Files
edx-platform/lms/djangoapps/discussion_api/api.py
Greg Price 5318f21e77 Merge pull request #8485 from edx/gprice/discussion-api-endorse
Add comment endorsement to discussion API
2015-06-15 17:10:05 -04:00

571 lines
19 KiB
Python

"""
Discussion API internal interface
"""
from collections import defaultdict
from urllib import urlencode
from urlparse import urlunparse
from django.core.exceptions import ValidationError
from django.core.urlresolvers import reverse
from django.http import Http404
from rest_framework.exceptions import PermissionDenied
from opaque_keys import InvalidKeyError
from opaque_keys.edx.locator import CourseKey
from courseware.courses import get_course_with_access
from discussion_api.forms import ThreadActionsForm
from discussion_api.pagination import get_paginated_data
from discussion_api.serializers import CommentSerializer, ThreadSerializer, get_context
from django_comment_client.base.views import (
THREAD_CREATED_EVENT_NAME,
get_comment_created_event_data,
get_comment_created_event_name,
get_thread_created_event_data,
track_forum_event,
)
from django_comment_client.utils import get_accessible_discussion_modules
from lms.lib.comment_client.comment import Comment
from lms.lib.comment_client.thread import Thread
from lms.lib.comment_client.utils import CommentClientRequestError
from openedx.core.djangoapps.course_groups.cohorts import get_cohort_id, is_commentable_cohorted
def _get_course_or_404(course_key, user):
"""
Get the course descriptor, raising Http404 if the course is not found,
the user cannot access forums for the course, or the discussion tab is
disabled for the course.
"""
course = get_course_with_access(user, 'load', course_key, check_if_enrolled=True)
if not any([tab.type == 'discussion' for tab in course.tabs]):
raise Http404
return course
def _get_thread_and_context(request, thread_id, retrieve_kwargs=None):
"""
Retrieve the given thread and build a serializer context for it, returning
both. This function also enforces access control for the thread (checking
both the user's access to the course and to the thread's cohort if
applicable). Raises Http404 if the thread does not exist or the user cannot
access it.
"""
retrieve_kwargs = retrieve_kwargs or {}
try:
if "mark_as_read" not in retrieve_kwargs:
retrieve_kwargs["mark_as_read"] = False
cc_thread = Thread(id=thread_id).retrieve(**retrieve_kwargs)
course_key = CourseKey.from_string(cc_thread["course_id"])
course = _get_course_or_404(course_key, request.user)
context = get_context(course, request, cc_thread)
if (
not context["is_requester_privileged"] and
cc_thread["group_id"] and
is_commentable_cohorted(course.id, cc_thread["commentable_id"])
):
requester_cohort = get_cohort_id(request.user, course.id)
if requester_cohort is not None and cc_thread["group_id"] != requester_cohort:
raise Http404
return cc_thread, context
except CommentClientRequestError:
# params are validated at a higher level, so the only possible request
# error is if the thread doesn't exist
raise Http404
def _get_comment_and_context(request, comment_id):
"""
Retrieve the given comment and build a serializer context for it, returning
both. This function also enforces access control for the comment (checking
both the user's access to the course and to the comment's thread's cohort if
applicable). Raises Http404 if the comment does not exist or the user cannot
access it.
"""
try:
cc_comment = Comment(id=comment_id).retrieve()
_, context = _get_thread_and_context(request, cc_comment["thread_id"])
return cc_comment, context
except CommentClientRequestError:
raise Http404
def _is_user_author_or_privileged(cc_content, context):
"""
Check if the user is the author of a content object or a privileged user.
Returns:
Boolean
"""
return (
context["is_requester_privileged"] or
context["cc_requester"]["id"] == cc_content["user_id"]
)
def get_thread_list_url(request, course_key, topic_id_list):
"""
Returns the URL for the thread_list_url field, given a list of topic_ids
"""
path = reverse("thread-list")
query_list = [("course_id", unicode(course_key))] + [("topic_id", topic_id) for topic_id in topic_id_list]
return request.build_absolute_uri(urlunparse(("", "", path, "", urlencode(query_list), "")))
def get_course_topics(request, course_key):
"""
Return the course topic listing for the given course and user.
