Allow LMS to do forum thread response pagination

The relevant parameters and data are merely passed through between the
front end and comments service.

lms/djangoapps/django_comment_client/forum/tests.py

@@ -11,7 +11,7 @@ from django_comment_client.forum import views
 
 from courseware.tests.modulestore_config import TEST_DATA_MIXED_MODULESTORE
 from nose.tools import assert_true  # pylint: disable=E0611
-from mock import patch, Mock
+from mock import patch, Mock, ANY
 
 import logging
 
@@ -85,6 +85,26 @@ class ViewsExceptionTestCase(UrlResetMixin, ModuleStoreTestCase):
         self.assertEqual(self.response.status_code, 404)
 
 
+def make_mock_thread_data(text, thread_id, include_children):
+    thread_data = {
+        "id": thread_id,
+        "type": "thread",
+        "title": text,
+        "body": text,
+        "commentable_id": "dummy_commentable_id",
+        "resp_total": 42,
+        "resp_skip": 25,
+        "resp_limit": 5,
+    }
+    if include_children:
+        thread_data["children"] = [{
+            "id": "dummy_comment_id",
+            "type": "comment",
+            "body": text,
+        }]
+    return thread_data
+
+
 def make_mock_request_impl(text, thread_id=None):
     def mock_request_impl(*args, **kwargs):
         url = args[1]
@@ -92,30 +112,13 @@ def make_mock_request_impl(text, thread_id=None):
             return Mock(
                 status_code=200,
                 text=json.dumps({
-                    "collection": [{
-                        "id": "dummy_thread_id",
-                        "type": "thread",
-                        "commentable_id": "dummy_commentable_id",
-                        "title": text,
-                        "body": text,
-                    }]
+                    "collection": [make_mock_thread_data(text, "dummy_thread_id", False)]
                 })
             )
         elif thread_id and url.endswith(thread_id):
             return Mock(
                 status_code=200,
-                text=json.dumps({
-                    "id": thread_id,
-                    "type": "thread",
-                    "title": text,
-                    "body": text,
-                    "commentable_id": "dummy_commentable_id",
-                    "children": [{
-                        "id": "dummy_comment_id",
-                        "type": "comment",
-                        "body": text,
-                    }],
-                })
+                text=json.dumps(make_mock_thread_data(text, thread_id, True))
             )
         else: # user query
             return Mock(
@@ -129,6 +132,116 @@ def make_mock_request_impl(text, thread_id=None):
     return mock_request_impl
 
 
+class StringEndsWithMatcher(object):
+    def __init__(self, suffix):
+        self.suffix = suffix
+
+    def __eq__(self, other):
+        return other.endswith(self.suffix)
+
+
+class PartialDictMatcher(object):
+    def __init__(self, expected_values):
+        self.expected_values = expected_values
+
+    def __eq__(self, other):
+        return all([
+            key in other and other[key] == value
+            for key, value in self.expected_values.iteritems()
+        ])
+
+
+@override_settings(MODULESTORE=TEST_DATA_MIXED_MODULESTORE)
+@patch('requests.request')
+class SingleThreadTestCase(ModuleStoreTestCase):
+    def setUp(self):
+        self.course = CourseFactory.create()
+        self.student = UserFactory.create()
+        CourseEnrollmentFactory.create(user=self.student, course_id=self.course.id)
+
+    def test_ajax(self, mock_request):
+        text = "dummy content"
+        thread_id = "test_thread_id"
+        mock_request.side_effect = make_mock_request_impl(text, thread_id)
+
+        request = RequestFactory().get(
+            "dummy_url",
+            HTTP_X_REQUESTED_WITH="XMLHttpRequest"
+        )
+        request.user = self.student
+        response = views.single_thread(
+            request,
+            self.course.id,
+            "dummy_discussion_id",
+            "test_thread_id"
+        )
+
+        self.assertEquals(response.status_code, 200)
+        response_data = json.loads(response.content)
+        self.assertEquals(
+            response_data["content"],
+            make_mock_thread_data(text, thread_id, True)
+        )
+        mock_request.assert_called_with(
+            "get",
+            StringEndsWithMatcher(thread_id), # url
+            data=None,
+            params=PartialDictMatcher({"mark_as_read": True, "user_id": 1, "recursive": True}),
+            headers=ANY,
+            timeout=ANY
+        )
+
+    def test_skip_limit(self, mock_request):
+        text = "dummy content"
+        thread_id = "test_thread_id"
+        response_skip = "45"
+        response_limit = "15"
+        mock_request.side_effect = make_mock_request_impl(text, thread_id)
+
+        request = RequestFactory().get(
+            "dummy_url",
+            {"resp_skip": response_skip, "resp_limit": response_limit},
+            HTTP_X_REQUESTED_WITH="XMLHttpRequest"
+        )
+        request.user = self.student
+        response = views.single_thread(
+            request,
+            self.course.id,
+            "dummy_discussion_id",
+            "test_thread_id"
+        )
+        self.assertEquals(response.status_code, 200)
+        response_data = json.loads(response.content)
+        self.assertEquals(
+            response_data["content"],
+            make_mock_thread_data(text, thread_id, True)
+        )
+        mock_request.assert_called_with(
+            "get",
+            StringEndsWithMatcher(thread_id), # url
+            data=None,
+            params=PartialDictMatcher({
+                "mark_as_read": True,
+                "user_id": 1,
+                "recursive": True,
+                "resp_skip": response_skip,
+                "resp_limit": response_limit,
+            }),
+            headers=ANY,
+            timeout=ANY
+        )
+
+    def test_post(self, mock_request):
+        request = RequestFactory().post("dummy_url")
+        response = views.single_thread(
+            request,
+            self.course.id,
+            "dummy_discussion_id",
+            "dummy_thread_id"
+        )
+        self.assertEquals(response.status_code, 405)
+
+
 @override_settings(MODULESTORE=TEST_DATA_MIXED_MODULESTORE)
 class InlineDiscussionUnicodeTestCase(ModuleStoreTestCase, UnicodeTestMixin):
     def setUp(self):

