Files
edx-platform/cms/djangoapps/contentstore/views/preview.py
2013-07-31 15:42:11 -04:00

178 lines
6.0 KiB
Python

import logging
import sys
from functools import partial
from django.http import HttpResponse, Http404, HttpResponseBadRequest, HttpResponseForbidden
from django.core.urlresolvers import reverse
from django.contrib.auth.decorators import login_required
from mitxmako.shortcuts import render_to_response
from xmodule_modifiers import replace_static_urls, wrap_xmodule, save_module # pylint: disable=F0401
from xmodule.error_module import ErrorDescriptor
from xmodule.errortracker import exc_info_to_str
from xmodule.exceptions import NotFoundError, ProcessingError
from xmodule.modulestore import Location
from xmodule.modulestore.django import modulestore
from xmodule.modulestore.mongo import MongoUsage
from xmodule.x_module import ModuleSystem
from xblock.runtime import DbModel
from util.sandboxing import can_execute_unsafe_code
import static_replace
from .session_kv_store import SessionKeyValueStore
from .requests import render_from_lms
from .access import has_access
from ..utils import get_course_for_item
__all__ = ['preview_dispatch', 'preview_component']
log = logging.getLogger(__name__)
@login_required
def preview_dispatch(request, preview_id, location, dispatch=None):
"""
Dispatch an AJAX action to a preview XModule
Expects a POST request, and passes the arguments to the module
preview_id (str): An identifier specifying which preview this module is used for
location: The Location of the module to dispatch to
dispatch: The action to execute
"""
descriptor = modulestore().get_item(location)
instance = load_preview_module(request, preview_id, descriptor)
# Let the module handle the AJAX
try:
ajax_return = instance.handle_ajax(dispatch, request.POST)
# Save any module data that has changed to the underlying KeyValueStore
instance.save()
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
except ProcessingError:
log.warning("Module raised an error while processing AJAX request",
exc_info=True)
return HttpResponseBadRequest()
except:
log.exception("error processing ajax call")
raise
return HttpResponse(ajax_return)
@login_required
def preview_component(request, location):
"Return the HTML preview of a component"
# TODO (vshnayder): change name from id to location in coffee+html as well.
if not has_access(request.user, location):
return HttpResponseForbidden()
component = modulestore().get_item(location)
return render_to_response('component.html', {
'preview': get_module_previews(request, component)[0],
'editor': wrap_xmodule(component.get_html, component, 'xmodule_edit.html')(),
})
def preview_module_system(request, preview_id, descriptor):
"""
Returns a ModuleSystem for the specified descriptor that is specialized for
rendering module previews.
request: The active django request
preview_id (str): An identifier specifying which preview this module is used for
descriptor: An XModuleDescriptor
"""
def preview_model_data(descriptor):
"Helper method to create a DbModel from a descriptor"
return DbModel(
SessionKeyValueStore(request, descriptor._model_data),
descriptor.module_class,
preview_id,
MongoUsage(preview_id, descriptor.location.url()),
)
course_id = get_course_for_item(descriptor.location).location.course_id
return ModuleSystem(
ajax_url=reverse('preview_dispatch', args=[preview_id, descriptor.location.url(), '']).rstrip('/'),
# TODO (cpennington): Do we want to track how instructors are using the preview problems?
track_function=lambda event_type, event: None,
filestore=descriptor.system.resources_fs,
get_module=partial(load_preview_module, request, preview_id),
render_template=render_from_lms,
debug=True,
replace_urls=partial(static_replace.replace_static_urls, data_directory=None, course_namespace=descriptor.location),
user=request.user,
xblock_model_data=preview_model_data,
can_execute_unsafe_code=(lambda: can_execute_unsafe_code(course_id)),
)
def load_preview_module(request, preview_id, descriptor):
"""
Return a preview XModule instantiated from the supplied descriptor.
request: The active django request
preview_id (str): An identifier specifying which preview this module is used for
descriptor: An XModuleDescriptor
"""
system = preview_module_system(request, preview_id, descriptor)
try:
module = descriptor.xmodule(system)
except:
log.debug("Unable to load preview module", exc_info=True)
module = ErrorDescriptor.from_descriptor(
descriptor,
error_msg=exc_info_to_str(sys.exc_info())
).xmodule(system)
# cdodge: Special case
if module.location.category == 'static_tab':
module.get_html = wrap_xmodule(
module.get_html,
module,
"xmodule_tab_display.html",
)
else:
module.get_html = wrap_xmodule(
module.get_html,
module,
"xmodule_display.html",
)
module.get_html = replace_static_urls(
module.get_html,
getattr(module, 'data_dir', module.location.course),
course_namespace=Location([module.location.tag, module.location.org, module.location.course, None, None])
)
module.get_html = save_module(
module.get_html,
module
)
return module
def get_module_previews(request, descriptor):
"""
Returns a list of preview XModule html contents. One preview is returned for each
pair of states returned by get_sample_state() for the supplied descriptor.
descriptor: An XModuleDescriptor
"""
preview_html = []
for idx, (_instance_state, _shared_state) in enumerate(descriptor.get_sample_state()):
module = load_preview_module(request, str(idx), descriptor)
preview_html.append(module.get_html())
return preview_html