Files
edx-platform/common/lib/xmodule/xmodule/timelimit_module.py
2013-04-04 10:55:31 -04:00

149 lines
5.4 KiB
Python

import json
import logging
from lxml import etree
from time import time
from xmodule.editing_module import XMLEditingDescriptor
from xmodule.xml_module import XmlDescriptor
from xmodule.x_module import XModule
from xmodule.progress import Progress
from xmodule.exceptions import NotFoundError
from xblock.core import Float, String, Boolean, Scope
log = logging.getLogger(__name__)
class TimeLimitFields(object):
beginning_at = Float(help="The time this timer was started", scope=Scope.user_state)
ending_at = Float(help="The time this timer will end", scope=Scope.user_state)
accomodation_code = String(help="A code indicating accommodations to be given the student", scope=Scope.user_state)
time_expired_redirect_url = String(help="Url to redirect users to after the timelimit has expired", scope=Scope.settings)
duration = Float(help="The length of this timer", scope=Scope.settings)
suppress_toplevel_navigation = Boolean(help="Whether the toplevel navigation should be suppressed when viewing this module", scope=Scope.settings)
class TimeLimitModule(TimeLimitFields, XModule):
'''
Wrapper module which imposes a time constraint for the completion of its child.
'''
def __init__(self, *args, **kwargs):
XModule.__init__(self, *args, **kwargs)
self.rendered = False
# For a timed activity, we are only interested here
# in time-related accommodations, and these should be disjoint.
# (For proctored exams, it is possible to have multiple accommodations
# apply to an exam, so they require accommodating a multi-choice.)
TIME_ACCOMMODATION_CODES = (('NONE', 'No Time Accommodation'),
('ADDHALFTIME', 'Extra Time - 1 1/2 Time'),
('ADD30MIN', 'Extra Time - 30 Minutes'),
('DOUBLE', 'Extra Time - Double Time'),
('TESTING', 'Extra Time -- Large amount for testing purposes')
)
def _get_accommodated_duration(self, duration):
'''
Get duration for activity, as adjusted for accommodations.
Input and output are expressed in seconds.
'''
if self.accommodation_code is None or self.accommodation_code == 'NONE':
return duration
elif self.accommodation_code == 'ADDHALFTIME':
# TODO: determine what type to return
return int(duration * 1.5)
elif self.accommodation_code == 'ADD30MIN':
return (duration + (30 * 60))
elif self.accommodation_code == 'DOUBLE':
return (duration * 2)
elif self.accommodation_code == 'TESTING':
# when testing, set timer to run for a week at a time.
return 3600 * 24 * 7
@property
def has_begun(self):
return self.beginning_at is not None
@property
def has_ended(self):
if not self.ending_at:
return False
return self.ending_at < time()
def begin(self, duration):
'''
Sets the starting time and ending time for the activity,
based on the duration provided (in seconds).
'''
self.beginning_at = time()
modified_duration = self._get_accommodated_duration(duration)
self.ending_at = self.beginning_at + modified_duration
def get_remaining_time_in_ms(self):
return int((self.ending_at - time()) * 1000)
def get_html(self):
self.render()
return self.content
def get_progress(self):
''' Return the total progress, adding total done and total available.
(assumes that each submodule uses the same "units" for progress.)
'''
# TODO: Cache progress or children array?
children = self.get_children()
progresses = [child.get_progress() for child in children]
progress = reduce(Progress.add_counts, progresses)
return progress
def handle_ajax(self, dispatch, get):
raise NotFoundError('Unexpected dispatch type')
def render(self):
if self.rendered:
return
# assumes there is one and only one child, so it only renders the first child
children = self.get_display_items()
if children:
child = children[0]
self.content = child.get_html()
self.rendered = True
def get_icon_class(self):
children = self.get_children()
if children:
return children[0].get_icon_class()
else:
return "other"
class TimeLimitDescriptor(TimeLimitFields, XMLEditingDescriptor, XmlDescriptor):
module_class = TimeLimitModule
# For remembering when a student started, and when they should end
stores_state = True
@classmethod
def definition_from_xml(cls, xml_object, system):
children = []
for child in xml_object:
try:
children.append(system.process_xml(etree.tostring(child, encoding='unicode')).location.url())
except Exception as e:
log.exception("Unable to load child when parsing TimeLimit wrapper. Continuing...")
if system.error_tracker is not None:
system.error_tracker("ERROR: " + str(e))
continue
return {}, children
def definition_to_xml(self, resource_fs):
xml_object = etree.Element('timelimit')
for child in self.get_children():
xml_object.append(
etree.fromstring(child.export_to_xml(resource_fs)))
return xml_object