self, location, **kwargs):
+        location, ccx = strip_ccx(location)
+        retval = self._modulestore.get_parent_location(location, **kwargs)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def get_block_original_usage(self, usage_key):
+        usage_key, ccx = strip_ccx(usage_key)
+        orig_key, version = self._modulestore.get_block_original_usage(usage_key)
+        if orig_key and ccx:
+            orig_key = restore_ccx_collection(orig_key, ccx)
+        return orig_key, version
+
+    def get_modulestore_type(self, course_id):
+        course_id, ccx = strip_ccx(course_id)
+        retval = self._modulestore.get_modulestore_type(course_id)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def get_orphans(self, course_key, **kwargs):
+        course_key, ccx = strip_ccx(course_key)
+        retval = self._modulestore.get_orphans(course_key, **kwargs)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def clone_course(self, source_course_id, dest_course_id, user_id, fields=None, **kwargs):
+        source_course_id, source_ccx = strip_ccx(source_course_id)
+        dest_course_id, dest_ccx = strip_ccx(dest_course_id)
+        retval = self._modulestore.clone_course(
+            source_course_id, dest_course_id, user_id, fields=fields, **kwargs
+        )
+        if dest_ccx:
+            retval = restore_ccx_collection(retval, dest_ccx)
+        return retval
+
+    def create_item(self, user_id, course_key, block_type, block_id=None, fields=None, **kwargs):
+        course_key, ccx = strip_ccx(course_key)
+        retval = self._modulestore.create_item(
+            user_id, course_key, block_type, block_id=block_id, fields=fields, **kwargs
+        )
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def create_child(self, user_id, parent_usage_key, block_type, block_id=None, fields=None, **kwargs):
+        parent_usage_key, ccx = strip_ccx(parent_usage_key)
+        retval = self._modulestore.create_child(
+            user_id, parent_usage_key, block_type, block_id=block_id, fields=fields, **kwargs
+        )
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def import_xblock(self, user_id, course_key, block_type, block_id, fields=None, runtime=None, **kwargs):
+        course_key, ccx = strip_ccx(course_key)
+        retval = self._modulestore.import_xblock(
+            user_id, course_key, block_type, block_id, fields=fields, runtime=runtime, **kwargs
+        )
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def copy_from_template(self, source_keys, dest_key, user_id, **kwargs):
+        dest_key, ccx = strip_ccx(dest_key)
+        retval = self._modulestore.copy_from_template(
+            source_keys, dest_key, user_id, **kwargs
+        )
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def update_item(self, xblock, user_id, allow_not_found=False, **kwargs):
+        xblock, ccx = strip_ccx(xblock)
+        retval = self._modulestore.update_item(
+            xblock, user_id, allow_not_found=allow_not_found, **kwargs
+        )
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def delete_item(self, location, user_id, **kwargs):
+        location, ccx = strip_ccx(location)
+        retval = self._modulestore.delete_item(location, user_id, **kwargs)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def revert_to_published(self, location, user_id):
+        location, ccx = strip_ccx(location)
+        retval = self._modulestore.revert_to_published(location, user_id)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def create_xblock(self, runtime, course_key, block_type, block_id=None, fields=None, **kwargs):
+        course_key, ccx = strip_ccx(course_key)
+        retval = self._modulestore.create_xblock(
+            runtime, course_key, block_type, block_id=block_id, fields=fields, **kwargs
+        )
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def has_published_version(self, xblock):
+        xblock.scope_ids.usage_id.course_key, ccx = strip_ccx(
+            xblock.scope_ids.usage_id.course_key
+        )
+        retval = self._modulestore.has_published_version(xblock)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def publish(self, location, user_id, **kwargs):
+        location, ccx = strip_ccx(location)
+        retval = self._modulestore.publish(location, user_id, **kwargs)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def unpublish(self, location, user_id, **kwargs):
+        location, ccx = strip_ccx(location)
+        retval = self._modulestore.unpublish(location, user_id, **kwargs)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def convert_to_draft(self, location, user_id):
+        location, ccx = strip_ccx(location)
+        retval = self._modulestore.convert_to_draft(location, user_id)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def has_changes(self, xblock):
+        xblock.location, ccx = strip_ccx(xblock.location)
+        retval = self._modulestore.has_changes(xblock)
+        if ccx:
+            retval = restore_ccx_collection(retval, ccx)
+        return retval
+
+    def check_supports(self, course_key, method):
+        course_key, _ = strip_ccx(course_key)
+        return self._modulestore.check_supports(course_key, method)
+
+    @contextmanager
+    def branch_setting(self, branch_setting, course_id=None):
+        """
+        A context manager for temporarily setting the branch value for the given course' store
+        to the given branch_setting.  If course_id is None, the default store is used.
+        """
+        course_id, _ = strip_ccx(course_id)
+        with self._modulestore.branch_setting(branch_setting, course_id):
+            yield
+
+    @contextmanager
+    def bulk_operations(self, course_id, emit_signals=True):
+        course_id, _ = strip_ccx(course_id)
+        with self._modulestore.bulk_operations(course_id, emit_signals=emit_signals):
+            yield

lms/djangoapps/ccx/overrides.py

@@ -3,16 +3,18 @@ API related to providing field overrides for individual students.  This is used
 by the individual custom courses feature.
 """
 import json
-import threading
-
-from contextlib import contextmanager
+import logging
 
 from django.db import transaction, IntegrityError
 
 from courseware.field_overrides import FieldOverrideProvider  # pylint: disable=import-error
-from ccx import ACTIVE_CCX_KEY  # pylint: disable=import-error
+from opaque_keys.edx.keys import CourseKey, UsageKey
+from ccx_keys.locator import CCXLocator, CCXBlockUsageLocator
+
+from .models import CcxMembership, CcxFieldOverride, CustomCourseForEdX
+
 
