Ejemplo n.º 1
0
def get_module_system_for_user(user, field_data_cache,
                               # Arguments preceding this comment have user binding, those following don't
                               descriptor, course_id, track_function, xqueue_callback_url_prefix,
                               position=None, wrap_xmodule_display=True, grade_bucket_type=None,
                               static_asset_path='', user_location=None):
    """
    Helper function that returns a module system and student_data bound to a user and a descriptor.

    The purpose of this function is to factor out everywhere a user is implicitly bound when creating a module,
    to allow an existing module to be re-bound to a user.  Most of the user bindings happen when creating the
    closures that feed the instantiation of ModuleSystem.

    The arguments fall into two categories: those that have explicit or implicit user binding, which are user
    and field_data_cache, and those don't and are just present so that ModuleSystem can be instantiated, which
    are all the other arguments.  Ultimately, this isn't too different than how get_module_for_descriptor_internal
    was before refactoring.

    Arguments:
        see arguments for get_module()

    Returns:
        (LmsModuleSystem, KvsFieldData):  (module system, student_data) bound to, primarily, the user and descriptor
    """
    student_data = KvsFieldData(DjangoKeyValueStore(field_data_cache))

    def make_xqueue_callback(dispatch='score_update'):
        # Fully qualified callback URL for external queueing system
        relative_xqueue_callback_url = reverse(
            'xqueue_callback',
            kwargs=dict(
                course_id=course_id.to_deprecated_string(),
                userid=str(user.id),
                mod_id=descriptor.location.to_deprecated_string(),
                dispatch=dispatch
            ),
        )
        return xqueue_callback_url_prefix + relative_xqueue_callback_url

    # Default queuename is course-specific and is derived from the course that
    #   contains the current module.
    # TODO: Queuename should be derived from 'course_settings.json' of each course
    xqueue_default_queuename = descriptor.location.org + '-' + descriptor.location.course

    xqueue = {
        'interface': XQUEUE_INTERFACE,
        'construct_callback': make_xqueue_callback,
        'default_queuename': xqueue_default_queuename.replace(' ', '_'),
        'waittime': settings.XQUEUE_WAITTIME_BETWEEN_REQUESTS
    }

    # This is a hacky way to pass settings to the combined open ended xmodule
    # It needs an S3 interface to upload images to S3
    # It needs the open ended grading interface in order to get peer grading to be done
    # this first checks to see if the descriptor is the correct one, and only sends settings if it is

    # Get descriptor metadata fields indicating needs for various settings
    needs_open_ended_interface = getattr(descriptor, "needs_open_ended_interface", False)
    needs_s3_interface = getattr(descriptor, "needs_s3_interface", False)

    # Initialize interfaces to None
    open_ended_grading_interface = None
    s3_interface = None

    # Create interfaces if needed
    if needs_open_ended_interface:
        open_ended_grading_interface = settings.OPEN_ENDED_GRADING_INTERFACE
        open_ended_grading_interface['mock_peer_grading'] = settings.MOCK_PEER_GRADING
        open_ended_grading_interface['mock_staff_grading'] = settings.MOCK_STAFF_GRADING
    if needs_s3_interface:
        s3_interface = {
            'access_key': getattr(settings, 'AWS_ACCESS_KEY_ID', ''),
            'secret_access_key': getattr(settings, 'AWS_SECRET_ACCESS_KEY', ''),
            'storage_bucket_name': getattr(settings, 'AWS_STORAGE_BUCKET_NAME', 'openended')
        }

    def inner_get_module(descriptor):
        """
        Delegate to get_module_for_descriptor_internal() with all values except `descriptor` set.

        Because it does an access check, it may return None.
        """
        # TODO: fix this so that make_xqueue_callback uses the descriptor passed into
        # inner_get_module, not the parent's callback.  Add it as an argument....
        return get_module_for_descriptor_internal(user, descriptor, field_data_cache, course_id,
                                                  track_function, make_xqueue_callback,
                                                  position, wrap_xmodule_display, grade_bucket_type,
                                                  static_asset_path, user_location)

    def handle_grade_event(block, event_type, event):
        user_id = event.get('user_id', user.id)

        # Construct the key for the module
        key = KeyValueStore.Key(
            scope=Scope.user_state,
            user_id=user_id,
            block_scope_id=descriptor.location,
            field_name='grade'
        )

        student_module = field_data_cache.find_or_create(key)
        # Update the grades
        student_module.grade = event.get('value')
        student_module.max_grade = event.get('max_value')
        # Save all changes to the underlying KeyValueStore
        student_module.save()

        # Bin score into range and increment stats
        score_bucket = get_score_bucket(student_module.grade, student_module.max_grade)

        tags = [
            u"org:{}".format(course_id.org),
            u"course:{}".format(course_id),
            u"score_bucket:{0}".format(score_bucket)
        ]

        if grade_bucket_type is not None:
            tags.append('type:%s' % grade_bucket_type)

        dog_stats_api.increment("lms.courseware.question_answered", tags=tags)

    def publish(block, event_type, event):
        """A function that allows XModules to publish events."""
        if event_type == 'grade':
            handle_grade_event(block, event_type, event)
        else:
            track_function(event_type, event)

    def rebind_noauth_module_to_user(module, real_user):
        """
        A function that allows a module to get re-bound to a real user if it was previously bound to an AnonymousUser.

        Will only work within a module bound to an AnonymousUser, e.g. one that's instantiated by the noauth_handler.

