Files
edx-platform/cms/djangoapps/contentstore/views/item.py
Don Mitchell badf86f71b Have save_item parse json formatted field values by type
including allowing javascript to serialize date/time natively.
2013-07-18 16:48:29 -04:00

188 lines
7.7 KiB
Python

import json
from uuid import uuid4
from django.core.exceptions import PermissionDenied
from django.http import HttpResponse
from django.contrib.auth.decorators import login_required
from xmodule.modulestore import Location
from xmodule.modulestore.django import modulestore
from xmodule.modulestore.inheritance import own_metadata
from util.json_request import expect_json
from ..utils import get_modulestore
from .access import has_access
from .requests import _xmodule_recurse
from xmodule.x_module import XModuleDescriptor
__all__ = ['save_item', 'create_item', 'delete_item']
# cdodge: these are categories which should not be parented, they are detached from the hierarchy
DETACHED_CATEGORIES = ['about', 'static_tab', 'course_info']
@login_required
@expect_json
def save_item(request):
"""
Will carry a json payload with these possible fields
:id (required): the id
:data (optional): the new value for the data
:metadata (optional): 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 (optional): which metadata fields to set to None
"""
# The nullout is a bit of a temporary copout until we can make module_edit.coffee and the metadata editors a
# little smarter and able to pass something more akin to {unset: [field, field]}
item_location = request.POST['id']
# check permissions for this user within this course
if not has_access(request.user, item_location):
raise PermissionDenied()
store = get_modulestore(Location(item_location))
if request.POST.get('data') is not None:
data = request.POST['data']
store.update_item(item_location, data)
# cdodge: note calling request.POST.get('children') will return None if children is an empty array
# so it lead to a bug whereby the last component to be deleted in the UI was not actually
# deleting the children object from the children collection
if 'children' in request.POST and request.POST['children'] is not None:
children = request.POST['children']
store.update_children(item_location, children)
# cdodge: also commit any metadata which might have been passed along
if request.POST.get('nullout') is not None or request.POST.get('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 fetch the original and
# 'apply' the submitted metadata, so we don't end up deleting system metadata
existing_item = modulestore().get_item(item_location)
for metadata_key in request.POST.get('nullout', []):
# [dhm] see comment on _get_xblock_field
_get_xblock_field(existing_item, metadata_key).write_to(existing_item, 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
for metadata_key, value in request.POST.get('metadata', {}).items():
# [dhm] see comment on _get_xblock_field
field = _get_xblock_field(existing_item, metadata_key)
if value is None:
field.delete_from(existing_item)
else:
value = field.from_json(value)
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))
return HttpResponse()
# [DHM] A hack until we implement a permanent soln. Proposed perm solution is to make namespace fields also top level
# fields in xblocks rather than requiring dereference through namespace but we'll need to consider whether there are
# plausible use cases for distinct fields w/ same name in different namespaces on the same blocks.
# The idea is that consumers of the xblock, and particularly the web client, shouldn't know about our internal
# representation (namespaces as means of decorating all modules).
# Given top-level access, the calls can simply be setattr(existing_item, field, value) ...
# Really, this method should be elsewhere (e.g., xblock). We also need methods for has_value (v is_default)...
def _get_xblock_field(xblock, field_name):
"""
A temporary function to get the xblock field either from the xblock or one of its namespaces by name.
:param xblock:
:param field_name:
"""
def find_field(fields):
for field in fields:
if field.name == field_name:
return field
found = find_field(xblock.fields)
if found:
return found
for namespace in xblock.namespaces:
found = find_field(getattr(xblock, namespace).fields)
if found:
return found
@login_required
@expect_json
def create_item(request):
parent_location = Location(request.POST['parent_location'])
category = request.POST['category']
display_name = request.POST.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.POST.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()])
return HttpResponse(json.dumps({'id': dest_location.url()}))
@login_required
@expect_json
def delete_item(request):
item_location = request.POST['id']
item_location = Location(item_location)
# check permissions for this user within this course
if not has_access(request.user, item_location):
raise PermissionDenied()
# optional parameter to delete all children (default False)
delete_children = request.POST.get('delete_children', False)
delete_all_versions = request.POST.get('delete_all_versions', False)
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 HttpResponse()