def component_handler(request, usage_key_string, handler, suffix=''):
"""
Dispatch an AJAX action to an xblock
Args:
usage_id: The usage-id of the block to dispatch to
handler (str): The handler to execute
suffix (str): The remainder of the url to be passed to the handler
Returns:
:class:`django.http.HttpResponse`: The response from the handler, converted to a
django response
"""
usage_key = UsageKey.from_string(usage_key_string)
descriptor = modulestore().get_item(usage_key)
descriptor.xmodule_runtime = StudioEditModuleRuntime(request.user)
# Let the module handle the AJAX
req = django_to_webob_request(request)
try:
resp = descriptor.handle(handler, req, suffix)
except NoSuchHandlerError:
log.info("XBlock %s attempted to access missing handler %r", descriptor, handler, exc_info=True)
raise Http404
# unintentional update to handle any side effects of handle call
# could potentially be updating actual course data or simply caching its values
modulestore().update_item(descriptor, request.user.id)
return webob_to_django_response(resp)
def component_handler(request, usage_id, handler, suffix=""):
"""
Dispatch an AJAX action to an xblock
Args:
usage_id: The usage-id of the block to dispatch to, passed through `quote_slashes`
handler (str): The handler to execute
suffix (str): The remainder of the url to be passed to the handler
Returns:
:class:`django.http.HttpResponse`: The response from the handler, converted to a
django response
"""
location = unquote_slashes(usage_id)
descriptor = modulestore().get_item(location)
# Let the module handle the AJAX
req = django_to_webob_request(request)
try:
resp = descriptor.handle(handler, req, suffix)
except NoSuchHandlerError:
log.info("XBlock %s attempted to access missing handler %r", descriptor, handler, exc_info=True)
raise Http404
modulestore().save_xmodule(descriptor)
return webob_to_django_response(resp)
def preview_handler(request, usage_key_string, handler, suffix=''):
"""
Dispatch an AJAX action to an xblock
usage_key_string: The usage_key_string-id of the block to dispatch to, passed through `quote_slashes`
handler: The handler to execute
suffix: The remainder of the url to be passed to the handler
"""
usage_key = UsageKey.from_string(usage_key_string)
descriptor = modulestore().get_item(usage_key)
instance = _load_preview_module(request, descriptor)
# Let the module handle the AJAX
req = django_to_webob_request(request)
try:
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
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 Exception:
log.exception("error processing ajax call")
raise
return webob_to_django_response(resp)
def component_handler(request, usage_key_string, handler, suffix=''):
"""
Dispatch an AJAX action to an xblock
Args:
usage_id: The usage-id of the block to dispatch to
handler (str): The handler to execute
suffix (str): The remainder of the url to be passed to the handler
Returns:
:class:`django.http.HttpResponse`: The response from the handler, converted to a
django response
"""
usage_key = UsageKey.from_string(usage_key_string)
descriptor = get_modulestore(usage_key).get_item(usage_key)
# Let the module handle the AJAX
req = django_to_webob_request(request)
try:
resp = descriptor.handle(handler, req, suffix)
except NoSuchHandlerError:
log.info("XBlock %s attempted to access missing handler %r", descriptor, handler, exc_info=True)
raise Http404
# unintentional update to handle any side effects of handle call; so, request user didn't author
# the change
get_modulestore(usage_key).update_item(descriptor, None)
return webob_to_django_response(resp)
def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix, user):
"""
Invoke an XBlock handler, either authenticated or not.