        Arguments:
            module (any xblock type):  the module to rebind
            real_user (django.contrib.auth.models.User):  the user to bind to

        Returns:
            nothing (but the side effect is that module is re-bound to real_user)
        """
        if user.is_authenticated():
            err_msg = ("rebind_noauth_module_to_user can only be called from a module bound to "
                       "an anonymous user")
            log.error(err_msg)
            raise LmsModuleRenderError(err_msg)

        field_data_cache_real_user = FieldDataCache.cache_for_descriptor_descendents(
            course_id,
            real_user,
            module.descriptor
        )

        (inner_system, inner_student_data) = get_module_system_for_user(
            real_user, field_data_cache_real_user,  # These have implicit user bindings, rest of args considered not to
            module.descriptor, course_id, track_function, xqueue_callback_url_prefix, position, wrap_xmodule_display,
            grade_bucket_type, static_asset_path, user_location
        )
        # rebinds module to a different student.  We'll change system, student_data, and scope_ids
        module.descriptor.bind_for_student(
            inner_system,
            LmsFieldData(module.descriptor._field_data, inner_student_data)  # pylint: disable=protected-access
        )
        module.descriptor.scope_ids = (
            module.descriptor.scope_ids._replace(user_id=real_user.id)  # pylint: disable=protected-access
        )
        module.scope_ids = module.descriptor.scope_ids  # this is needed b/c NamedTuples are immutable
        # now bind the module to the new ModuleSystem instance and vice-versa
        module.runtime = inner_system
        inner_system.xmodule_instance = module

    # Build a list of wrapping functions that will be applied in order
    # to the Fragment content coming out of the xblocks that are about to be rendered.
    block_wrappers = []

    # Wrap the output display in a single div to allow for the XModule
    # javascript to be bound correctly
    if wrap_xmodule_display is True:
        block_wrappers.append(partial(
            wrap_xblock, 'LmsRuntime',
            extra_data={'course-id': course_id.to_deprecated_string()},
            usage_id_serializer=lambda usage_id: quote_slashes(usage_id.to_deprecated_string())
        ))

    # TODO (cpennington): When modules are shared between courses, the static
    # prefix is going to have to be specific to the module, not the directory
    # that the xml was loaded from

    # Rewrite urls beginning in /static to point to course-specific content
    block_wrappers.append(partial(
        replace_static_urls,
        getattr(descriptor, 'data_dir', None),
        course_id=course_id,
        static_asset_path=static_asset_path or descriptor.static_asset_path
    ))

    # Allow URLs of the form '/course/' refer to the root of multicourse directory
    #   hierarchy of this course
    block_wrappers.append(partial(replace_course_urls, course_id))

    # this will rewrite intra-courseware links (/jump_to_id/<id>). This format
    # is an improvement over the /course/... format for studio authored courses,
    # because it is agnostic to course-hierarchy.
    # NOTE: module_id is empty string here. The 'module_id' will get assigned in the replacement
    # function, we just need to specify something to get the reverse() to work.
    block_wrappers.append(partial(
        replace_jump_to_id_urls,
        course_id,
        reverse('jump_to_id', kwargs={'course_id': course_id.to_deprecated_string(), 'module_id': ''}),
    ))

    if settings.FEATURES.get('DISPLAY_DEBUG_INFO_TO_STAFF'):
        if has_access(user, 'staff', descriptor, course_id):
            has_instructor_access = has_access(user, 'instructor', descriptor, course_id)
            block_wrappers.append(partial(add_staff_markup, user, has_instructor_access))

    # These modules store data using the anonymous_student_id as a key.
    # To prevent loss of data, we will continue to provide old modules with
    # the per-student anonymized id (as we have in the past),
    # while giving selected modules a per-course anonymized id.
    # As we have the time to manually test more modules, we can add to the list
    # of modules that get the per-course anonymized id.
    is_pure_xblock = isinstance(descriptor, XBlock) and not isinstance(descriptor, XModuleDescriptor)
    module_class = getattr(descriptor, 'module_class', None)
    is_lti_module = not is_pure_xblock and issubclass(module_class, LTIModule)
    if is_pure_xblock or is_lti_module:
        anonymous_student_id = anonymous_id_for_user(user, course_id)
    else:
        anonymous_student_id = anonymous_id_for_user(user, None)

    system = LmsModuleSystem(
        track_function=track_function,
        render_template=render_to_string,
        static_url=settings.STATIC_URL,
        xqueue=xqueue,
        # TODO (cpennington): Figure out how to share info between systems
        filestore=descriptor.runtime.resources_fs,
        get_module=inner_get_module,
        user=user,
        debug=settings.DEBUG,
        hostname=settings.SITE_NAME,
        # TODO (cpennington): This should be removed when all html from
        # a module is coming through get_html and is therefore covered
        # by the replace_static_urls code below
        replace_urls=partial(
            static_replace.replace_static_urls,
            data_directory=getattr(descriptor, 'data_dir', None),
            course_id=course_id,
            static_asset_path=static_asset_path or descriptor.static_asset_path,
        ),
        replace_course_urls=partial(
            static_replace.replace_course_urls,
            course_key=course_id
        ),
        replace_jump_to_id_urls=partial(
            static_replace.replace_jump_to_id_urls,
            course_id=course_id,
            jump_to_id_base_url=reverse('jump_to_id', kwargs={'course_id': course_id.to_deprecated_string(), 'module_id': ''})
        ),
        node_path=settings.NODE_PATH,
        publish=publish,
        anonymous_student_id=anonymous_student_id,
        course_id=course_id,
        open_ended_grading_interface=open_ended_grading_interface,
        s3_interface=s3_interface,
        cache=cache,
        can_execute_unsafe_code=(lambda: can_execute_unsafe_code(course_id)),
        # TODO: When we merge the descriptor and module systems, we can stop reaching into the mixologist (cpennington)
        mixins=descriptor.runtime.mixologist._mixins,  # pylint: disable=protected-access
        wrappers=block_wrappers,
        get_real_user=user_by_anonymous_id,
        services={
            'i18n': ModuleI18nService(),
        },
        get_user_role=lambda: get_user_role(user, course_id),
        descriptor_runtime=descriptor.runtime,
        rebind_noauth_module_to_user=rebind_noauth_module_to_user,
        user_location=user_location,
    )

