# -*- coding: utf-8 -*- from __future__ import division __copyright__ = "Copyright (C) 2014 Andreas Kloeckner" __license__ = """ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. """ from django.shortcuts import ( # noqa render, get_object_or_404, redirect) from django.contrib import messages from django.core.exceptions import PermissionDenied, SuspiciousOperation import datetime from course.models import ( Course, Participation, FlowAccessException, FlowVisit, participation_role, participation_status) from course.content import ( get_course_repo, get_course_desc, parse_date_spec, get_flow_desc ) def get_role_and_participation(request, course): # "wake up" lazy object # http://stackoverflow.com/questions/20534577/int-argument-must-be-a-string-or-a-number-not-simplelazyobject # noqa user = (request.user._wrapped if hasattr(request.user, '_wrapped') else request.user) if not user.is_authenticated(): return participation_role.unenrolled, None participations = list(Participation.objects.filter( user=user, course=course)) # The uniqueness constraint should have ensured that. assert len(participations) <= 1 if len(participations) == 0: return participation_role.unenrolled, None participation = participations[0] if participation.status != participation_status.active: return participation_role.unenrolled, participation else: if participation.temporary_role: return participation.temporary_role, participation else: return participation.role, participation def get_active_commit_sha(course, participation): sha = course.active_git_commit_sha if participation is not None and participation.preview_git_commit_sha: sha = participation.preview_git_commit_sha return sha.encode() def get_flow_permissions(course_desc, participation, role, flow_id, flow_desc): now = datetime.datetime.now().date() # {{{ scan for exceptions in database for exc in ( FlowAccessException.objects .filter(participation=participation, flow_id=flow_id) .order_by("expiration")): if exc.expiration is not None and exc.expiration < now: continue stipulations = exc.stipulations if not isinstance(stipulations, dict): stipulations = {} from course.content import dict_to_struct stipulations = dict_to_struct(exc.stipulations) return ( [entry.permission for entry in exc.entries.all()], stipulations ) # }}} # {{{ interpret flow rules for rule in flow_desc.access_rules: if hasattr(rule, "roles"): if role not in rule.roles: continue if hasattr(rule, "start"): start_date = parse_date_spec(course_desc, rule.start) if now < start_date: continue if hasattr(rule, "end"): end_date = parse_date_spec(course_desc, rule.end) if end_date < now: continue return rule.permissions, rule # }}} raise ValueError("Flow access rules of flow '%s' did not resolve " "to access answer for '%s'" % (flow_id, participation)) # {{{ home def home(request): courses_and_descs_and_invalid_flags = [] for course in Course.objects.all(): repo = get_course_repo(course) desc = get_course_desc(repo, course.active_git_commit_sha.encode()) role, participation = get_role_and_participation(request, course) show = True if course.hidden: if role not in [participation_role.teaching_assistant, participation_role.instructor]: show = False if not course.valid: if role != participation_role.instructor: show = False if show: courses_and_descs_and_invalid_flags.append( (course, desc, not course.valid)) def course_sort_key(entry): course, desc, invalid_flag = entry return desc.course_start courses_and_descs_and_invalid_flags.sort(key=course_sort_key) return render(request, "course/home.html", { "courses_and_descs_and_invalid_flags": courses_and_descs_and_invalid_flags }) # }}} # {{{ course page def check_course_state(course, role): if course.hidden: if role not in [participation_role.teaching_assistant, participation_role.instructor]: raise PermissionDenied("only course staff have access") elif not course.valid: if role != participation_role.instructor: raise PermissionDenied("only the instructor has access") def course_page(request, course_identifier): course = get_object_or_404(Course, identifier=course_identifier) role, participation = get_role_and_participation(request, course) check_course_state(course, role) commit_sha = get_active_commit_sha(course, participation) repo = get_course_repo(course) course_desc = get_course_desc(repo, commit_sha) from course.content import get_processed_course_chunks chunks = get_processed_course_chunks(course, course_desc, role) return render(request, "course/course-page.html", { "course": course, "course_desc": course_desc, "participation": participation, "role": role, "chunks": chunks, "participation_role": participation_role, }) # }}} class FlowContext(object): def __init__(self, request, course_identifier, flow_identifier, flow_visit=None): self.flow_visit = flow_visit self.course_identifier = course_identifier self.flow_identifier = flow_identifier self.course = get_object_or_404(Course, identifier=course_identifier) self.role, self.participation = get_role_and_participation( request, self.course) check_course_state(self.course, self.role) if self.flow_visit is not None: self.commit_sha = self.flow_visit.active_git_commit_sha.encode() else: self.commit_sha = get_active_commit_sha(self.course, self.participation) self.repo = get_course_repo(self.course) self.course_desc = get_course_desc(self.repo, self.commit_sha) self.flow_desc = get_flow_desc(self.repo, self.course, flow_identifier, self.commit_sha) self.permissions, self.stipulations = get_flow_permissions( self.course_desc, self.participation, self.role, flow_identifier, self.flow_desc) def will_receive_feedback(self): from course.models import flow_permission return ( flow_permission.see_correctness in self.permissions or flow_permission.see_answer in self.permissions) def start_flow(request, course_identifier, flow_identifier): fctx = FlowContext(request, course_identifier, flow_identifier) from course.models import flow_permission if flow_permission.view not in fctx.permissions: raise PermissionDenied() if request.method == "POST": from course.content import set_up_flow_visit_page_data if ("start_no_credit" in request.POST or "start_credit" in request.POST): visit = FlowVisit() visit.participation = fctx.participation visit.active_git_commit_sha = fctx.commit_sha.decode() visit.flow_id = flow_identifier visit.in_progress = True visit.for_credit = "start_credit" in request.POST visit.save() request.session["flow_visit_id"] = visit.id page_count = set_up_flow_visit_page_data(fctx.repo, visit, fctx.flow_desc, fctx.commit_sha) visit.page_count = page_count visit.save() return redirect("course.views.view_flow_page", course_identifier, flow_identifier, 0) else: raise SuspiciousOperation("unrecognized POST action") else: can_start_credit = flow_permission.start_credit in fctx.permissions can_start_no_credit = flow_permission.start_no_credit in fctx.permissions # FIXME take into account max attempts # FIXME resumption # FIXME view past return render(request, "course/flow-start.html", { "participation": fctx.participation, "course_desc": fctx.course_desc, "course": fctx.course, "flow_desc": fctx.flow_desc, "flow_identifier": flow_identifier, "can_start_credit": can_start_credit, "can_start_no_credit": can_start_no_credit, }) class FlowPageContext(FlowContext): """This object acts as a container for all the information that a flow page may need to render itself or respond to a POST. """ def __init__(self, request, course_identifier, flow_identifier, ordinal, flow_visit): FlowContext.__init__(self, request, course_identifier, flow_identifier, flow_visit=flow_visit) from course.models import FlowPageData page_data = self.page_data = get_object_or_404( FlowPageData, flow_visit=flow_visit, ordinal=ordinal) from course.content import get_flow_page_desc self.page_desc = get_flow_page_desc( flow_visit, self.flow_desc, page_data.group_id, page_data.page_id) from course.content import instantiate_flow_page self.page = instantiate_flow_page( "course '%s', flow '%s', page '%s/%s'" % (course_identifier, flow_identifier, page_data.group_id, page_data.page_id), self.repo, self.page_desc, self.commit_sha) from course.page import PageContext self.page_context = PageContext( course=self.course, ordinal=page_data.ordinal, page_count=flow_visit.page_count, ) # {{{ dig for previous answers from course.models import FlowPageVisit previous_answer_visits = (FlowPageVisit.objects .filter(flow_visit=flow_visit) .filter(page_data=page_data) .filter(answer__isnull=False) .order_by("-visit_time")) self.prev_answer_is_final = False self.prev_answer = None for prev_visit in previous_answer_visits: self.prev_answer = prev_visit.answer self.prev_answer_is_final = prev_visit.answer_is_final break # }}} @property def ordinal(self): return self.page_data.ordinal @property def page_count(self): return self.flow_visit.page_count @property def percentage(self): return int(100*(self.ordinal+1)/self.page_count) def create_visit(self): from course.models import FlowPageVisit page_visit = FlowPageVisit() page_visit.flow_visit = self.flow_visit page_visit.page_data = self.page_data page_visit.save() def find_current_flow_visit(request, flow_identifier): flow_visit = None flow_visit_id = request.session.get("flow_visit_id") if flow_visit_id is not None: flow_visits = list(FlowVisit.objects.filter(id=flow_visit_id)) if flow_visits and flow_visits[0].flow_id == flow_identifier: flow_visit, = flow_visits if not flow_visit.in_progress: flow_visit = False return flow_visit def render_flow_page(request, fpctx, **kwargs): args = { "course": fpctx.course, "course_desc": fpctx.course_desc, "flow_identifier": fpctx.flow_identifier, "flow_desc": fpctx.flow_desc, "ordinal": fpctx.ordinal, "page_data": fpctx.page_data, "percentage": fpctx.percentage, "flow_visit": fpctx.flow_visit, "participation": fpctx.participation, } args.update(kwargs) return