"""
location = unquote_slashes(usage_id)
# Check parameters and fail fast if there's a problem
if not Location.is_valid(location):
raise Http404("Invalid location")
# Check submitted files
files = request.FILES or {}
error_msg = _check_files_limits(files)
if error_msg:
return HttpResponse(json.dumps({"success": error_msg}))
try:
descriptor = modulestore().get_instance(course_id, location)
except ItemNotFoundError:
log.warn(
"Invalid location for course id {course_id}: {location}".format(course_id=course_id, location=location)
)
raise Http404
field_data_cache = FieldDataCache.cache_for_descriptor_descendents(course_id, user, descriptor)
instance = get_module(user, request, location, field_data_cache, course_id, grade_bucket_type="ajax")
if instance is None:
# Either permissions just changed, or someone is trying to be clever
# and load something they shouldn't have access to.
log.debug("No module %s for user %s -- access denied?", location, user)
raise Http404
req = django_to_webob_request(request)
try:
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
# If we can't find the module, respond with a 404
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
# For XModule-specific errors, we log the error and respond with an error message
except ProcessingError as err:
log.warning("Module encountered an error while processing AJAX call", exc_info=True)
return JsonResponse(object={"success": err.args[0]}, status=200)
# If any other error occurred, re-raise it to trigger a 500 response
except Exception:
log.exception("error executing xblock handler")
raise
return webob_to_django_response(resp)
def test_post_already_read(self):
# Check that POST already having been read from doesn't
# prevent access to the POST of the webob object
dj_req = self.req_factory.post('dummy_url', data={'foo': 'bar'})
# Read from POST before constructing the webob request
self.assertEqual(dj_req.POST.getlist('foo'), ['bar']) # pylint: disable=no-member
webob_req = django_to_webob_request(dj_req)
self.assertEqual(webob_req.POST.getall('foo'), ['bar'])
def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix):
"""
Invoke an XBlock handler, either authenticated or not.
Arguments:
request (HttpRequest): the current request
course_id (str): A string of the form org/course/run
usage_id (str): A string of the form i4x://org/course/category/name@revision
handler (str): The name of the handler to invoke
suffix (str): The suffix to pass to the handler when invoked
"""
# Check submitted files
files = request.FILES or {}
error_msg = _check_files_limits(files)
if error_msg:
return JsonResponse(object={'success': error_msg}, status=413)
instance, tracking_context = get_module_by_usage_id(request, course_id, usage_id)
# Name the transaction so that we can view XBlock handlers separately in
# New Relic. The suffix is necessary for XModule handlers because the
# "handler" in those cases is always just "xmodule_handler".
nr_tx_name = "{}.{}".format(instance.__class__.__name__, handler)
nr_tx_name += "/{}".format(suffix) if suffix else ""
newrelic.agent.set_transaction_name(nr_tx_name, group="Python/XBlock/Handler")
tracking_context_name = 'module_callback_handler'
req = django_to_webob_request(request)
try:
with tracker.get_tracker().context(tracking_context_name, tracking_context):
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
# If we can't find the module, respond with a 404
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
# For XModule-specific errors, we log the error and respond with an error message
except ProcessingError as err:
log.warning("Module encountered an error while processing AJAX call",
exc_info=True)
return JsonResponse(object={'success': err.args[0]}, status=200)
# If any other error occurred, re-raise it to trigger a 500 response
except Exception:
log.exception("error executing xblock handler")
raise
return webob_to_django_response(resp)
def handler(request, usage_id, handler_slug):
"""Provide a handler for the request."""
student_id = get_student_id(request)
log.info("Start handler %s/%s for student %s", usage_id, handler_slug, student_id)
runtime = WorkbenchRuntime(student_id)
block = runtime.get_block(usage_id)
request = django_to_webob_request(request)
request.path_info_pop()
request.path_info_pop()
result = block.runtime.handle(block, handler_slug, request)
log.info("End handler %s/%s", usage_id, handler_slug)
return webob_to_django_response(result)
def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix):
"""
Invoke an XBlock handler, either authenticated or not.