    # pass position specified in URL to module through ModuleSystem
    system.set('position', position)
    if settings.FEATURES.get('ENABLE_PSYCHOMETRICS'):
        system.set(
            'psychometrics_handler',  # set callback for updating PsychometricsData
            make_psychometrics_data_update_handler(course_id, user, descriptor.location)
        )

    system.set(u'user_is_staff', has_access(user, u'staff', descriptor.location, course_id))
    system.set(u'user_is_admin', has_access(user, u'staff', 'global'))

    # make an ErrorDescriptor -- assuming that the descriptor's system is ok
    if has_access(user, u'staff', descriptor.location, course_id):
        system.error_descriptor_class = ErrorDescriptor
    else:
        system.error_descriptor_class = NonStaffErrorDescriptor

    return system, student_data
Ejemplo n.º 2
0
def get_module_for_descriptor_internal(user,
                                       descriptor,
                                       field_data_cache,
                                       course_id,
                                       track_function,
                                       xqueue_callback_url_prefix,
                                       position=None,
                                       wrap_xmodule_display=True,
                                       grade_bucket_type=None,
                                       static_asset_path=''):
    """
    Actually implement get_module, without requiring a request.

    See get_module() docstring for further details.
    """

    # Short circuit--if the user shouldn't have access, bail without doing any work
    if not has_access(user, descriptor, 'load', course_id):
        return None

    student_data = KvsFieldData(DjangoKeyValueStore(field_data_cache))
    descriptor._field_data = LmsFieldData(descriptor._field_data, student_data)

    def make_xqueue_callback(dispatch='score_update'):
        # Fully qualified callback URL for external queueing system
        relative_xqueue_callback_url = reverse(
            'xqueue_callback',
            kwargs=dict(course_id=course_id,
                        userid=str(user.id),
                        mod_id=descriptor.location.url(),
                        dispatch=dispatch),
        )
        return xqueue_callback_url_prefix + relative_xqueue_callback_url

    # Default queuename is course-specific and is derived from the course that
    #   contains the current module.
    # TODO: Queuename should be derived from 'course_settings.json' of each course
    xqueue_default_queuename = descriptor.location.org + '-' + descriptor.location.course

    xqueue = {
        'interface': xqueue_interface,
        'construct_callback': make_xqueue_callback,
        'default_queuename': xqueue_default_queuename.replace(' ', '_'),
        'waittime': settings.XQUEUE_WAITTIME_BETWEEN_REQUESTS
    }

    # This is a hacky way to pass settings to the combined open ended xmodule
    # It needs an S3 interface to upload images to S3
    # It needs the open ended grading interface in order to get peer grading to be done
    # this first checks to see if the descriptor is the correct one, and only sends settings if it is

    # Get descriptor metadata fields indicating needs for various settings
    needs_open_ended_interface = getattr(descriptor,
                                         "needs_open_ended_interface", False)
    needs_s3_interface = getattr(descriptor, "needs_s3_interface", False)

    # Initialize interfaces to None
    open_ended_grading_interface = None
    s3_interface = None

    # Create interfaces if needed
    if needs_open_ended_interface:
        open_ended_grading_interface = settings.OPEN_ENDED_GRADING_INTERFACE
        open_ended_grading_interface[
            'mock_peer_grading'] = settings.MOCK_PEER_GRADING
        open_ended_grading_interface[
            'mock_staff_grading'] = settings.MOCK_STAFF_GRADING
    if needs_s3_interface:
        s3_interface = {
            'access_key':
            getattr(settings, 'AWS_ACCESS_KEY_ID', ''),
            'secret_access_key':
            getattr(settings, 'AWS_SECRET_ACCESS_KEY', ''),
            'storage_bucket_name':
            getattr(settings, 'AWS_STORAGE_BUCKET_NAME', 'openended')
        }

    def inner_get_module(descriptor):
        """
        Delegate to get_module_for_descriptor_internal() with all values except `descriptor` set.

        Because it does an access check, it may return None.
        """
        # TODO: fix this so that make_xqueue_callback uses the descriptor passed into
        # inner_get_module, not the parent's callback.  Add it as an argument....
        return get_module_for_descriptor_internal(
            user, descriptor, field_data_cache, course_id, track_function,
            make_xqueue_callback, position, wrap_xmodule_display,
            grade_bucket_type, static_asset_path)

    def publish(event, custom_user=None):
        """A function that allows XModules to publish events. This only supports grade changes right now."""
        if event.get('event_name') != 'grade':
            return

        if custom_user:
            user_id = custom_user.id
        else:
            user_id = user.id

        # Construct the key for the module
        key = KeyValueStore.Key(scope=Scope.user_state,
                                user_id=user_id,
                                block_scope_id=descriptor.location,
                                field_name='grade')

        student_module = field_data_cache.find_or_create(key)
        # Update the grades
        student_module.grade = event.get('value')
        student_module.max_grade = event.get('max_value')
        # Save all changes to the underlying KeyValueStore
        student_module.save()

        # Bin score into range and increment stats
        score_bucket = get_score_bucket(student_module.grade,
                                        student_module.max_grade)
        org, course_num, run = course_id.split("/")

        tags = [
            "org:{0}".format(org), "course:{0}".format(course_num),
            "run:{0}".format(run), "score_bucket:{0}".format(score_bucket)
        ]

        if grade_bucket_type is not None:
            tags.append('type:%s' % grade_bucket_type)

        dog_stats_api.increment("lms.courseware.question_answered", tags=tags)