-from .models import CcxMembership, CcxFieldOverride
+log = logging.getLogger(__name__)
 
 
 class CustomCoursesForEdxOverrideProvider(FieldOverrideProvider):
@@ -25,43 +27,42 @@ class CustomCoursesForEdxOverrideProvider(FieldOverrideProvider):
         """
         Just call the get_override_for_ccx method if there is a ccx
         """
-        ccx = get_current_ccx()
+        # The incoming block might be a CourseKey instance of some type, a
+        # UsageKey instance of some type, or it might be something that has a
+        # location attribute.  That location attribute will be a UsageKey
+        ccx = course_id = None
+        identifier = getattr(block, 'id', None)
+        if isinstance(identifier, CourseKey):
+            course_id = block.id
+        elif isinstance(identifier, UsageKey):
+            course_id = block.id.course_key
+        elif hasattr(block, 'location'):
+            course_id = block.location.course_key
+        else:
+            msg = "Unable to get course id when calculating ccx overide for block type {}"
+            log.error(msg.format(type(block)))
+        if course_id is not None:
+            ccx = get_current_ccx(course_id)
         if ccx:
             return get_override_for_ccx(ccx, block, name, default)
         return default
 
 
-class _CcxContext(threading.local):
+def get_current_ccx(course_id):
     """
-    A threading local used to implement the `with_ccx` context manager, that
-    keeps track of the CCX currently set as the context.
+    Return the ccx that is active for this course.
     """
-    ccx = None
-    request = None
-
-
-_CCX_CONTEXT = _CcxContext()
-
-
-@contextmanager
-def ccx_context(ccx):
-    """
-    A context manager which can be used to explicitly set the CCX that is in
-    play for field overrides.  This mechanism overrides the standard mechanism
-    of looking in the user's session to see if they are enrolled in a CCX and
-    viewing that CCX.
-    """
-    prev = _CCX_CONTEXT.ccx
-    _CCX_CONTEXT.ccx = ccx
-    yield
-    _CCX_CONTEXT.ccx = prev
-
+    # ensure that the ID passed in is a CourseKey instance of some type.
+    if isinstance(course_id, CourseKey):
+        course_key = course_id
+    else:
+        course_key = CourseKey.from_string(course_id)
 
-def get_current_ccx():
-    """
-    Return the ccx that is active for this request.
-    """
-    return _CCX_CONTEXT.ccx
+    ccx = None
+    if isinstance(course_key, CCXLocator):
+        ccx_id = course_key.ccx
+        ccx = CustomCourseForEdX.objects.get(pk=ccx_id)
+    return ccx
 
 
 def get_override_for_ccx(ccx, block, name, default=None):
@@ -85,9 +86,14 @@ def _get_overrides_for_ccx(ccx, block):
     overrides set on this block for this CCX.
     """
     overrides = {}
+    # block as passed in may have a location specific to a CCX, we must strip
+    # that for this query
+    location = block.location
+    if isinstance(block.location, CCXBlockUsageLocator):
+        location = block.location.to_block_locator()
     query = CcxFieldOverride.objects.filter(
         ccx=ccx,
-        location=block.location
+        location=location
     )
     for override in query:
         field = block.fields[override.field]
@@ -141,35 +147,3 @@ def clear_override_for_ccx(ccx, block, name):
 
     except CcxFieldOverride.DoesNotExist:
         pass
-
-
-class CcxMiddleware(object):
-    """
-    Checks to see if current session is examining a CCX and sets the CCX as
-    the current CCX for the override machinery if so.
-    """
-    def process_request(self, request):
-        """
-        Do the check.
-        """
-        ccx_id = request.session.get(ACTIVE_CCX_KEY, None)
-        if ccx_id is not None:
-            try:
-                membership = CcxMembership.objects.get(
-                    student=request.user, active=True, ccx__id__exact=ccx_id
-                )
-                _CCX_CONTEXT.ccx = membership.ccx
-            except CcxMembership.DoesNotExist:
-                # if there is no membership, be sure to unset the active ccx
-                _CCX_CONTEXT.ccx = None
-                request.session.pop(ACTIVE_CCX_KEY)
-
-        _CCX_CONTEXT.request = request
-
-    def process_response(self, request, response):  # pylint: disable=unused-argument
-        """
-        Clean up afterwards.
-        """
-        _CCX_CONTEXT.ccx = None
-        _CCX_CONTEXT.request = None
-        return response

