Files
edx-platform/cms/djangoapps/contentstore/views/item.py

383 lines
16 KiB
Python

"""Views for items (modules)."""
import logging
from uuid import uuid4
from functools import partial
from static_replace import replace_static_urls
from xmodule_modifiers import wrap_xblock
from django.core.exceptions import PermissionDenied
from django.contrib.auth.decorators import login_required
from xmodule.modulestore.django import modulestore, loc_mapper
from xmodule.modulestore.inheritance import own_metadata
from xmodule.modulestore.exceptions import ItemNotFoundError, InvalidLocationError
from util.json_request import expect_json, JsonResponse
from util.string_utils import str_to_bool
from ..transcripts_utils import manage_video_subtitles_save
from ..utils import get_modulestore
from .access import has_access
from .helpers import _xmodule_recurse
from xmodule.x_module import XModuleDescriptor
from django.views.decorators.http import require_http_methods
from xmodule.modulestore.locator import BlockUsageLocator
from student.models import CourseEnrollment
from django.http import HttpResponseBadRequest
from xblock.fields import Scope
from preview import handler_prefix, get_preview_html
from mitxmako.shortcuts import render_to_response, render_to_string
from models.settings.course_grading import CourseGradingModel
__all__ = ['orphan_handler', 'xblock_handler']
log = logging.getLogger(__name__)
# cdodge: these are categories which should not be parented, they are detached from the hierarchy
DETACHED_CATEGORIES = ['about', 'static_tab', 'course_info']
CREATE_IF_NOT_FOUND = ['course_info']
# pylint: disable=unused-argument
@require_http_methods(("DELETE", "GET", "PUT", "POST"))
@login_required
@expect_json
def xblock_handler(request, tag=None, course_id=None, branch=None, version_guid=None, block=None):
"""
The restful handler for xblock requests.
DELETE
json: delete this xblock instance from the course. Supports query parameters "recurse" to delete
all children and "all_versions" to delete from all (mongo) versions.
GET
json: returns representation of the xblock (locator id, data, and metadata).
if ?fields=graderType, it returns the graderType for the unit instead of the above.
html: returns HTML for rendering the xblock (which includes both the "preview" view and the "editor" view)
PUT or POST
json: if xblock locator is specified, update the xblock instance. The json payload can contain
these fields, all optional:
:data: the new value for the data.
:children: the locator ids of children for this xblock.
:metadata: new values for the metadata fields. Any whose values are None will be deleted not set
to None! Absent ones will be left alone.
:nullout: which metadata fields to set to None
:graderType: change how this unit is graded
:publish: can be one of three values, 'make_public, 'make_private', or 'create_draft'
The JSON representation on the updated xblock (minus children) is returned.
if xblock locator is not specified, create a new xblock instance. The json playload can contain
these fields:
:parent_locator: parent for new xblock, required
:category: type of xblock, required
:display_name: name for new xblock, optional
:boilerplate: template name for populating fields, optional
The locator (and old-style id) for the created xblock (minus children) is returned.
"""
if course_id is not None:
locator = BlockUsageLocator(course_id=course_id, branch=branch, version_guid=version_guid, usage_id=block)
if not has_access(request.user, locator):
raise PermissionDenied()
old_location = loc_mapper().translate_locator_to_location(locator)
if request.method == 'GET':
if 'application/json' in request.META.get('HTTP_ACCEPT', 'application/json'):
fields = request.REQUEST.get('fields', '').split(',')
if 'graderType' in fields:
# right now can't combine output of this w/ output of _get_module_info, but worthy goal
return JsonResponse(CourseGradingModel.get_section_grader_type(locator))
# TODO: pass fields to _get_module_info and only return those
rsp = _get_module_info(locator)
return JsonResponse(rsp)
else:
component = modulestore().get_item(old_location)
# Wrap the generated fragment in the xmodule_editor div so that the javascript
# can bind to it correctly
component.runtime.wrappers.append(partial(wrap_xblock, handler_prefix))
try:
content = component.render('studio_view').content
# catch exceptions indiscriminately, since after this point they escape the
# dungeon and surface as uneditable, unsaveable, and undeletable
# component-goblins.
except Exception as exc: # pylint: disable=W0703
content = render_to_string('html_error.html', {'message': str(exc)})
return render_to_response('component.html', {
'preview': get_preview_html(request, component),
'editor': content
})
elif request.method == 'DELETE':
delete_children = str_to_bool(request.REQUEST.get('recurse', 'False'))
delete_all_versions = str_to_bool(request.REQUEST.get('all_versions', 'False'))
return _delete_item_at_location(old_location, delete_children, delete_all_versions)
else: # Since we have a course_id, we are updating an existing xblock.