    # Build a list of wrapping functions that will be applied in order
    # to the Fragment content coming out of the xblocks that are about to be rendered.
    block_wrappers = []

    # Wrap the output display in a single div to allow for the XModule
    # javascript to be bound correctly
    if wrap_xmodule_display is True:
        block_wrappers.append(
            partial(wrap_xblock, partial(handler_prefix, course_id)))

    # TODO (cpennington): When modules are shared between courses, the static
    # prefix is going to have to be specific to the module, not the directory
    # that the xml was loaded from

    # Rewrite urls beginning in /static to point to course-specific content
    block_wrappers.append(
        partial(replace_static_urls,
                getattr(descriptor, 'data_dir', None),
                course_id=course_id,
                static_asset_path=static_asset_path
                or descriptor.static_asset_path))

    # Allow URLs of the form '/course/' refer to the root of multicourse directory
    #   hierarchy of this course
    block_wrappers.append(partial(replace_course_urls, course_id))

    # this will rewrite intra-courseware links (/jump_to_id/<id>). This format
    # is an improvement over the /course/... format for studio authored courses,
    # because it is agnostic to course-hierarchy.
    # NOTE: module_id is empty string here. The 'module_id' will get assigned in the replacement
    # function, we just need to specify something to get the reverse() to work.
    block_wrappers.append(
        partial(
            replace_jump_to_id_urls,
            course_id,
            reverse('jump_to_id',
                    kwargs={
                        'course_id': course_id,
                        'module_id': ''
                    }),
        ))

    if settings.FEATURES.get('DISPLAY_HISTOGRAMS_TO_STAFF'):
        if has_access(user, descriptor, 'staff', course_id):
            block_wrappers.append(partial(add_histogram, user))

    # These modules store data using the anonymous_student_id as a key.
    # To prevent loss of data, we will continue to provide old modules with
    # the per-student anonymized id (as we have in the past),
    # while giving selected modules a per-course anonymized id.
    # As we have the time to manually test more modules, we can add to the list
    # of modules that get the per-course anonymized id.
    is_pure_xblock = isinstance(
        descriptor, XBlock) and not isinstance(descriptor, XModuleDescriptor)
    is_lti_module = not is_pure_xblock and issubclass(descriptor.module_class,
                                                      LTIModule)
    if is_pure_xblock or is_lti_module:
        anonymous_student_id = anonymous_id_for_user(user, course_id)
    else:
        anonymous_student_id = anonymous_id_for_user(user, '')

    system = LmsModuleSystem(
        track_function=track_function,
        render_template=render_to_string,
        static_url=settings.STATIC_URL,
        xqueue=xqueue,
        # TODO (cpennington): Figure out how to share info between systems
        filestore=descriptor.runtime.resources_fs,
        get_module=inner_get_module,
        user=user,
        debug=settings.DEBUG,
        hostname=settings.SITE_NAME,
        # TODO (cpennington): This should be removed when all html from
        # a module is coming through get_html and is therefore covered
        # by the replace_static_urls code below
        replace_urls=partial(
            static_replace.replace_static_urls,
            data_directory=getattr(descriptor, 'data_dir', None),
            course_id=course_id,
            static_asset_path=static_asset_path
            or descriptor.static_asset_path,
        ),
        replace_course_urls=partial(static_replace.replace_course_urls,
                                    course_id=course_id),
        replace_jump_to_id_urls=partial(static_replace.replace_jump_to_id_urls,
                                        course_id=course_id,
                                        jump_to_id_base_url=reverse(
                                            'jump_to_id',
                                            kwargs={
                                                'course_id': course_id,
                                                'module_id': ''
                                            })),
        node_path=settings.NODE_PATH,
        publish=publish,
        anonymous_student_id=anonymous_student_id,
        course_id=course_id,
        open_ended_grading_interface=open_ended_grading_interface,
        s3_interface=s3_interface,
        cache=cache,
        can_execute_unsafe_code=(lambda: can_execute_unsafe_code(course_id)),
        # TODO: When we merge the descriptor and module systems, we can stop reaching into the mixologist (cpennington)
        mixins=descriptor.runtime.mixologist._mixins,  # pylint: disable=protected-access
        wrappers=block_wrappers,
        get_real_user=user_by_anonymous_id,
        services={
            # django.utils.translation implements the gettext.Translations
            # interface (it has ugettext, ungettext, etc), so we can use it
            # directly as the runtime i18n service.
            'i18n': django.utils.translation,
        },
    )

    # pass position specified in URL to module through ModuleSystem
    system.set('position', position)
    if settings.FEATURES.get('ENABLE_PSYCHOMETRICS'):
        system.set(
            'psychometrics_handler',  # set callback for updating PsychometricsData
            make_psychometrics_data_update_handler(course_id, user,
                                                   descriptor.location.url()))

    system.set('user_is_staff',
               has_access(user, descriptor.location, 'staff', course_id))

    # make an ErrorDescriptor -- assuming that the descriptor's system is ok
    if has_access(user, descriptor.location, 'staff', course_id):
        system.error_descriptor_class = ErrorDescriptor
    else:
        system.error_descriptor_class = NonStaffErrorDescriptor

    descriptor.xmodule_runtime = system
    descriptor.scope_ids = descriptor.scope_ids._replace(user_id=user.id)
    return descriptor
Ejemplo n.º 3
0
def get_module_for_descriptor_internal(user, descriptor, field_data_cache, course_id,
                                       track_function, xqueue_callback_url_prefix,
                                       position=None, wrap_xmodule_display=True, grade_bucket_type=None,
                                       static_asset_path=''):
    """
    Actually implement get_module, without requiring a request.