lms/djangoapps/ccx/tests/test_ccx_modulestore.py

+"""
+Test the CCXModulestoreWrapper
+"""
+from collections import deque
+from ccx_keys.locator import CCXLocator, CCXBlockUsageLocator
+import datetime
+from itertools import izip_longest
+import pytz
+from student.tests.factories import (  # pylint: disable=import-error
+    AdminFactory,
+    CourseEnrollmentFactory,
+    UserFactory,
+)
+from xmodule.modulestore.tests.django_utils import (
+    ModuleStoreTestCase,
+    TEST_DATA_SPLIT_MODULESTORE)
+from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory
+
+from ..models import CustomCourseForEdX
+
+
+def flatten(seq):
+    """
+    For [[1, 2], [3, 4]] returns [1, 2, 3, 4].  Does not recurse.
+    """
+    return [x for sub in seq for x in sub]
+
+
+class TestCCXModulestoreWrapper(ModuleStoreTestCase):
+    """tests for a modulestore wrapped by CCXModulestoreWrapper
+    """
+    MODULESTORE = TEST_DATA_SPLIT_MODULESTORE
+
+    def setUp(self):
+        """
+        Set up tests
+        """
+        super(TestCCXModulestoreWrapper, self).setUp()
+        course = CourseFactory.create()
+
+        # Create instructor account
+        coach = AdminFactory.create()
+
+        # Create a course outline
+        self.mooc_start = start = datetime.datetime(
+            2010, 5, 12, 2, 42, tzinfo=pytz.UTC)
+        self.mooc_due = due = datetime.datetime(
+            2010, 7, 7, 0, 0, tzinfo=pytz.UTC)
+        chapters = [ItemFactory.create(start=start, parent=course)
+                    for _ in xrange(2)]
+        sequentials = flatten([
+            [
+                ItemFactory.create(parent=chapter) for _ in xrange(2)
+            ] for chapter in chapters
+        ])
+        verticals = flatten([
+            [
+                ItemFactory.create(
+                    due=due, parent=sequential, graded=True, format='Homework'
+                ) for _ in xrange(2)
+            ] for sequential in sequentials
+        ])
+        blocks = flatten([  # pylint: disable=unused-variable
+            [
+                ItemFactory.create(parent=vertical) for _ in xrange(2)
+            ] for vertical in verticals
+        ])
+
+        self.ccx = ccx = CustomCourseForEdX(
+            course_id=course.id,
+            display_name='Test CCX',
+            coach=coach
+        )
+        ccx.save()
+
+        self.ccx_locator = CCXLocator.from_course_locator(course.id, ccx.id)
+
+    def get_all_children_bf(self, block):
+        queue = deque([block])
+        while queue:
+            item = queue.popleft()
+            yield item
+            queue.extend(item.get_children())
+
+    def get_course(self, key):
+        """get a course given a key"""
+        with self.store.bulk_operations(key):
+            course = self.store.get_course(key)
+        return course
+
+    def test_get_course(self):
+        """retrieving a course with a ccx key works"""
+        expected = self.get_course(self.ccx_locator.to_course_locator())
+        actual = self.get_course(self.ccx_locator)
+        self.assertEqual(
+            expected.location.course_key,
+            actual.location.course_key.to_course_locator())
+        self.assertEqual(expected.display_name, actual.display_name)
+
+    def test_get_children(self):
+        """the children of retrieved courses should be the same with course and ccx keys
+        """
+        course_key = self.ccx_locator.to_course_locator()
+        course = self.get_course(course_key)
+        ccx = self.get_course(self.ccx_locator)
+        for expected, actual in izip_longest(
+            self.get_all_children_bf(course), self.get_all_children_bf(ccx)
+        ):
+            if expected is None:
+                self.fail('course children exhausted before ccx children')
+            if actual is None:
+                self.fail('ccx children exhausted before course children')
+            self.assertEqual(expected.display_name, actual.display_name)
+            self.assertEqual(expected.location.course_key, course_key)
+            self.assertEqual(actual.location.course_key, self.ccx_locator)
+

lms/djangoapps/ccx/tests/test_overrides.py

@@ -9,7 +9,9 @@ from nose.plugins.attrib import attr
 from courseware.field_overrides import OverrideFieldData  # pylint: disable=import-error
 from django.test.utils import override_settings
 from student.tests.factories import AdminFactory  # pylint: disable=import-error
-from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
+from xmodule.modulestore.tests.django_utils import (
+    ModuleStoreTestCase,
+    TEST_DATA_SPLIT_MODULESTORE)
 from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory
 
 from ..models import CustomCourseForEdX
@@ -25,6 +27,7 @@ class TestFieldOverrides(ModuleStoreTestCase):
     """
     Make sure field overrides behave in the expected manner.
     """
+    MODULESTORE = TEST_DATA_SPLIT_MODULESTORE
     def setUp(self):
         """
         Set up tests
@@ -64,7 +67,7 @@ class TestFieldOverrides(ModuleStoreTestCase):
         # sure if there's a way to poke the test harness to do so.  So, we'll
         # just inject the override field storage in this brute force manner.
         OverrideFieldData.provider_classes = None
-        for block in iter_blocks(course):
+        for block in iter_blocks(ccx.course):
             block._field_data = OverrideFieldData.wrap(   # pylint: disable=protected-access
                 AdminFactory.create(), block._field_data)   # pylint: disable=protected-access
 
@@ -81,7 +84,7 @@ class TestFieldOverrides(ModuleStoreTestCase):
         Test that overriding start date on a chapter works.
         """
         ccx_start = datetime.datetime(2014, 12, 25, 00, 00, tzinfo=pytz.UTC)
-        chapter = self.course.get_children()[0]
+        chapter = self.ccx.course.get_children()[0]
         override_field_for_ccx(self.ccx, chapter, 'start', ccx_start)
         self.assertEquals(chapter.start, ccx_start)
 
@@ -90,7 +93,7 @@ class TestFieldOverrides(ModuleStoreTestCase):
         Test that overriding and accessing a field produce same number of queries.
         """
         ccx_start = datetime.datetime(2014, 12, 25, 00, 00, tzinfo=pytz.UTC)
-        chapter = self.course.get_children()[0]
+        chapter = self.ccx.course.get_children()[0]
         with self.assertNumQueries(4):
             override_field_for_ccx(self.ccx, chapter, 'start', ccx_start)
             dummy = chapter.start
@@ -100,7 +103,7 @@ class TestFieldOverrides(ModuleStoreTestCase):
         Test no extra queries when accessing an overriden field more than once.
         """
         ccx_start = datetime.datetime(2014, 12, 25, 00, 00, tzinfo=pytz.UTC)
-        chapter = self.course.get_children()[0]
+        chapter = self.ccx.course.get_children()[0]
         with self.assertNumQueries(4):
             override_field_for_ccx(self.ccx, chapter, 'start', ccx_start)
             dummy1 = chapter.start
@@ -112,7 +115,7 @@ class TestFieldOverrides(ModuleStoreTestCase):
         Test that sequentials inherit overridden start date from chapter.
         """
         ccx_start = datetime.datetime(2014, 12, 25, 00, 00, tzinfo=pytz.UTC)
-        chapter = self.course.get_children()[0]
+        chapter = self.ccx.course.get_children()[0]
         override_field_for_ccx(self.ccx, chapter, 'start', ccx_start)
         self.assertEquals(chapter.get_children()[0].start, ccx_start)
         self.assertEquals(chapter.get_children()[1].start, ccx_start)
@@ -124,7 +127,7 @@ class TestFieldOverrides(ModuleStoreTestCase):
         the mooc.
         """
         ccx_due = datetime.datetime(2015, 1, 1, 00, 00, tzinfo=pytz.UTC)
-        chapter = self.course.get_children()[0]
+        chapter = self.ccx.course.get_children()[0]
         chapter.display_name = 'itsme!'
         override_field_for_ccx(self.ccx, chapter, 'due', ccx_due)
         vertical = chapter.get_children()[0].get_children()[0]