Parameters:
course_key: The key of the course to get topics for
user: The requesting user, for access control
Returns:
A course topic listing dictionary; see discussion_api.views.CourseTopicViews
for more detail.
"""
def get_module_sort_key(module):
"""
Get the sort key for the module (falling back to the discussion_target
setting if absent)
"""
return module.sort_key or module.discussion_target
course = _get_course_or_404(course_key, request.user)
discussion_modules = get_accessible_discussion_modules(course, request.user)
modules_by_category = defaultdict(list)
for module in discussion_modules:
modules_by_category[module.discussion_category].append(module)
def get_sorted_modules(category):
"""Returns key sorted modules by category"""
return sorted(modules_by_category[category], key=get_module_sort_key)
courseware_topics = [
{
"id": None,
"name": category,
"thread_list_url": get_thread_list_url(
request,
course_key,
[item.discussion_id for item in get_sorted_modules(category)]
),
"children": [
{
"id": module.discussion_id,
"name": module.discussion_target,
"thread_list_url": get_thread_list_url(request, course_key, [module.discussion_id]),
"children": [],
}
for module in get_sorted_modules(category)
],
}
for category in sorted(modules_by_category.keys())
]
non_courseware_topics = [
{
"id": entry["id"],
"name": name,
"thread_list_url": get_thread_list_url(request, course_key, [entry["id"]]),
"children": [],
}
for name, entry in sorted(
course.discussion_topics.items(),
key=lambda item: item[1].get("sort_key", item[0])
)
]
return {
"courseware_topics": courseware_topics,
"non_courseware_topics": non_courseware_topics,
}
def get_thread_list(request, course_key, page, page_size, topic_id_list=None):
"""
Return the list of all discussion threads pertaining to the given course
Parameters:
request: The django request objects used for build_absolute_uri
course_key: The key of the course to get discussion threads for
page: The page number (1-indexed) to retrieve
page_size: The number of threads to retrieve per page
topic_id_list: The list of topic_ids to get the discussion threads for
Returns:
A paginated result containing a list of threads; see
discussion_api.views.ThreadViewSet for more detail.
"""
course = _get_course_or_404(course_key, request.user)
context = get_context(course, request)
topic_ids_csv = ",".join(topic_id_list) if topic_id_list else None
threads, result_page, num_pages, _ = Thread.search({
"course_id": unicode(course.id),
"group_id": (
None if context["is_requester_privileged"] else
get_cohort_id(request.user, course.id)
),
"sort_key": "date",
"sort_order": "desc",
"page": page,
"per_page": page_size,
"commentable_ids": topic_ids_csv,
})
# The comments service returns the last page of results if the requested
# page is beyond the last page, but we want be consistent with DRF's general
# behavior and return a 404 in that case
if result_page != page:
raise Http404
results = [ThreadSerializer(thread, context=context).data for thread in threads]
return get_paginated_data(request, results, page, num_pages)
def get_comment_list(request, thread_id, endorsed, page, page_size):
"""
Return the list of comments in the given thread.
Parameters:
request: The django request object used for build_absolute_uri and
determining the requesting user.
thread_id: The id of the thread to get comments for.
endorsed: Boolean indicating whether to get endorsed or non-endorsed
comments (or None for all comments). Must be None for a discussion
thread and non-None for a question thread.
page: The page number (1-indexed) to retrieve
page_size: The number of comments to retrieve per page
Returns:
A paginated result containing a list of comments; see
discussion_api.views.CommentViewSet for more detail.