    See get_module() docstring for further details.
    """

    # Do not check access when it's a noauth request.
    if getattr(user, 'known', True):
        # Short circuit--if the user shouldn't have access, bail without doing any work
        if not has_access(user, descriptor, 'load', course_id):
            return None

    student_data = KvsFieldData(DjangoKeyValueStore(field_data_cache))
    descriptor._field_data = LmsFieldData(descriptor._field_data, student_data)


    def make_xqueue_callback(dispatch='score_update'):
        # Fully qualified callback URL for external queueing system
        relative_xqueue_callback_url = reverse(
            'xqueue_callback',
            kwargs=dict(
                course_id=course_id,
                userid=str(user.id),
                mod_id=descriptor.location.url(),
                dispatch=dispatch
            ),
        )
        return xqueue_callback_url_prefix + relative_xqueue_callback_url

    # Default queuename is course-specific and is derived from the course that
    #   contains the current module.
    # TODO: Queuename should be derived from 'course_settings.json' of each course
    xqueue_default_queuename = descriptor.location.org + '-' + descriptor.location.course

    xqueue = {
        'interface': xqueue_interface,
        'construct_callback': make_xqueue_callback,
        'default_queuename': xqueue_default_queuename.replace(' ', '_'),
        'waittime': settings.XQUEUE_WAITTIME_BETWEEN_REQUESTS
    }

    # This is a hacky way to pass settings to the combined open ended xmodule
    # It needs an S3 interface to upload images to S3
    # It needs the open ended grading interface in order to get peer grading to be done
    # this first checks to see if the descriptor is the correct one, and only sends settings if it is

    # Get descriptor metadata fields indicating needs for various settings
    needs_open_ended_interface = getattr(descriptor, "needs_open_ended_interface", False)
    needs_s3_interface = getattr(descriptor, "needs_s3_interface", False)

    # Initialize interfaces to None
    open_ended_grading_interface = None
    s3_interface = None

    # Create interfaces if needed
    if needs_open_ended_interface:
        open_ended_grading_interface = settings.OPEN_ENDED_GRADING_INTERFACE
        open_ended_grading_interface['mock_peer_grading'] = settings.MOCK_PEER_GRADING
        open_ended_grading_interface['mock_staff_grading'] = settings.MOCK_STAFF_GRADING
    if needs_s3_interface:
        s3_interface = {
            'access_key': getattr(settings, 'AWS_ACCESS_KEY_ID', ''),
            'secret_access_key': getattr(settings, 'AWS_SECRET_ACCESS_KEY', ''),
            'storage_bucket_name': getattr(settings, 'AWS_STORAGE_BUCKET_NAME', 'openended')
        }

    def inner_get_module(descriptor):
        """
        Delegate to get_module_for_descriptor_internal() with all values except `descriptor` set.

        Because it does an access check, it may return None.
        """
        # TODO: fix this so that make_xqueue_callback uses the descriptor passed into
        # inner_get_module, not the parent's callback.  Add it as an argument....
        return get_module_for_descriptor_internal(user, descriptor, field_data_cache, course_id,
                                                  track_function, make_xqueue_callback,
                                                  position, wrap_xmodule_display, grade_bucket_type,
                                                  static_asset_path)

    def publish(block, event, custom_user=None):
        """A function that allows XModules to publish events. This only supports grade changes right now."""
        if event.get('event_name') != 'grade':
            return

        if custom_user:
            user_id = custom_user.id
        else:
            user_id = user.id

        # Construct the key for the module
        key = KeyValueStore.Key(
            scope=Scope.user_state,
            user_id=user_id,
            block_scope_id=descriptor.location,
            field_name='grade'
        )

        student_module = field_data_cache.find_or_create(key)
        # Update the grades
        student_module.grade = event.get('value')
        student_module.max_grade = event.get('max_value')
        # Save all changes to the underlying KeyValueStore
        student_module.save()

        # Bin score into range and increment stats
        score_bucket = get_score_bucket(student_module.grade, student_module.max_grade)
        org, course_num, run = course_id.split("/")

        tags = [
            u"org:{0}".format(org),
            u"course:{0}".format(course_num),
            u"run:{0}".format(run),
            u"score_bucket:{0}".format(score_bucket)
        ]

        if grade_bucket_type is not None:
            tags.append('type:%s' % grade_bucket_type)

        dog_stats_api.increment("lms.courseware.question_answered", tags=tags)

    # Build a list of wrapping functions that will be applied in order
    # to the Fragment content coming out of the xblocks that are about to be rendered.
    block_wrappers = []

    # Wrap the output display in a single div to allow for the XModule
    # javascript to be bound correctly
    if wrap_xmodule_display is True:
        block_wrappers.append(partial(wrap_xblock, 'LmsRuntime', extra_data={'course-id': course_id}))

    # TODO (cpennington): When modules are shared between courses, the static
    # prefix is going to have to be specific to the module, not the directory
    # that the xml was loaded from

    # Rewrite urls beginning in /static to point to course-specific content
    block_wrappers.append(partial(
        replace_static_urls,
        getattr(descriptor, 'data_dir', None),
        course_id=course_id,
        static_asset_path=static_asset_path or descriptor.static_asset_path
    ))

    # Allow URLs of the form '/course/' refer to the root of multicourse directory
    #   hierarchy of this course
    block_wrappers.append(partial(replace_course_urls, course_id))