return _save_item(
request,
locator,
old_location,
data=request.json.get('data'),
children=request.json.get('children'),
metadata=request.json.get('metadata'),
nullout=request.json.get('nullout'),
grader_type=request.json.get('graderType'),
publish=request.json.get('publish'),
)
elif request.method in ('PUT', 'POST'):
return _create_item(request)
else:
return HttpResponseBadRequest(
"Only instance creation is supported without a course_id.",
content_type="text/plain"
)
def _save_item(request, usage_loc, item_location, data=None, children=None, metadata=None, nullout=None,
grader_type=None, publish=None):
"""
Saves xblock w/ its fields. Has special processing for grader_type, publish, and nullout and Nones in metadata.
nullout means to truly set the field to None whereas nones in metadata mean to unset them (so they revert
to default).
The item_location is still the old-style location whereas usage_loc is a BlockUsageLocator
"""
store = get_modulestore(item_location)
try:
existing_item = store.get_item(item_location)
except ItemNotFoundError:
if item_location.category in CREATE_IF_NOT_FOUND:
# New module at this location, for pages that are not pre-created.
# Used for course info handouts.
store.create_and_save_xmodule(item_location)
existing_item = store.get_item(item_location)
else:
raise
except InvalidLocationError:
log.error("Can't find item by location.")
return JsonResponse({"error": "Can't find item by location: " + str(item_location)}, 404)
if publish:
if publish == 'make_private':
_xmodule_recurse(existing_item, lambda i: modulestore().unpublish(i.location))
elif publish == 'create_draft':
# This clones the existing item location to a draft location (the draft is
# implicit, because modulestore is a Draft modulestore)
modulestore().convert_to_draft(item_location)
if data:
store.update_item(item_location, data)
else:
data = existing_item.get_explicitly_set_fields_by_scope(Scope.content)
if children is not None:
children_ids = [
loc_mapper().translate_locator_to_location(BlockUsageLocator(child_locator)).url()
for child_locator
in children
]
store.update_children(item_location, children_ids)
# cdodge: also commit any metadata which might have been passed along
if nullout is not None or metadata is not None:
# the postback is not the complete metadata, as there's system metadata which is
# not presented to the end-user for editing. So let's use the original (existing_item) and
# 'apply' the submitted metadata, so we don't end up deleting system metadata.
if nullout is not None:
for metadata_key in nullout:
setattr(existing_item, metadata_key, None)
# update existing metadata with submitted metadata (which can be partial)
# IMPORTANT NOTE: if the client passed 'null' (None) for a piece of metadata that means 'remove it'. If
# the intent is to make it None, use the nullout field
if metadata is not None:
for metadata_key, value in metadata.items():
field = existing_item.fields[metadata_key]
if value is None:
field.delete_from(existing_item)
else:
try:
value = field.from_json(value)
except ValueError:
return JsonResponse({"error": "Invalid data"}, 400)
field.write_to(existing_item, value)
# Save the data that we've just changed to the underlying
# MongoKeyValueStore before we update the mongo datastore.
existing_item.save()
# commit to datastore
store.update_metadata(item_location, own_metadata(existing_item))
if existing_item.category == 'video':
manage_video_subtitles_save(existing_item, existing_item)
result = {
'id': unicode(usage_loc),
'data': data,
'metadata': own_metadata(existing_item)
}
if grader_type is not None:
result.update(CourseGradingModel.update_section_grader_type(existing_item, grader_type))
# Make public after updating the xblock, in case the caller asked
# for both an update and a publish.
if publish and publish == 'make_public':
_xmodule_recurse(
existing_item,
lambda i: modulestore().publish(i.location, request.user.id)
)
# Note that children aren't being returned until we have a use case.
return JsonResponse(result)
@login_required
@expect_json
def _create_item(request):
"""View for create items."""