Arguments:
request (HttpRequest): the current request
course_id (str): A string of the form org/course/run
usage_id (str): A string of the form i4x://org/course/category/name@revision
handler (str): The name of the handler to invoke
suffix (str): The suffix to pass to the handler when invoked
"""
# Check submitted files
files = request.FILES or {}
error_msg = _check_files_limits(files)
if error_msg:
return JsonResponse(object={'success': error_msg}, status=413)
instance, tracking_context = _get_module_by_usage_id(request, course_id, usage_id)
tracking_context_name = 'module_callback_handler'
req = django_to_webob_request(request)
try:
with tracker.get_tracker().context(tracking_context_name, tracking_context):
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
# If we can't find the module, respond with a 404
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
# For XModule-specific errors, we log the error and respond with an error message
except ProcessingError as err:
log.warning("Module encountered an error while processing AJAX call",
exc_info=True)
return JsonResponse(object={'success': err.args[0]}, status=200)
# If any other error occurred, re-raise it to trigger a 500 response
except Exception:
log.exception("error executing xblock handler")
raise
return webob_to_django_response(resp)
def preview_handler(request, usage_key_string, handler, suffix=""):
"""
Dispatch an AJAX action to an xblock
usage_key_string: The usage_key_string-id of the block to dispatch to, passed through `quote_slashes`
handler: The handler to execute
suffix: The remainder of the url to be passed to the handler
"""
usage_key = UsageKey.from_string(usage_key_string)
if isinstance(usage_key, AsideUsageKeyV1):
descriptor = modulestore().get_item(usage_key.usage_key)
for aside in descriptor.runtime.get_asides(descriptor):
if aside.scope_ids.block_type == usage_key.aside_type:
asides = [aside]
instance = aside
break
else:
descriptor = modulestore().get_item(usage_key)
instance = _load_preview_module(request, descriptor)
asides = []
# Let the module handle the AJAX
req = django_to_webob_request(request)
try:
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
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 Exception:
log.exception("error processing ajax call")
raise
modulestore().update_item(descriptor, request.user.id, asides=asides)
return webob_to_django_response(resp)
def handler(request, usage_id, handler_slug, suffix='', authenticated=True):
"""The view function for authenticated handler requests."""
if authenticated:
student_id = get_student_id(request)
log.info("Start handler %s/%s for student %s", usage_id, handler_slug, student_id)
else:
student_id = "none"
log.info("Start handler %s/%s", usage_id, handler_slug)
runtime = WorkbenchRuntime(student_id)
try:
block = runtime.get_block(usage_id)
except NoSuchUsage:
raise Http404
request = django_to_webob_request(request)
request.path_info_pop()
request.path_info_pop()
result = block.runtime.handle(block, handler_slug, request, suffix)
log.info("End handler %s/%s", usage_id, handler_slug)
return webob_to_django_response(result)
def preview_handler(request, usage_key_string, handler, suffix=''):
"""
Dispatch an AJAX action to an xblock
usage_key_string: The usage_key_string-id of the block to dispatch to, passed through `quote_slashes`
handler: The handler to execute
suffix: The remainder of the url to be passed to the handler
"""
usage_key = UsageKey.from_string(usage_key_string)
descriptor = modulestore().get_item(usage_key)
instance = _load_preview_module(request, descriptor)
# Let the module handle the AJAX
req = django_to_webob_request(request)
try:
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception(u"XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
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 Exception:
log.exception("error processing ajax call")
raise
return webob_to_django_response(resp)
def handle_xblock_callback(request, course_id, usage_id, handler, suffix=None):
"""
Generic view for extensions. This is where AJAX calls go.
Arguments:
- request -- the django request.
- location -- the module location. Used to look up the XModule instance
- course_id -- defines the course context for this request.
Raises PermissionDenied if the user is not logged in. Raises Http404 if
the location and course_id do not identify a valid module, the module is
not accessible by the user, or the module raises NotFoundError. If the
module raises any other error, it will escape this function.