lms/djangoapps/ccx/tests/test_utils.py

@@ -16,11 +16,12 @@ from student.roles import CourseCcxCoachRole  # pylint: disable=import-error
 from student.tests.factories import (  # pylint: disable=import-error
     AdminFactory,
     UserFactory,
-    CourseEnrollmentFactory,
-    AnonymousUserFactory,
 )
-from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
+from xmodule.modulestore.tests.django_utils import (
+    ModuleStoreTestCase,
+    TEST_DATA_SPLIT_MODULESTORE)
 from xmodule.modulestore.tests.factories import CourseFactory
+from ccx_keys.locator import CCXLocator
 
 
 @attr('shard_1')
@@ -128,6 +129,7 @@ class TestEmailEnrollmentState(ModuleStoreTestCase):
 class TestGetEmailParams(ModuleStoreTestCase):
     """tests for ccx.utils.get_email_params
     """
+    MODULESTORE = TEST_DATA_SPLIT_MODULESTORE
     def setUp(self):
         """
         Set up tests
@@ -157,7 +159,7 @@ class TestGetEmailParams(ModuleStoreTestCase):
         self.assertFalse(set(params.keys()) - set(self.all_keys))
 
     def test_ccx_id_in_params(self):
-        expected_course_id = self.ccx.course_id.to_deprecated_string()
+        expected_course_id = unicode(CCXLocator.from_course_locator(self.ccx.course_id, self.ccx.id))
         params = self.call_fut()
         self.assertEqual(params['course'], self.ccx)
         for url_key in self.url_keys:
@@ -185,6 +187,7 @@ class TestGetEmailParams(ModuleStoreTestCase):
 class TestEnrollEmail(ModuleStoreTestCase):
     """tests for the enroll_email function from ccx.utils
     """
+    MODULESTORE = TEST_DATA_SPLIT_MODULESTORE
     def setUp(self):
         super(TestEnrollEmail, self).setUp()
         # unbind the user created by the parent, so we can create our own when
@@ -365,6 +368,7 @@ class TestEnrollEmail(ModuleStoreTestCase):
 # TODO: deal with changes in behavior for auto_enroll
 class TestUnenrollEmail(ModuleStoreTestCase):
     """Tests for the unenroll_email function from ccx.utils"""
+    MODULESTORE = TEST_DATA_SPLIT_MODULESTORE
     def setUp(self):
         super(TestUnenrollEmail, self).setUp()
         # unbind the user created by the parent, so we can create our own when
@@ -508,70 +512,3 @@ class TestUnenrollEmail(ModuleStoreTestCase):
         self.check_enrollment_state(before, True, self.user, True)
         # no email was sent to the student
         self.assertEqual(self.outbox, [])
-
-
-@attr('shard_1')
-class TestUserCCXList(ModuleStoreTestCase):
-    """Unit tests for ccx.utils.get_all_ccx_for_user"""
-
-    def setUp(self):
-        """Create required infrastructure for tests"""
-        super(TestUserCCXList, self).setUp()
-        self.course = CourseFactory.create()
-        coach = AdminFactory.create()
-        role = CourseCcxCoachRole(self.course.id)
-        role.add_users(coach)
-        self.ccx = CcxFactory(course_id=self.course.id, coach=coach)
-        enrollment = CourseEnrollmentFactory.create(course_id=self.course.id)
-        self.user = enrollment.user
-        self.anonymous = AnonymousUserFactory.create()
-
-    def register_user_in_ccx(self, active=False):
-        """create registration of self.user in self.ccx
-
-        registration will be inactive unless active=True
-        """
-        CcxMembershipFactory(ccx=self.ccx, student=self.user, active=active)
-
-    def get_course_title(self):
-        """Get course title"""
-        from courseware.courses import get_course_about_section  # pylint: disable=import-error
-        return get_course_about_section(self.course, 'title')
-
-    def call_fut(self, user):
-        """Call function under test"""
-        from ccx.utils import get_all_ccx_for_user  # pylint: disable=import-error
-        return get_all_ccx_for_user(user)
-
-    def test_anonymous_sees_no_ccx(self):
-        memberships = self.call_fut(self.anonymous)
-        self.assertEqual(memberships, [])
-
-    def test_unenrolled_sees_no_ccx(self):
-        memberships = self.call_fut(self.user)
-        self.assertEqual(memberships, [])
-
-    def test_enrolled_inactive_sees_no_ccx(self):
-        self.register_user_in_ccx()
-        memberships = self.call_fut(self.user)
-        self.assertEqual(memberships, [])
-
-    def test_enrolled_sees_a_ccx(self):
-        self.register_user_in_ccx(active=True)
-        memberships = self.call_fut(self.user)
-        self.assertEqual(len(memberships), 1)
-
-    def test_data_structure(self):
-        self.register_user_in_ccx(active=True)
-        memberships = self.call_fut(self.user)
-        this_membership = memberships[0]
-        self.assertTrue(this_membership)
-        # structure contains the expected keys
-        for key in ['ccx_name', 'ccx_url']:
-            self.assertTrue(key in this_membership.keys())
-        url_parts = [self.course.id.to_deprecated_string(), str(self.ccx.id)]
-        # all parts of the ccx url are present
-        for part in url_parts:
-            self.assertTrue(part in this_membership['ccx_url'])
-        actual_name = self.ccx.display_name
-        self.assertEqual(actual_name, this_membership['ccx_name'])