lms/djangoapps/django_comment_client/forum/views.py

@@ -6,6 +6,7 @@ from django.contrib.auth.decorators import login_required
 from django.http import Http404
 from django.core.context_processors import csrf
 from django.contrib.auth.models import User
+from django.views.decorators.http import require_GET
 import newrelic.agent
 
 from edxmako.shortcuts import render_to_response
@@ -229,6 +230,7 @@ def forum_form_discussion(request, course_id):
         return render_to_response('discussion/index.html', context)
 
 
+@require_GET
 @login_required
 def single_thread(request, course_id, discussion_id, thread_id):
     nr_transaction = newrelic.agent.current_transaction()
@@ -237,12 +239,16 @@ def single_thread(request, course_id, discussion_id, thread_id):
     cc_user = cc.User.from_django_user(request.user)
     user_info = cc_user.to_dict()
 
-    thread = cc.Thread.find(thread_id).retrieve(recursive=True, user_id=request.user.id)
+    thread = cc.Thread.find(thread_id).retrieve(
+        recursive=True,
+        user_id=request.user.id,
+        response_skip=request.GET.get("resp_skip"),
+        response_limit=request.GET.get("resp_limit")
+    )
 
     if request.is_ajax():
         with newrelic.agent.FunctionTrace(nr_transaction, "get_annotated_content_infos"):
             annotated_content_info = utils.get_annotated_content_infos(course_id, thread, request.user, user_info=user_info)
-        context = {'thread': thread.to_dict(), 'course_id': course_id}
         content = utils.safe_content(thread.to_dict())
         with newrelic.agent.FunctionTrace(nr_transaction, "add_courseware_context"):
             add_courseware_context([content], course)

lms/djangoapps/django_comment_client/utils.py

@@ -362,7 +362,7 @@ def safe_content(content):
         'at_position_list', 'children', 'highlighted_title', 'highlighted_body',
         'courseware_title', 'courseware_url', 'unread_comments_count',
         'read', 'group_id', 'group_name', 'group_string', 'pinned', 'abuse_flaggers',
-        'stats'
+        'stats', 'resp_skip', 'resp_limit', 'resp_total',
 
     ]
 

lms/lib/comment_client/thread.py

@@ -74,10 +74,9 @@ class Thread(models.Model):
             'recursive': kwargs.get('recursive'),
             'user_id': kwargs.get('user_id'),
             'mark_as_read': kwargs.get('mark_as_read', True),
+            'resp_skip': kwargs.get('response_skip'),
+            'resp_limit': kwargs.get('response_limit'),
         }
-
-        # user_id may be none, in which case it shouldn't be part of the
-        # request.
         request_params = strip_none(request_params)
 
         response = perform_request('get', url, request_params)