"""
location = unquote_slashes(usage_id)
# Check parameters and fail fast if there's a problem
if not Location.is_valid(location):
raise Http404("Invalid location")
if not request.user.is_authenticated():
raise PermissionDenied
# Check submitted files
files = request.FILES or {}
error_msg = _check_files_limits(files)
if error_msg:
return HttpResponse(json.dumps({'success': error_msg}))
try:
descriptor = modulestore().get_instance(course_id, location)
except ItemNotFoundError:
log.warn(
"Invalid location for course id {course_id}: {location}".format(
course_id=course_id,
location=location
)
)
raise Http404
field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
course_id,
request.user,
descriptor
)
instance = get_module(request.user, request, location, field_data_cache, course_id, grade_bucket_type='ajax')
if instance is None:
# Either permissions just changed, or someone is trying to be clever
# and load something they shouldn't have access to.
log.debug("No module %s for user %s -- access denied?", location, request.user)
raise Http404
req = django_to_webob_request(request)
try:
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
# If we can't find the module, respond with a 404
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
# For XModule-specific errors, we log the error and respond with an error message
except ProcessingError as err:
log.warning("Module encountered an error while processing AJAX call",
exc_info=True)
return JsonResponse(object={'success': err.args[0]}, status=200)
# If any other error occurred, re-raise it to trigger a 500 response
except Exception:
log.exception("error executing xblock handler")
raise
return webob_to_django_response(resp)
def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix,
user):
"""
Invoke an XBlock handler, either authenticated or not.
"""
location = unquote_slashes(usage_id)
# Check parameters and fail fast if there's a problem
if not Location.is_valid(location):
raise Http404("Invalid location")
# Check submitted files
files = request.FILES or {}
error_msg = _check_files_limits(files)
if error_msg:
return HttpResponse(json.dumps({'success': error_msg}))
try:
descriptor = modulestore().get_instance(course_id, location)
except ItemNotFoundError:
log.warn(
"Invalid location for course id {course_id}: {location}".format(
course_id=course_id, location=location))
raise Http404
field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
course_id, user, descriptor)
instance = get_module(user,
request,
location,
field_data_cache,
course_id,
grade_bucket_type='ajax')
if instance is None:
# Either permissions just changed, or someone is trying to be clever
# and load something they shouldn't have access to.
log.debug("No module %s for user %s -- access denied?", location, user)
raise Http404
req = django_to_webob_request(request)
try:
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r",
instance, handler)
raise Http404
# If we can't find the module, respond with a 404
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
# For XModule-specific errors, we log the error and respond with an error message
except ProcessingError as err:
log.warning("Module encountered an error while processing AJAX call",
exc_info=True)
return JsonResponse(object={'success': err.args[0]}, status=200)
# If any other error occurred, re-raise it to trigger a 500 response
except Exception:
log.exception("error executing xblock handler")
raise
return webob_to_django_response(resp)
def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix, course=None):
"""
Invoke an XBlock handler, either authenticated or not.
Arguments:
request (HttpRequest): the current request
course_id (str): A string of the form org/course/run
usage_id (str): A string of the form i4x://org/course/category/name@revision
handler (str): The name of the handler to invoke
suffix (str): The suffix to pass to the handler when invoked
"""
# Check submitted files
files = request.FILES or {}
error_msg = _check_files_limits(files)
if error_msg:
return JsonResponse({'success': error_msg}, status=413)
# Make a CourseKey from the course_id, raising a 404 upon parse error.
try:
course_key = CourseKey.from_string(course_id)
except InvalidKeyError:
raise Http404
set_custom_metrics_for_course_key(course_key)
with modulestore().bulk_operations(course_key):
instance, tracking_context = get_module_by_usage_id(request, course_id, usage_id, course=course)