lms/djangoapps/ccx/urls.py

@@ -24,6 +24,4 @@ urlpatterns = patterns(
         'ccx.views.ccx_grades_csv', name='ccx_grades_csv'),
     url(r'^ccx_set_grading_policy$',
         'ccx.views.set_grading_policy', name='ccx_set_grading_policy'),
-    url(r'^switch_ccx(?:/(?P<ccx_id>[\d]+))?$',
-        'ccx.views.switch_active_ccx', name='switch_active_ccx'),
 )

lms/djangoapps/ccx/utils.py

@@ -14,6 +14,7 @@ from edxmako.shortcuts import render_to_string  # pylint: disable=import-error
 from microsite_configuration import microsite  # pylint: disable=import-error
 from xmodule.modulestore.django import modulestore
 from xmodule.error_module import ErrorDescriptor
+from ccx_keys.locator import CCXLocator
 
 from .models import (
     CcxMembership,
@@ -138,7 +139,6 @@ def get_email_params(ccx, auto_enroll, secure=True):
     get parameters for enrollment emails
     """
     protocol = 'https' if secure else 'http'
-    course_id = ccx.course_id
 
     stripped_site_name = microsite.get_value(
         'SITE_NAME',
@@ -154,7 +154,7 @@ def get_email_params(ccx, auto_enroll, secure=True):
         site=stripped_site_name,
         path=reverse(
             'course_root',
-            kwargs={'course_id': course_id.to_deprecated_string()}
+            kwargs={'course_id':  CCXLocator.from_course_locator(ccx.course_id, ccx.id)}
         )
     )
 
@@ -165,7 +165,7 @@ def get_email_params(ccx, auto_enroll, secure=True):
             site=stripped_site_name,
             path=reverse(
                 'about_course',
-                kwargs={'course_id': course_id.to_deprecated_string()}
+                kwargs={'course_id':  CCXLocator.from_course_locator(ccx.course_id, ccx.id)}
             )
         )
 
@@ -241,44 +241,6 @@ def send_mail_to_student(student, param_dict):
         )
 
 
-def get_all_ccx_for_user(user):
-    """return all CCXS to which the user is registered
-
-    Returns a list of dicts: {
-        ccx_name: <formatted title of CCX course>
-        ccx_url: <url to view this CCX>
-        ccx_active: True if this ccx is currently the 'active' one
-        mooc_name: <formatted title of the MOOC course for this CCX>
-        mooc_url: <url to view this MOOC>
-    }
-    """
-    if user.is_anonymous():
-        return []
-    current_active_ccx = get_current_ccx()
-    memberships = []
-    for membership in CcxMembership.memberships_for_user(user):
-        course = get_course_by_id(membership.ccx.course_id)
-        ccx = membership.ccx
-        ccx_title = ccx.display_name
-        mooc_title = get_course_about_section(course, 'title')
-        url = reverse(
-            'switch_active_ccx',
-            args=[course.id.to_deprecated_string(), membership.ccx.id]
-        )
-        mooc_url = reverse(
-            'switch_active_ccx',
-            args=[course.id.to_deprecated_string(), ]
-        )
-        memberships.append({
-            'ccx_name': ccx_title,
-            'ccx_url': url,
-            'active': membership.ccx == current_active_ccx,
-            'mooc_name': mooc_title,
-            'mooc_url': mooc_url,
-        })
-    return memberships
-
-
 def get_ccx_membership_triplets(user, course_org_filter, org_filter_out_set):
     """
     Get the relevant set of (CustomCourseForEdX, CcxMembership, Course)

lms/djangoapps/ccx/views.py

@@ -8,6 +8,7 @@ import json
 import logging
 import pytz
 
+from contextlib import contextmanager
 from copy import deepcopy
 from cStringIO import StringIO
 
@@ -19,6 +20,7 @@ from django.http import (
 )
 from django.core.exceptions import ValidationError
 from django.core.validators import validate_email
+from django.http import Http404
 from django.shortcuts import redirect
 from django.utils.translation import ugettext as _
 from django.views.decorators.cache import cache_control
@@ -34,6 +36,7 @@ from courseware.model_data import FieldDataCache  # pylint: disable=import-error
 from courseware.module_render import get_module_for_descriptor  # pylint: disable=import-error
 from edxmako.shortcuts import render_to_response  # pylint: disable=import-error
 from opaque_keys.edx.keys import CourseKey
+from ccx_keys.locator import CCXLocator
 from student.roles import CourseCcxCoachRole  # pylint: disable=import-error
 
 from instructor.offline_gradecalc import student_grades  # pylint: disable=import-error
@@ -45,13 +48,11 @@ from .overrides import (
     clear_override_for_ccx,
     get_override_for_ccx,
     override_field_for_ccx,
-    ccx_context,
 )
 from .utils import (
     enroll_email,
     unenroll_email,
 )
-from ccx import ACTIVE_CCX_KEY  # pylint: disable=import-error
 
 
 log = logging.getLogger(__name__)
@@ -71,43 +72,60 @@ def coach_dashboard(view):
         and modifying the view's call signature.
         """
         course_key = CourseKey.from_string(course_id)
+        ccx = None
+        if isinstance(course_key, CCXLocator):
+            # is there a security leak here in not checking that this user is
+            # the coach for this ccx?
+            ccx_id = course_key.ccx
+            ccx = CustomCourseForEdX.objects.get(pk=ccx_id)
+            course_key = ccx.course_id
+
         role = CourseCcxCoachRole(course_key)
         if not role.has_user(request.user):
             return HttpResponseForbidden(
                 _('You must be a CCX Coach to access this view.'))
+
         course = get_course_by_id(course_key, depth=None)
-        return view(request, course)
+        return view(request, course, ccx)
     return wrapper
 
