Update comments app

Add transaction handling. Add comment view link. Update views to
user ExternalObjectMixin. Add event tests.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/document_comments/tests/test_events.py

@@ -0,0 +1,79 @@
+from __future__ import unicode_literals
+
+from actstream.models import Action
+
+from mayan.apps.documents.tests import GenericDocumentViewTestCase
+
+from ..events import (
+    event_document_comment_created, event_document_comment_deleted
+)
+from ..models import Comment
+from ..permissions import (
+    permission_document_comment_create, permission_document_comment_delete
+)
+
+from .mixins import DocumentCommentTestMixin, DocumentCommentViewTestMixin
+
+
+class CommentEventsTestCase(
+    DocumentCommentTestMixin, DocumentCommentViewTestMixin,
+    GenericDocumentViewTestCase
+):
+    def test_comment_create_event_no_permissions(self):
+        action_count = Action.objects.count()
+
+        response = self._request_test_comment_create_view()
+        self.assertEqual(response.status_code, 404)
+
+        self.assertEqual(Action.objects.count(), action_count)
+
+    def test_comment_create_event_with_permissions(self):
+        self.grant_permission(permission=permission_document_comment_create)
+
+        action_count = Action.objects.count()
+
+        response = self._request_test_comment_create_view()
+        self.assertEqual(response.status_code, 302)
+
+        self.assertEqual(Action.objects.count(), action_count + 1)
+
+        event = Action.objects.first()
+
+        comment = Comment.objects.first()
+
+        self.assertEqual(event.action_object, comment)
+        self.assertEqual(event.actor, self._test_case_user)
+        self.assertEqual(event.target, self.test_document)
+        self.assertEqual(event.verb, event_document_comment_created.id)
+
+    def test_comment_delete_event_no_permissions(self):
+        self._create_test_comment()
+
+        action_count = Action.objects.count()
+
+        response = self._request_test_comment_delete_view()
+        self.assertEqual(response.status_code, 404)
+
+        self.assertEqual(Action.objects.count(), action_count)
+
+    def test_comment_delete_event_with_access(self):
+        self._create_test_comment()
+
+        self.grant_access(
+            obj=self.test_document,
+            permission=permission_document_comment_delete
+        )
+
+        action_count = Action.objects.count()
+
+        response = self._request_test_comment_delete_view()
+        self.assertEqual(response.status_code, 302)
+        # Total count remains the same. Document comment created is removed due
+        # to cascade delete, document comment deleted event is added.
+        self.assertEqual(Action.objects.count(), action_count)
+
+        event = Action.objects.first()
+
+        self.assertEqual(event.actor, self._test_case_user)
+        self.assertEqual(event.target, self.test_document)
+        self.assertEqual(event.verb, event_document_comment_deleted.id)