    # this will rewrite intra-courseware links (/jump_to_id/<id>). This format
    # is an improvement over the /course/... format for studio authored courses,
    # because it is agnostic to course-hierarchy.
    # NOTE: module_id is empty string here. The 'module_id' will get assigned in the replacement
    # function, we just need to specify something to get the reverse() to work.
    block_wrappers.append(partial(
        replace_jump_to_id_urls,
        course_id,
        reverse('jump_to_id', kwargs={'course_id': course_id, 'module_id': ''}),
    ))

    if settings.FEATURES.get('DISPLAY_HISTOGRAMS_TO_STAFF'):
        if has_access(user, descriptor, 'staff', course_id):
            block_wrappers.append(partial(add_histogram, user))

    # These modules store data using the anonymous_student_id as a key.
    # To prevent loss of data, we will continue to provide old modules with
    # the per-student anonymized id (as we have in the past),
    # while giving selected modules a per-course anonymized id.
    # As we have the time to manually test more modules, we can add to the list
    # of modules that get the per-course anonymized id.
    is_pure_xblock = isinstance(descriptor, XBlock) and not isinstance(descriptor, XModuleDescriptor)
    module_class = getattr(descriptor, 'module_class', None)
    is_lti_module = not is_pure_xblock and issubclass(module_class, LTIModule)
    if is_pure_xblock or is_lti_module:
        anonymous_student_id = anonymous_id_for_user(user, course_id)
    else:
        anonymous_student_id = anonymous_id_for_user(user, '')

    system = LmsModuleSystem(
        track_function=track_function,
        render_template=render_to_string,
        static_url=settings.STATIC_URL,
        xqueue=xqueue,
        # TODO (cpennington): Figure out how to share info between systems
        filestore=descriptor.runtime.resources_fs,
        get_module=inner_get_module,
        user=user,
        debug=settings.DEBUG,
        hostname=settings.SITE_NAME,
        # TODO (cpennington): This should be removed when all html from
        # a module is coming through get_html and is therefore covered
        # by the replace_static_urls code below
        replace_urls=partial(
            static_replace.replace_static_urls,
            data_directory=getattr(descriptor, 'data_dir', None),
            course_id=course_id,
            static_asset_path=static_asset_path or descriptor.static_asset_path,
        ),
        replace_course_urls=partial(
            static_replace.replace_course_urls,
            course_id=course_id
        ),
        replace_jump_to_id_urls=partial(
            static_replace.replace_jump_to_id_urls,
            course_id=course_id,
            jump_to_id_base_url=reverse('jump_to_id', kwargs={'course_id': course_id, 'module_id': ''})
        ),
        node_path=settings.NODE_PATH,
        publish=publish,
        anonymous_student_id=anonymous_student_id,
        course_id=course_id,
        open_ended_grading_interface=open_ended_grading_interface,
        s3_interface=s3_interface,
        cache=cache,
        can_execute_unsafe_code=(lambda: can_execute_unsafe_code(course_id)),
        # TODO: When we merge the descriptor and module systems, we can stop reaching into the mixologist (cpennington)
        mixins=descriptor.runtime.mixologist._mixins,  # pylint: disable=protected-access
        wrappers=block_wrappers,
        get_real_user=user_by_anonymous_id,
        services={
            # django.utils.translation implements the gettext.Translations
            # interface (it has ugettext, ungettext, etc), so we can use it
            # directly as the runtime i18n service.
            'i18n': django.utils.translation,
        },
        get_user_role=lambda: get_user_role(user, course_id),
    )

    # pass position specified in URL to module through ModuleSystem
    system.set('position', position)
    if settings.FEATURES.get('ENABLE_PSYCHOMETRICS'):
        system.set(
            'psychometrics_handler',  # set callback for updating PsychometricsData
            make_psychometrics_data_update_handler(course_id, user, descriptor.location.url())
        )

    system.set(u'user_is_staff', has_access(user, descriptor.location, u'staff', course_id))

    # make an ErrorDescriptor -- assuming that the descriptor's system is ok
    if has_access(user, descriptor.location, 'staff', course_id):
        system.error_descriptor_class = ErrorDescriptor
    else:
        system.error_descriptor_class = NonStaffErrorDescriptor

    descriptor.xmodule_runtime = system
    descriptor.scope_ids = descriptor.scope_ids._replace(user_id=user.id)
    return descriptor
Ejemplo n.º 4
0
def get_module_system_for_user(
        user,
        field_data_cache,
        # Arguments preceding this comment have user binding, those following don't
        descriptor,
        course_id,
        track_function,
        xqueue_callback_url_prefix,
        position=None,
        wrap_xmodule_display=True,
        grade_bucket_type=None,
        static_asset_path='',
        user_location=None):
    """
    Helper function that returns a module system and student_data bound to a user and a descriptor.

    The purpose of this function is to factor out everywhere a user is implicitly bound when creating a module,
    to allow an existing module to be re-bound to a user.  Most of the user bindings happen when creating the
    closures that feed the instantiation of ModuleSystem.

    The arguments fall into two categories: those that have explicit or implicit user binding, which are user
    and field_data_cache, and those don't and are just present so that ModuleSystem can be instantiated, which
    are all the other arguments.  Ultimately, this isn't too different than how get_module_for_descriptor_internal
    was before refactoring.