 
 @ensure_csrf_cookie
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @coach_dashboard
-def dashboard(request, course):
+def dashboard(request, course, ccx=None):
     """
     Display the CCX Coach Dashboard.
     """
-    ccx = get_ccx_for_coach(course, request.user)
+    # right now, we can only have one ccx per user and course
+    # so, if no ccx is passed in, we can sefely redirect to that
+    if ccx is None:
+        ccx = get_ccx_for_coach(course, request.user)
+        if ccx:
+            url = reverse('ccx_coach_dashboard', kwargs={'course_id': CCXLocator.from_course_locator(course.id, ccx.id)})
+            return redirect(url)
+
     context = {
         'course': course,
         'ccx': ccx,
     }
 
     if ccx:
+        ccx_locator = CCXLocator.from_course_locator(course.id, ccx.id)
         schedule = get_ccx_schedule(course, ccx)
         grading_policy = get_override_for_ccx(
             ccx, course, 'grading_policy', course.grading_policy)
         context['schedule'] = json.dumps(schedule, indent=4)
         context['save_url'] = reverse(
-            'save_ccx', kwargs={'course_id': course.id})
+            'save_ccx', kwargs={'course_id': ccx_locator})
         context['ccx_members'] = CcxMembership.objects.filter(ccx=ccx)
         context['gradebook_url'] = reverse(
-            'ccx_gradebook', kwargs={'course_id': course.id})
+            'ccx_gradebook', kwargs={'course_id': ccx_locator})
         context['grades_csv_url'] = reverse(
-            'ccx_grades_csv', kwargs={'course_id': course.id})
+            'ccx_grades_csv', kwargs={'course_id': ccx_locator})
         context['grading_policy'] = json.dumps(grading_policy, indent=4)
         context['grading_policy_url'] = reverse(
-            'ccx_set_grading_policy', kwargs={'course_id': course.id})
+            'ccx_set_grading_policy', kwargs={'course_id': ccx_locator})
     else:
         context['create_ccx_url'] = reverse(
             'create_ccx', kwargs={'course_id': course.id})
@@ -117,7 +135,7 @@ def dashboard(request, course):
 @ensure_csrf_cookie
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @coach_dashboard
-def create_ccx(request, course):
+def create_ccx(request, course, ccx=None):
     """
     Create a new CCX
     """
@@ -142,18 +160,20 @@ def create_ccx(request, course):
             for vertical in sequential.get_children():
                 override_field_for_ccx(ccx, vertical, hidden, True)
 
-    url = reverse('ccx_coach_dashboard', kwargs={'course_id': course.id})
+    ccx_id = CCXLocator.from_course_locator(course.id, ccx.id)
+    url = reverse('ccx_coach_dashboard', kwargs={'course_id': ccx_id})
     return redirect(url)
 
 
 @ensure_csrf_cookie
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @coach_dashboard
-def save_ccx(request, course):
+def save_ccx(request, course, ccx=None):
     """
     Save changes to CCX.
     """
-    ccx = get_ccx_for_coach(course, request.user)
+    if not ccx:
+        raise Http404
 
     def override_fields(parent, data, graded, earliest=None):
         """
@@ -220,15 +240,20 @@ def save_ccx(request, course):
 @ensure_csrf_cookie
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @coach_dashboard
-def set_grading_policy(request, course):
+def set_grading_policy(request, course, ccx=None):
     """
     Set grading policy for the CCX.
     """
-    ccx = get_ccx_for_coach(course, request.user)
+    if not ccx:
+        raise Http404
+
     override_field_for_ccx(
         ccx, course, 'grading_policy', json.loads(request.POST['policy']))
 
-    url = reverse('ccx_coach_dashboard', kwargs={'course_id': course.id})
+    url = reverse(
+        'ccx_coach_dashboard',
+        kwargs={'course_id': CCXLocator.from_course_locator(course.id, ccx.id)}
+    )
     return redirect(url)
 
 
@@ -271,12 +296,15 @@ def get_ccx_for_coach(course, coach):
     Looks to see if user is coach of a CCX for this course.  Returns the CCX or
     None.
     """
-    try:
-        return CustomCourseForEdX.objects.get(
-            course_id=course.id,
-            coach=coach)
-    except CustomCourseForEdX.DoesNotExist:
-        return None
+    ccxs = CustomCourseForEdX.objects.filter(
+        course_id=course.id,
+        coach=coach
+    )
+    # XXX: In the future, it would be nice to support more than one ccx per
+    # coach per course.  This is a place where that might happen.
+    if ccxs.exists():
+        return ccxs[0]
+    return None
 
 
 def get_ccx_schedule(course, ccx):
@@ -322,11 +350,13 @@ def get_ccx_schedule(course, ccx):
 @ensure_csrf_cookie
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @coach_dashboard
-def ccx_schedule(request, course):
+def ccx_schedule(request, course, ccx=None):
     """
     get json representation of ccx schedule
     """
-    ccx = get_ccx_for_coach(course, request.user)
+    if not ccx:
+        raise Http404
+
     schedule = get_ccx_schedule(course, ccx)
     json_schedule = json.dumps(schedule, indent=4)
     return HttpResponse(json_schedule, mimetype='application/json')
@@ -335,11 +365,13 @@ def ccx_schedule(request, course):
 @ensure_csrf_cookie
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @coach_dashboard
-def ccx_invite(request, course):
+def ccx_invite(request, course, ccx=None):
     """
     Invite users to new ccx
     """
-    ccx = get_ccx_for_coach(course, request.user)
+    if not ccx:
+        raise Http404
+
     action = request.POST.get('enrollment-button')
     identifiers_raw = request.POST.get('student-ids')
     identifiers = _split_input_list(identifiers_raw)
@@ -367,17 +399,22 @@ def ccx_invite(request, course):
                 unenroll_email(ccx, email, email_students=email_students)
         except ValidationError:
             log.info('Invalid user name or email when trying to invite students: %s', email)
-    url = reverse('ccx_coach_dashboard', kwargs={'course_id': course.id})
+    url = reverse(
+        'ccx_coach_dashboard',
+        kwargs={'course_id': CCXLocator.from_course_locator(course.id, ccx.id)}
+    )
     return redirect(url)
 