# Name the transaction so that we can view XBlock handlers separately in
# New Relic. The suffix is necessary for XModule handlers because the
# "handler" in those cases is always just "xmodule_handler".
nr_tx_name = "{}.{}".format(instance.__class__.__name__, handler)
nr_tx_name += "/{}".format(suffix) if (suffix and handler == "xmodule_handler") else ""
set_monitoring_transaction_name(nr_tx_name, group="Python/XBlock/Handler")
tracking_context_name = 'module_callback_handler'
req = django_to_webob_request(request)
try:
with tracker.get_tracker().context(tracking_context_name, tracking_context):
resp = instance.handle(handler, req, suffix)
if suffix == 'problem_check' \
and course \
and getattr(course, 'entrance_exam_enabled', False) \
and getattr(instance, 'in_entrance_exam', False):
ee_data = {'entrance_exam_passed': user_has_passed_entrance_exam(request.user, course)}
resp = append_data_to_webob_response(resp, ee_data)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
# If we can't find the module, respond with a 404
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
# For XModule-specific errors, we log the error and respond with an error message
except ProcessingError as err:
log.warning("Module encountered an error while processing AJAX call",
exc_info=True)
return JsonResponse({'success': err.args[0]}, status=200)
# If any other error occurred, re-raise it to trigger a 500 response
except Exception:
log.exception("error executing xblock handler")
raise
return webob_to_django_response(resp)
def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix,
user):
"""
Invoke an XBlock handler, either authenticated or not.
Arguments:
request (HttpRequest): the current request
course_id (str): A string of the form org/course/run
usage_id (str): A string of the form i4x://org/course/category/name@revision
handler (str): The name of the handler to invoke
suffix (str): The suffix to pass to the handler when invoked
user (User): The currently logged in user
"""
try:
course_id = SlashSeparatedCourseKey.from_deprecated_string(course_id)
usage_key = course_id.make_usage_key_from_deprecated_string(
unquote_slashes(usage_id))
except InvalidKeyError:
raise Http404("Invalid location")
# Check submitted files
files = request.FILES or {}
error_msg = _check_files_limits(files)
if error_msg:
return HttpResponse(json.dumps({'success': error_msg}))
try:
descriptor = modulestore().get_item(usage_key)
except ItemNotFoundError:
log.warn(
"Invalid location for course id {course_id}: {usage_key}".format(
course_id=usage_key.course_key, usage_key=usage_key))
raise Http404
tracking_context_name = 'module_callback_handler'
tracking_context = {
'module': {
'display_name': descriptor.display_name_with_default,
}
}
field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
course_id, user, descriptor)
instance = get_module(user,
request,
usage_key,
field_data_cache,
grade_bucket_type='ajax')
if instance is None:
# Either permissions just changed, or someone is trying to be clever
# and load something they shouldn't have access to.
log.debug("No module %s for user %s -- access denied?", usage_key,
user)
raise Http404
req = django_to_webob_request(request)
try:
with tracker.get_tracker().context(tracking_context_name,
tracking_context):
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r",
instance, handler)
raise Http404
# If we can't find the module, respond with a 404
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
# For XModule-specific errors, we log the error and respond with an error message
except ProcessingError as err:
log.warning("Module encountered an error while processing AJAX call",
exc_info=True)
return JsonResponse(object={'success': err.args[0]}, status=200)
# If any other error occurred, re-raise it to trigger a 500 response
except Exception:
log.exception("error executing xblock handler")
raise
return webob_to_django_response(resp)
def handle(self, block, handler_name, request, suffix=''):
# Convert Django request to webob
request = django_to_webob_request(request)
return super(Runtime, self).handle(block, handler_name, request, suffix=suffix)
def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix, course=None):
"""
Invoke an XBlock handler, either authenticated or not.
Arguments:
request (HttpRequest): the current request
course_id (str): A string of the form org/course/run
usage_id (str): A string of the form i4x://org/course/category/name@revision
handler (str): The name of the handler to invoke
suffix (str): The suffix to pass to the handler when invoked
"""
# Check submitted files
files = request.FILES or {}
error_msg = _check_files_limits(files)
if error_msg:
return JsonResponse({'success': error_msg}, status=413)
# Make a CourseKey from the course_id, raising a 404 upon parse error.
try:
course_key = CourseKey.from_string(course_id)
except InvalidKeyError:
raise Http404
# Gather metrics for New Relic so we can slice data in New Relic Insights
newrelic.agent.add_custom_parameter('course_id', unicode(course_key))
newrelic.agent.add_custom_parameter('org', unicode(course_key.org))
with modulestore().bulk_operations(course_key):
instance, tracking_context = get_module_by_usage_id(request, course_id, usage_id, course=course)