"""
response_skip = page_size * (page - 1)
cc_thread, context = _get_thread_and_context(
request,
thread_id,
retrieve_kwargs={
"recursive": True,
"user_id": request.user.id,
"mark_as_read": True,
"response_skip": response_skip,
"response_limit": page_size,
}
)
# Responses to discussion threads cannot be separated by endorsed, but
# responses to question threads must be separated by endorsed due to the
# existing comments service interface
if cc_thread["thread_type"] == "question":
if endorsed is None:
raise ValidationError({"endorsed": ["This field is required for question threads."]})
elif endorsed:
# CS does not apply resp_skip and resp_limit to endorsed responses
# of a question post
responses = cc_thread["endorsed_responses"][response_skip:(response_skip + page_size)]
resp_total = len(cc_thread["endorsed_responses"])
else:
responses = cc_thread["non_endorsed_responses"]
resp_total = cc_thread["non_endorsed_resp_total"]
else:
if endorsed is not None:
raise ValidationError(
{"endorsed": ["This field may not be specified for discussion threads."]}
)
responses = cc_thread["children"]
resp_total = cc_thread["resp_total"]
# The comments service returns the last page of results if the requested
# page is beyond the last page, but we want be consistent with DRF's general
# behavior and return a 404 in that case
if not responses and page != 1:
raise Http404
num_pages = (resp_total + page_size - 1) / page_size if resp_total else 1
results = [CommentSerializer(response, context=context).data for response in responses]
return get_paginated_data(request, results, page, num_pages)
def _do_extra_thread_actions(api_thread, cc_thread, request_fields, actions_form, context):
"""
Perform any necessary additional actions related to thread creation or
update that require a separate comments service request.
"""
for field, form_value in actions_form.cleaned_data.items():
if field in request_fields and form_value != api_thread[field]:
api_thread[field] = form_value
if field == "following":
if form_value:
context["cc_requester"].follow(cc_thread)
else:
context["cc_requester"].unfollow(cc_thread)
else:
assert field == "voted"
if form_value:
context["cc_requester"].vote(cc_thread, "up")
else:
context["cc_requester"].unvote(cc_thread)
def create_thread(request, thread_data):
"""
Create a thread.
Parameters:
request: The django request object used for build_absolute_uri and
determining the requesting user.
thread_data: The data for the created thread.
Returns:
The created thread; see discussion_api.views.ThreadViewSet for more
detail.
"""
course_id = thread_data.get("course_id")
if not course_id:
raise ValidationError({"course_id": ["This field is required."]})
try:
course_key = CourseKey.from_string(course_id)
course = _get_course_or_404(course_key, request.user)
except (Http404, InvalidKeyError):
raise ValidationError({"course_id": ["Invalid value."]})
context = get_context(course, request)
serializer = ThreadSerializer(data=thread_data, context=context)
actions_form = ThreadActionsForm(thread_data)
if not (serializer.is_valid() and actions_form.is_valid()):
raise ValidationError(dict(serializer.errors.items() + actions_form.errors.items()))
serializer.save()
cc_thread = serializer.object
api_thread = serializer.data
_do_extra_thread_actions(api_thread, cc_thread, thread_data.keys(), actions_form, context)
track_forum_event(
request,
THREAD_CREATED_EVENT_NAME,
course,
cc_thread,
get_thread_created_event_data(cc_thread, followed=actions_form.cleaned_data["following"])
)
return api_thread
def create_comment(request, comment_data):
"""
Create a comment.
Parameters:
request: The django request object used for build_absolute_uri and
determining the requesting user.
comment_data: The data for the created comment.
Returns:
The created comment; see discussion_api.views.CommentViewSet for more
detail.
"""
thread_id = comment_data.get("thread_id")
if not thread_id:
raise ValidationError({"thread_id": ["This field is required."]})
try:
cc_thread, context = _get_thread_and_context(request, thread_id)
except Http404:
raise ValidationError({"thread_id": ["Invalid value."]})
serializer = CommentSerializer(data=comment_data, context=context)
if not serializer.is_valid():
raise ValidationError(serializer.errors)
serializer.save()
cc_comment = serializer.object
track_forum_event(
request,
get_comment_created_event_name(cc_comment),
context["course"],
cc_comment,
get_comment_created_event_data(cc_comment, cc_thread["commentable_id"], followed=False)
)
return serializer.data
_THREAD_EDITABLE_BY_ANY = {"following", "voted"}
_THREAD_EDITABLE_BY_AUTHOR = {"topic_id", "type", "title", "raw_body"} | _THREAD_EDITABLE_BY_ANY
def _get_thread_editable_fields(cc_thread, context):
"""
Get the list of editable fields for the given thread in the given context
"""
if _is_user_author_or_privileged(cc_thread, context):
return _THREAD_EDITABLE_BY_AUTHOR
else:
return _THREAD_EDITABLE_BY_ANY
def _check_editable_fields(editable_fields, update_data):
"""
Raise ValidationError if the given update data contains a field that is not
in editable_fields.