 
 @ensure_csrf_cookie
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @coach_dashboard
-def ccx_student_management(request, course):
+def ccx_student_management(request, course, ccx=None):
     """Manage the enrollment of individual students in a CCX
     """
-    ccx = get_ccx_for_coach(course, request.user)
+    if not ccx:
+        raise Http404
+
     action = request.POST.get('student-action', None)
     student_id = request.POST.get('student-id', '')
     user = email = None
@@ -399,28 +436,42 @@ def ccx_student_management(request, course):
     except ValidationError:
         log.info('Invalid user name or email when trying to enroll student: %s', email)
 
-    url = reverse('ccx_coach_dashboard', kwargs={'course_id': course.id})
+    url = reverse(
+        'ccx_coach_dashboard',
+        kwargs={'course_id': CCXLocator.from_course_locator(course.id, ccx.id)}
+    )
     return redirect(url)
 
 
+@contextmanager
+def ccx_course(ccx_locator):
+    course = get_course_by_id(ccx_locator)
+    yield course
+
+
+def prep_course_for_grading(course, request):
+    """Set up course module for overrides to function properly"""
+    field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
+        course.id, request.user, course, depth=2)
+    course = get_module_for_descriptor(
+        request.user, request, course, field_data_cache, course.id)
+
+    course._field_data_cache = {}  # pylint: disable=protected-access
+    course.set_grading_policy(course.grading_policy)
+
+
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @coach_dashboard
-def ccx_gradebook(request, course):
+def ccx_gradebook(request, course, ccx=None):
     """
     Show the gradebook for this CCX.
     """
-    # Need course module for overrides to function properly
-    field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
-        course.id, request.user, course, depth=2)
-    course = get_module_for_descriptor(
-        request.user, request, course, field_data_cache, course.id)
+    if not ccx:
+        raise Http404
 
-    ccx = get_ccx_for_coach(course, request.user)
-    with ccx_context(ccx):
-        # The grading policy for the MOOC is probably already cached.  We need
-        # to make sure we have the CCX grading policy loaded.
-        course._field_data_cache = {}  # pylint: disable=protected-access
-        course.set_grading_policy(course.grading_policy)
+    ccx_key = CCXLocator.from_course_locator(course.id, ccx.id)
+    with ccx_course(ccx_key) as course:
+        prep_course_for_grading(course, request)
 
         enrolled_students = User.objects.filter(
             ccxmembership__ccx=ccx,
@@ -450,21 +501,16 @@ def ccx_gradebook(request, course):
 
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @coach_dashboard
-def ccx_grades_csv(request, course):
+def ccx_grades_csv(request, course, ccx=None):
     """
     Download grades as CSV.
     """
-    # Need course module for overrides to function properly
-    field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
-        course.id, request.user, course, depth=2)
-    course = get_module_for_descriptor(
-        request.user, request, course, field_data_cache, course.id)
-    ccx = get_ccx_for_coach(course, request.user)
-    with ccx_context(ccx):
-        # The grading policy for the MOOC is probably already cached.  We need
-        # to make sure we have the CCX grading policy loaded.
-        course._field_data_cache = {}  # pylint: disable=protected-access
-        course.set_grading_policy(course.grading_policy)
+    if not ccx:
+        raise Http404
+
+    ccx_key = CCXLocator.from_course_locator(course.id, ccx.id)
+    with ccx_course(ccx_key) as course:
+        prep_course_for_grading(course, request)
 
         enrolled_students = User.objects.filter(
             ccxmembership__ccx=ccx,
@@ -501,33 +547,3 @@ def ccx_grades_csv(request, course):
             writer.writerow(row)
 
         return HttpResponse(buf.getvalue(), content_type='text/plain')
-
-
-@login_required
-def switch_active_ccx(request, course_id, ccx_id=None):
-    """set the active CCX for the logged-in user
-    """
-    course_key = CourseKey.from_string(course_id)
-    # will raise Http404 if course_id is bad
-    course = get_course_by_id(course_key)
-    course_url = reverse(
-        'course_root', args=[course.id.to_deprecated_string()]
-    )
-    if ccx_id is not None:
-        try:
-            requested_ccx = CustomCourseForEdX.objects.get(pk=ccx_id)
-            assert unicode(requested_ccx.course_id) == course_id
-            if not CcxMembership.objects.filter(
-                    ccx=requested_ccx, student=request.user, active=True
-            ).exists():
-                ccx_id = None
-        except CustomCourseForEdX.DoesNotExist:
-            # what to do here?  Log the failure?  Do we care?
-            ccx_id = None
-        except AssertionError:
-            # what to do here?  Log the failure?  Do we care?
-            ccx_id = None
-
-    request.session[ACTIVE_CCX_KEY] = ccx_id
-
-    return HttpResponseRedirect(course_url)

lms/djangoapps/courseware/access.py

@@ -43,6 +43,7 @@ from util.milestones_helpers import (
     get_pre_requisite_courses_not_completed,
     any_unfulfilled_milestones,
 )
+from ccx_keys.locator import CCXLocator
 
 import dogstats_wrapper as dog_stats_api
 
@@ -91,6 +92,9 @@ def has_access(user, action, obj, course_key=None):
     if not user:
         user = AnonymousUser()
 