# Name the transaction so that we can view XBlock handlers separately in
# New Relic. The suffix is necessary for XModule handlers because the
# "handler" in those cases is always just "xmodule_handler".
nr_tx_name = "{}.{}".format(instance.__class__.__name__, handler)
nr_tx_name += "/{}".format(suffix) if (suffix and handler == "xmodule_handler") else ""
newrelic.agent.set_transaction_name(nr_tx_name, group="Python/XBlock/Handler")
tracking_context_name = 'module_callback_handler'
req = django_to_webob_request(request)
try:
with tracker.get_tracker().context(tracking_context_name, tracking_context):
resp = instance.handle(handler, req, suffix)
if suffix == 'problem_check' \
and course \
and getattr(course, 'entrance_exam_enabled', False) \
and getattr(instance, 'in_entrance_exam', False):
ee_data = {'entrance_exam_passed': user_has_passed_entrance_exam(request, course)}
resp = append_data_to_webob_response(resp, ee_data)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
# If we can't find the module, respond with a 404
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
# For XModule-specific errors, we log the error and respond with an error message
except ProcessingError as err:
log.warning("Module encountered an error while processing AJAX call",
exc_info=True)
return JsonResponse({'success': err.args[0]}, status=200)
# If any other error occurred, re-raise it to trigger a 500 response
except Exception:
log.exception("error executing xblock handler")
raise
return webob_to_django_response(resp)
def _invoke_xblock_handler(request, course_id, usage_id, handler, suffix, user):
"""
Invoke an XBlock handler, either authenticated or not.
Arguments:
request (HttpRequest): the current request
course_id (str): A string of the form org/course/run
usage_id (str): A string of the form i4x://org/course/category/name@revision
handler (str): The name of the handler to invoke
suffix (str): The suffix to pass to the handler when invoked
user (User): The currently logged in user
"""
try:
course_id = SlashSeparatedCourseKey.from_deprecated_string(course_id)
usage_key = course_id.make_usage_key_from_deprecated_string(unquote_slashes(usage_id))
except InvalidKeyError:
raise Http404("Invalid location")
# Check submitted files
files = request.FILES or {}
error_msg = _check_files_limits(files)
if error_msg:
return HttpResponse(json.dumps({'success': error_msg}))
try:
descriptor = modulestore().get_item(usage_key)
except ItemNotFoundError:
log.warn(
"Invalid location for course id {course_id}: {usage_key}".format(
course_id=usage_key.course_key,
usage_key=usage_key
)
)
raise Http404
tracking_context_name = 'module_callback_handler'
tracking_context = {
'module': {
'display_name': descriptor.display_name_with_default,
}
}
field_data_cache = FieldDataCache.cache_for_descriptor_descendents(
course_id,
user,
descriptor
)
instance = get_module(user, request, usage_key, field_data_cache, grade_bucket_type='ajax')
if instance is None:
# Either permissions just changed, or someone is trying to be clever
# and load something they shouldn't have access to.
log.debug("No module %s for user %s -- access denied?", usage_key, user)
raise Http404
req = django_to_webob_request(request)
try:
with tracker.get_tracker().context(tracking_context_name, tracking_context):
resp = instance.handle(handler, req, suffix)
except NoSuchHandlerError:
log.exception("XBlock %s attempted to access missing handler %r", instance, handler)
raise Http404
# If we can't find the module, respond with a 404
except NotFoundError:
log.exception("Module indicating to user that request doesn't exist")
raise Http404
# For XModule-specific errors, we log the error and respond with an error message
except ProcessingError as err:
log.warning("Module encountered an error while processing AJAX call",
exc_info=True)
return JsonResponse(object={'success': err.args[0]}, status=200)
# If any other error occurred, re-raise it to trigger a 500 response
except Exception:
log.exception("error executing xblock handler")
raise
return webob_to_django_response(resp)