parent_locator = BlockUsageLocator(request.json['parent_locator'])
parent_location = loc_mapper().translate_locator_to_location(parent_locator)
category = request.json['category']
display_name = request.json.get('display_name')
if not has_access(request.user, parent_location):
raise PermissionDenied()
parent = get_modulestore(category).get_item(parent_location)
dest_location = parent_location.replace(category=category, name=uuid4().hex)
# get the metadata, display_name, and definition from the request
metadata = {}
data = None
template_id = request.json.get('boilerplate')
if template_id is not None:
clz = XModuleDescriptor.load_class(category)
if clz is not None:
template = clz.get_template(template_id)
if template is not None:
metadata = template.get('metadata', {})
data = template.get('data')
if display_name is not None:
metadata['display_name'] = display_name
get_modulestore(category).create_and_save_xmodule(
dest_location,
definition_data=data,
metadata=metadata,
system=parent.system,
)
if category not in DETACHED_CATEGORIES:
get_modulestore(parent.location).update_children(parent_location, parent.children + [dest_location.url()])
course_location = loc_mapper().translate_locator_to_location(parent_locator, get_course=True)
locator = loc_mapper().translate_location(course_location.course_id, dest_location, False, True)
return JsonResponse({"locator": unicode(locator)})
def _delete_item_at_location(item_location, delete_children=False, delete_all_versions=False):
"""
Deletes the item at with the given Location.
It is assumed that course permissions have already been checked.
"""
store = get_modulestore(item_location)
item = store.get_item(item_location)
if delete_children:
_xmodule_recurse(item, lambda i: store.delete_item(i.location, delete_all_versions))
else:
store.delete_item(item.location, delete_all_versions)
# cdodge: we need to remove our parent's pointer to us so that it is no longer dangling
if delete_all_versions:
parent_locs = modulestore('direct').get_parent_locations(item_location, None)
for parent_loc in parent_locs:
parent = modulestore('direct').get_item(parent_loc)
item_url = item_location.url()
if item_url in parent.children:
children = parent.children
children.remove(item_url)
parent.children = children
modulestore('direct').update_children(parent.location, parent.children)
return JsonResponse()
# pylint: disable=W0613
@login_required
@require_http_methods(("GET", "DELETE"))
def orphan_handler(request, tag=None, course_id=None, branch=None, version_guid=None, block=None):
"""
View for handling orphan related requests. GET gets all of the current orphans.
DELETE removes all orphans (requires is_staff access)
An orphan is a block whose category is not in the DETACHED_CATEGORY list, is not the root, and is not reachable
from the root via children
:param request:
:param course_id: Locator syntax course_id
"""
location = BlockUsageLocator(course_id=course_id, branch=branch, version_guid=version_guid, usage_id=block)
# DHM: when split becomes back-end, move or conditionalize this conversion
old_location = loc_mapper().translate_locator_to_location(location)
if request.method == 'GET':
if has_access(request.user, old_location):
return JsonResponse(modulestore().get_orphans(old_location, DETACHED_CATEGORIES, 'draft'))
else:
raise PermissionDenied()
if request.method == 'DELETE':
if request.user.is_staff:
items = modulestore().get_orphans(old_location, DETACHED_CATEGORIES, 'draft')
for item in items:
modulestore('draft').delete_item(item, True)
return JsonResponse({'deleted': items})
else:
raise PermissionDenied()
def _get_module_info(usage_loc, rewrite_static_links=True):
"""
metadata, data, id representation of a leaf module fetcher.
:param usage_loc: A BlockUsageLocator
"""
old_location = loc_mapper().translate_locator_to_location(usage_loc)
store = get_modulestore(old_location)
try:
module = store.get_item(old_location)
except ItemNotFoundError:
if old_location.category in CREATE_IF_NOT_FOUND:
# Create a new one for certain categories only. Used for course info handouts.
store.create_and_save_xmodule(old_location)
module = store.get_item(old_location)
else:
raise
data = module.data
if rewrite_static_links:
# we pass a partially bogus course_id as we don't have the RUN information passed yet
# through the CMS. Also the contentstore is also not RUN-aware at this point in time.
data = replace_static_urls(
module.data,
None,
course_id=module.location.org + '/' + module.location.course + '/BOGUS_RUN_REPLACE_WHEN_AVAILABLE'
)
# Note that children aren't being returned until we have a use case.
return {
'id': unicode(usage_loc),
'data': data,
'metadata': own_metadata(module)
}