    Arguments:
        see arguments for get_module()

    Returns:
        (LmsModuleSystem, KvsFieldData):  (module system, student_data) bound to, primarily, the user and descriptor
    """
    student_data = KvsFieldData(DjangoKeyValueStore(field_data_cache))

    def make_xqueue_callback(dispatch='score_update'):
        # Fully qualified callback URL for external queueing system
        relative_xqueue_callback_url = reverse(
            'xqueue_callback',
            kwargs=dict(course_id=course_id.to_deprecated_string(),
                        userid=str(user.id),
                        mod_id=descriptor.location.to_deprecated_string(),
                        dispatch=dispatch),
        )
        return xqueue_callback_url_prefix + relative_xqueue_callback_url

    # Default queuename is course-specific and is derived from the course that
    #   contains the current module.
    # TODO: Queuename should be derived from 'course_settings.json' of each course
    xqueue_default_queuename = descriptor.location.org + '-' + descriptor.location.course

    xqueue = {
        'interface': XQUEUE_INTERFACE,
        'construct_callback': make_xqueue_callback,
        'default_queuename': xqueue_default_queuename.replace(' ', '_'),
        'waittime': settings.XQUEUE_WAITTIME_BETWEEN_REQUESTS
    }

    # This is a hacky way to pass settings to the combined open ended xmodule
    # It needs an S3 interface to upload images to S3
    # It needs the open ended grading interface in order to get peer grading to be done
    # this first checks to see if the descriptor is the correct one, and only sends settings if it is

    # Get descriptor metadata fields indicating needs for various settings
    needs_open_ended_interface = getattr(descriptor,
                                         "needs_open_ended_interface", False)
    needs_s3_interface = getattr(descriptor, "needs_s3_interface", False)

    # Initialize interfaces to None
    open_ended_grading_interface = None
    s3_interface = None

    # Create interfaces if needed
    if needs_open_ended_interface:
        open_ended_grading_interface = settings.OPEN_ENDED_GRADING_INTERFACE
        open_ended_grading_interface[
            'mock_peer_grading'] = settings.MOCK_PEER_GRADING
        open_ended_grading_interface[
            'mock_staff_grading'] = settings.MOCK_STAFF_GRADING
    if needs_s3_interface:
        s3_interface = {
            'access_key':
            getattr(settings, 'AWS_ACCESS_KEY_ID', ''),
            'secret_access_key':
            getattr(settings, 'AWS_SECRET_ACCESS_KEY', ''),
            'storage_bucket_name':
            getattr(settings, 'AWS_STORAGE_BUCKET_NAME', 'openended')
        }

    def inner_get_module(descriptor):
        """
        Delegate to get_module_for_descriptor_internal() with all values except `descriptor` set.

        Because it does an access check, it may return None.
        """
        # TODO: fix this so that make_xqueue_callback uses the descriptor passed into
        # inner_get_module, not the parent's callback.  Add it as an argument....
        return get_module_for_descriptor_internal(
            user, descriptor, field_data_cache, course_id, track_function,
            make_xqueue_callback, position, wrap_xmodule_display,
            grade_bucket_type, static_asset_path, user_location)

    def handle_grade_event(block, event_type, event):
        user_id = event.get('user_id', user.id)

        # Construct the key for the module
        key = KeyValueStore.Key(scope=Scope.user_state,
                                user_id=user_id,
                                block_scope_id=descriptor.location,
                                field_name='grade')

        student_module = field_data_cache.find_or_create(key)
        # Update the grades
        student_module.grade = event.get('value')
        student_module.max_grade = event.get('max_value')
        # Save all changes to the underlying KeyValueStore
        student_module.save()

        # Bin score into range and increment stats
        score_bucket = get_score_bucket(student_module.grade,
                                        student_module.max_grade)

        tags = [
            u"org:{}".format(course_id.org), u"course:{}".format(course_id),
            u"score_bucket:{0}".format(score_bucket)
        ]

        if grade_bucket_type is not None:
            tags.append('type:%s' % grade_bucket_type)

        dog_stats_api.increment("lms.courseware.question_answered", tags=tags)

    def publish(block, event_type, event):
        """A function that allows XModules to publish events."""
        if event_type == 'grade':
            handle_grade_event(block, event_type, event)
        else:
            track_function(event_type, event)

    def rebind_noauth_module_to_user(module, real_user):
        """
        A function that allows a module to get re-bound to a real user if it was previously bound to an AnonymousUser.

        Will only work within a module bound to an AnonymousUser, e.g. one that's instantiated by the noauth_handler.

        Arguments:
            module (any xblock type):  the module to rebind
            real_user (django.contrib.auth.models.User):  the user to bind to

        Returns:
            nothing (but the side effect is that module is re-bound to real_user)
        """
        if user.is_authenticated():
            err_msg = (
                "rebind_noauth_module_to_user can only be called from a module bound to "
                "an anonymous user")
            log.error(err_msg)
            raise LmsModuleRenderError(err_msg)

        field_data_cache_real_user = FieldDataCache.cache_for_descriptor_descendents(
            course_id, real_user, module.descriptor)

        (inner_system, inner_student_data) = get_module_system_for_user(
            real_user,
            field_data_cache_real_user,  # These have implicit user bindings, rest of args considered not to
            module.descriptor,
            course_id,
            track_function,
            xqueue_callback_url_prefix,
            position,
            wrap_xmodule_display,
            grade_bucket_type,
            static_asset_path,
            user_location)
        # rebinds module to a different student.  We'll change system, student_data, and scope_ids
        module.descriptor.bind_for_student(
            inner_system,
            LmsFieldData(module.descriptor._field_data, inner_student_data)  # pylint: disable=protected-access
        )
        module.descriptor.scope_ids = (
            module.descriptor.scope_ids._replace(user_id=real_user.id)  # pylint: disable=protected-access
        )
        module.scope_ids = module.descriptor.scope_ids  # this is needed b/c NamedTuples are immutable
        # now bind the module to the new ModuleSystem instance and vice-versa
        module.runtime = inner_system
        inner_system.xmodule_instance = module

    # Build a list of wrapping functions that will be applied in order
    # to the Fragment content coming out of the xblocks that are about to be rendered.
    block_wrappers = []