"""
non_editable_errors = {
field: ["This field is not editable."]
for field in update_data.keys()
if field not in editable_fields
}
if non_editable_errors:
raise ValidationError(non_editable_errors)
def update_thread(request, thread_id, update_data):
"""
Update a thread.
Parameters:
request: The django request object used for build_absolute_uri and
determining the requesting user.
thread_id: The id for the thread to update.
update_data: The data to update in the thread.
Returns:
The updated thread; see discussion_api.views.ThreadViewSet for more
detail.
"""
cc_thread, context = _get_thread_and_context(request, thread_id)
editable_fields = _get_thread_editable_fields(cc_thread, context)
_check_editable_fields(editable_fields, update_data)
serializer = ThreadSerializer(cc_thread, data=update_data, partial=True, context=context)
actions_form = ThreadActionsForm(update_data)
if not (serializer.is_valid() and actions_form.is_valid()):
raise ValidationError(dict(serializer.errors.items() + actions_form.errors.items()))
# Only save thread object if some of the edited fields are in the thread data, not extra actions
if set(update_data) - set(actions_form.fields):
serializer.save()
api_thread = serializer.data
_do_extra_thread_actions(api_thread, cc_thread, update_data.keys(), actions_form, context)
return api_thread
_COMMENT_EDITABLE_BY_AUTHOR = {"raw_body"}
_COMMENT_EDITABLE_BY_THREAD_AUTHOR = {"endorsed"}
def _get_comment_editable_fields(cc_comment, context):
"""
Get the list of editable fields for the given comment in the given context
"""
ret = set()
if _is_user_author_or_privileged(cc_comment, context):
ret |= _COMMENT_EDITABLE_BY_AUTHOR
if _is_user_author_or_privileged(context["thread"], context):
ret |= _COMMENT_EDITABLE_BY_THREAD_AUTHOR
return ret
def update_comment(request, comment_id, update_data):
"""
Update a comment.
Parameters:
request: The django request object used for build_absolute_uri and
determining the requesting user.
comment_id: The id for the comment to update.
update_data: The data to update in the comment.
Returns:
The updated comment; see discussion_api.views.CommentViewSet for more
detail.
Raises:
Http404: if the comment does not exist or is not accessible to the
requesting user
PermissionDenied: if the comment is accessible to but not editable by
the requesting user
ValidationError: if there is an error applying the update (e.g. raw_body
is empty or thread_id is included)
"""
cc_comment, context = _get_comment_and_context(request, comment_id)
editable_fields = _get_comment_editable_fields(cc_comment, context)
_check_editable_fields(editable_fields, update_data)
serializer = CommentSerializer(cc_comment, data=update_data, partial=True, context=context)
if not serializer.is_valid():
raise ValidationError(serializer.errors)
# Only save comment object if the comment is actually modified
if update_data:
serializer.save()
return serializer.data
def delete_thread(request, thread_id):
"""
Delete a thread.
Parameters:
request: The django request object used for build_absolute_uri and
determining the requesting user.
thread_id: The id for the thread to delete
Raises:
PermissionDenied: if user does not have permission to delete thread
"""
cc_thread, context = _get_thread_and_context(request, thread_id)
if _is_user_author_or_privileged(cc_thread, context):
cc_thread.delete()
else:
raise PermissionDenied
def delete_comment(request, comment_id):
"""
Delete a comment.
Parameters:
request: The django request object used for build_absolute_uri and
determining the requesting user.
comment_id: The id of the comment to delete
Raises:
PermissionDenied: if user does not have permission to delete thread
"""
cc_comment, context = _get_comment_and_context(request, comment_id)
if _is_user_author_or_privileged(cc_comment, context):
cc_comment.delete()
else:
raise PermissionDenied