+    if isinstance(course_key, CCXLocator):
+        course_key = course_key.to_course_locator()
+
     # delegate the work to type-specific functions.
     # (start with more specific types, then get more general)
     if isinstance(obj, CourseDescriptor):
@@ -107,6 +111,8 @@ def has_access(user, action, obj, course_key=None):
         return _has_access_descriptor(user, action, obj, course_key)
 
     if isinstance(obj, CourseKey):
+        if isinstance(obj, CCXLocator):
+            obj = obj.to_course_locator()
         return _has_access_course_key(user, action, obj)
 
     if isinstance(obj, UsageKey):

lms/djangoapps/django_comment_client/forum/views.py

@@ -65,7 +65,7 @@ class DiscussionTab(EnrolledTab):
             return False
 
         if settings.FEATURES.get('CUSTOM_COURSES_EDX', False):
-            if get_current_ccx():
+            if get_current_ccx(course.id):
                 return False
         return settings.FEATURES.get('ENABLE_DISCUSSION_SERVICE')
 

lms/envs/test.py

@@ -473,7 +473,6 @@ FEATURES['CERTIFICATES_HTML_VIEW'] = True
 
 ######### custom courses #########
 INSTALLED_APPS += ('ccx',)
-MIDDLEWARE_CLASSES += ('ccx.overrides.CcxMiddleware',)
 FEATURES['CUSTOM_COURSES_EDX'] = True
 
 # Set dummy values for profile image settings.

lms/templates/ccx/_dashboard_ccx_listing.html

@@ -4,9 +4,10 @@
 from django.utils.translation import ugettext as _
 from django.core.urlresolvers import reverse
 from courseware.courses import course_image_url, get_course_about_section
+from ccx_keys.locator import CCXLocator
 %>
 <%
-  ccx_switch_target = reverse('switch_active_ccx', args=[course.id.to_deprecated_string(), ccx.id])
+  ccx_target = reverse('info', args=[CCXLocator.from_course_locator(course.id, ccx.id)])
 %>
 <li class="course-item">
   <article class="course">
@@ -14,7 +15,7 @@ from courseware.courses import course_image_url, get_course_about_section
       <div class="wrapper-course-image" aria-hidden="true">
         % if show_courseware_link:
           % if not is_course_blocked:
-              <a href="${ccx_switch_target}" class="cover">
+              <a href="${ccx_target}" class="cover">
                 <img src="${course_image_url(course)}" class="course-image" alt="${_('{course_number} {ccx_name} Cover Image').format(course_number=course.number, ccx_name=ccx.display_name) |h}" />
               </a>
           % else:
@@ -32,7 +33,7 @@ from courseware.courses import course_image_url, get_course_about_section
         <h3 class="course-title">
           % if show_courseware_link:
             % if not is_course_blocked:
-              <a href="${ccx_switch_target}">${ccx.display_name}</a>
+              <a href="${ccx_target}">${ccx.display_name}</a>
             % else:
               <a class="disable-look">${ccx.display_name}</a>
             % endif
@@ -58,13 +59,13 @@ from courseware.courses import course_image_url, get_course_about_section
             <div class="course-actions">
               % if ccx.has_ended():
                 % if not is_course_blocked:
-                  <a href="${ccx_switch_target}" class="enter-course archived">${_('View Archived Custom Course')}<span class="sr">&nbsp;${ccx.display_name}</span></a>
+                  <a href="${ccx_target}" class="enter-course archived">${_('View Archived Custom Course')}<span class="sr">&nbsp;${ccx.display_name}</span></a>
                 % else:
                   <a class="enter-course-blocked archived">${_('View Archived Custom Course')}<span class="sr">&nbsp;${ccx.display_name}</span></a>
                 % endif
               % else:
                 % if not is_course_blocked:
-                  <a href="${ccx_switch_target}" class="enter-course">${_('View Custom Course')}<span class="sr">&nbsp;${ccx.display_name}</span></a>
+                  <a href="${ccx_target}" class="enter-course">${_('View Custom Course')}<span class="sr">&nbsp;${ccx.display_name}</span></a>
                 % else:
                   <a class="enter-course-blocked">${_('View Custom Course')}<span class="sr">&nbsp;${ccx.display_name}</span></a>
                 % endif

lms/templates/navigation.html

@@ -53,7 +53,7 @@ site_status_msg = get_site_status_msg(course_id)
       <%
         display_name = course.display_name_with_default
         if settings.FEATURES.get('CUSTOM_COURSES_EDX', False):
-          ccx = get_current_ccx()
+          ccx = get_current_ccx(course.id)
           if ccx:
             display_name = ccx.display_name
       %>

requirements/edx/github.txt

@@ -54,6 +54,7 @@ git+https://github.com/edx/edx-lint.git@ed8c8d2a0267d4d42f43642d193e25f8bd575d9b
 -e git+https://github.com/edx-solutions/xblock-google-drive.git@138e6fa0bf3a2013e904a085b9fed77dab7f3f21#egg=xblock-google-drive
 -e git+https://github.com/edx/edx-reverification-block.git@6e2834c5f7e998ad9b81170e7ceb4d8a64900eb0#egg=edx-reverification-block
 git+https://github.com/edx/ecommerce-api-client.git@1.0.0#egg=ecommerce-api-client==1.0.0
+-e git+https://github.com/jazkarta/ccx-keys.git@e6b03704b1bb97c1d2f31301ecb4e3a687c536ea#egg=ccx-keys
 
 # Third Party XBlocks
 -e git+https://github.com/mitodl/edx-sga@172a90fd2738f8142c10478356b2d9ed3e55334a#egg=edx-sga