    # Wrap the output display in a single div to allow for the XModule
    # javascript to be bound correctly
    if wrap_xmodule_display is True:
        block_wrappers.append(
            partial(wrap_xblock,
                    'LmsRuntime',
                    extra_data={'course-id': course_id.to_deprecated_string()},
                    usage_id_serializer=lambda usage_id: quote_slashes(
                        usage_id.to_deprecated_string())))

    # TODO (cpennington): When modules are shared between courses, the static
    # prefix is going to have to be specific to the module, not the directory
    # that the xml was loaded from

    # Rewrite urls beginning in /static to point to course-specific content
    block_wrappers.append(
        partial(replace_static_urls,
                getattr(descriptor, 'data_dir', None),
                course_id=course_id,
                static_asset_path=static_asset_path
                or descriptor.static_asset_path))

    # Allow URLs of the form '/course/' refer to the root of multicourse directory
    #   hierarchy of this course
    block_wrappers.append(partial(replace_course_urls, course_id))

    # this will rewrite intra-courseware links (/jump_to_id/<id>). This format
    # is an improvement over the /course/... format for studio authored courses,
    # because it is agnostic to course-hierarchy.
    # NOTE: module_id is empty string here. The 'module_id' will get assigned in the replacement
    # function, we just need to specify something to get the reverse() to work.
    block_wrappers.append(
        partial(
            replace_jump_to_id_urls,
            course_id,
            reverse('jump_to_id',
                    kwargs={
                        'course_id': course_id.to_deprecated_string(),
                        'module_id': ''
                    }),
        ))

    if settings.FEATURES.get('DISPLAY_DEBUG_INFO_TO_STAFF'):
        if has_access(user, 'staff', descriptor, course_id):
            has_instructor_access = has_access(user, 'instructor', descriptor,
                                               course_id)
            block_wrappers.append(
                partial(add_staff_markup, user, has_instructor_access))

    # These modules store data using the anonymous_student_id as a key.
    # To prevent loss of data, we will continue to provide old modules with
    # the per-student anonymized id (as we have in the past),
    # while giving selected modules a per-course anonymized id.
    # As we have the time to manually test more modules, we can add to the list
    # of modules that get the per-course anonymized id.
    is_pure_xblock = isinstance(
        descriptor, XBlock) and not isinstance(descriptor, XModuleDescriptor)
    module_class = getattr(descriptor, 'module_class', None)
    is_lti_module = not is_pure_xblock and issubclass(module_class, LTIModule)
    if is_pure_xblock or is_lti_module:
        anonymous_student_id = anonymous_id_for_user(user, course_id)
    else:
        anonymous_student_id = anonymous_id_for_user(user, None)

    system = LmsModuleSystem(
        track_function=track_function,
        render_template=render_to_string,
        static_url=settings.STATIC_URL,
        xqueue=xqueue,
        # TODO (cpennington): Figure out how to share info between systems
        filestore=descriptor.runtime.resources_fs,
        get_module=inner_get_module,
        user=user,
        debug=settings.DEBUG,
        hostname=settings.SITE_NAME,
        # TODO (cpennington): This should be removed when all html from
        # a module is coming through get_html and is therefore covered
        # by the replace_static_urls code below
        replace_urls=partial(
            static_replace.replace_static_urls,
            data_directory=getattr(descriptor, 'data_dir', None),
            course_id=course_id,
            static_asset_path=static_asset_path
            or descriptor.static_asset_path,
        ),
        replace_course_urls=partial(static_replace.replace_course_urls,
                                    course_key=course_id),
        replace_jump_to_id_urls=partial(
            static_replace.replace_jump_to_id_urls,
            course_id=course_id,
            jump_to_id_base_url=reverse('jump_to_id',
                                        kwargs={
                                            'course_id':
                                            course_id.to_deprecated_string(),
                                            'module_id':
                                            ''
                                        })),
        node_path=settings.NODE_PATH,
        publish=publish,
        anonymous_student_id=anonymous_student_id,
        course_id=course_id,
        open_ended_grading_interface=open_ended_grading_interface,
        s3_interface=s3_interface,
        cache=cache,
        can_execute_unsafe_code=(lambda: can_execute_unsafe_code(course_id)),
        # TODO: When we merge the descriptor and module systems, we can stop reaching into the mixologist (cpennington)
        mixins=descriptor.runtime.mixologist._mixins,  # pylint: disable=protected-access
        wrappers=block_wrappers,
        get_real_user=user_by_anonymous_id,
        services={
            'i18n': ModuleI18nService(),
        },
        get_user_role=lambda: get_user_role(user, course_id),
        descriptor_runtime=descriptor.runtime,
        rebind_noauth_module_to_user=rebind_noauth_module_to_user,
        user_location=user_location,
    )

    # pass position specified in URL to module through ModuleSystem
    if position is not None:
        try:
            position = int(position)
        except (ValueError, TypeError):
            log.exception('Non-integer %r passed as position.', position)
            position = None

    system.set('position', position)

    if settings.FEATURES.get('ENABLE_PSYCHOMETRICS'):
        system.set(
            'psychometrics_handler',  # set callback for updating PsychometricsData
            make_psychometrics_data_update_handler(course_id, user,
                                                   descriptor.location))

    system.set(u'user_is_staff',
               has_access(user, u'staff', descriptor.location, course_id))
    system.set(u'user_is_admin', has_access(user, u'staff', 'global'))

    # make an ErrorDescriptor -- assuming that the descriptor's system is ok
    if has_access(user, u'staff', descriptor.location, course_id):
        system.error_descriptor_class = ErrorDescriptor
    else:
        system.error_descriptor_class = NonStaffErrorDescriptor

    return system, student_data