render(request, "course/flow-page.html", args) def add_buttons_to_form(fpctx, form): from crispy_forms.layout import Submit form.helper.add_input( Submit("save", "Save answer", css_class="col-lg-offset-2")) if fpctx.will_receive_feedback(): form.helper.add_input(Submit("submit", "Submit final answer")) else: # Only offer 'save and move on' if student will receive no feedback if fpctx.page_data.ordinal + 1 < fpctx.flow_visit.page_count: form.helper.add_input( Submit("save_and_next", "Save answer and move on")) else: form.helper.add_input( Submit("save_and_finish", "Save answer and finish")) return form def get_pressed_button(form): buttons = ["save", "save_and_next", "save_and_finish", "submit"] for button in buttons: if button in form.data: return button raise SuspiciousOperation("could not find which button was pressed") def view_flow_page(request, course_identifier, flow_identifier, ordinal): flow_visit = find_current_flow_visit(request, flow_identifier) if flow_visit is None: messages.add_message(request, messages.WARNING, "No in-progress visit record found for this flow. " "Redirected to flow start page.") return redirect("course.views.start_flow", course_identifier, flow_identifier) fpctx = FlowPageContext(request, course_identifier, flow_identifier, ordinal, flow_visit) page_context = fpctx.page_context page_data = fpctx.page_data from course.models import FlowPageVisit, flow_permission if flow_permission.view not in fpctx.permissions: raise PermissionDenied("not allowed to view flow") if request.method == "POST": if "finish" in request.POST: return redirect("course.views.finish_flow", course_identifier, flow_identifier) else: # reject if previous answer was final if fpctx.prev_answer_is_final: raise PermissionDenied("already have final answer") form = fpctx.page.post_form(fpctx.page_context, fpctx.page_data.data, post_data=request.POST, files_data=request.POST) pressed_button = get_pressed_button(form) if form.is_valid(): # {{{ form validated, process answer messages.add_message(request, messages.INFO, "Answer saved.") page_visit = FlowPageVisit() page_visit.flow_visit = fpctx.flow_visit page_visit.page_data = fpctx.page_data page_visit.answer = fpctx.page.answer_data( fpctx.page_context, fpctx.page_data.data, form) page_visit.answer_is_final = pressed_button == "submit" page_visit.save() answer_data = page_visit.answer answer_is_final = page_visit.answer_is_final if (pressed_button == "save_and_next" and not fpctx.will_receive_feedback()): return redirect("course.views.view_flow_page", course_identifier, flow_identifier, fpctx.ordinal + 1) elif (pressed_button == "save_and_finish" and not fpctx.will_receive_feedback()): return redirect("course.views.finish_flow", course_identifier, flow_identifier) else: # continue at common flow page generation below form = fpctx.page.form_with_answer(page_context, page_data.data, page_visit.answer, page_visit.answer_is_final) # continue at common flow page generation below # }}} else: # form did not validate fpctx.create_visit() answer_data = None answer_is_final = False # continue at common flow page generation below else: fpctx.create_visit() answer_data = fpctx.prev_answer answer_is_final = fpctx.prev_answer_is_final if answer_data: form = fpctx.page.form_with_answer(page_context, page_data.data, answer_data, answer_is_final) else: form = fpctx.page.fresh_form(page_context, page_data.data) # start common flow page generation # defined at this point: form, answer_data, answer_is_final if form is not None and not answer_is_final: form = add_buttons_to_form(fpctx, form) show_correctness = None show_answer = None feedback = None if (answer_data is not None and answer_is_final): show_correctness = flow_permission.see_correctness in fpctx.permissions show_answer = flow_permission.see_answer in fpctx.permissions if show_correctness or show_answer: feedback = fpctx.page.grade(page_context, page_data.data, answer_data) title = fpctx.page.title(page_context, page_data.data) body = fpctx.page.body(page_context, page_data.data) return render_flow_page( request, fpctx, title=title, body=body, form=form, feedback=feedback, show_correctness=show_correctness, show_answer=show_answer) def finish_flow(request, course_identifier, flow_identifier): flow_visit = find_current_flow_visit(request, flow_identifier) if flow_visit is None: messages.add_message(request, messages.WARNING, "No in-progress visit record found for this flow. " "Redirected to flow start page.") return redirect("course.views.start_flow", course_identifier, flow_identifier) fctx = FlowContext(request, course_identifier, flow_identifier, flow_visit=flow_visit) request.session["flow_visit_id"] = None from django.utils.timezone import now flow_visit.completion_time = now() flow_visit.in_progress = False flow_visit.save() # FIXME confirm, ask about unanswered questions # FIXME mark answers as final # FIXME assign grade # FIXME show grade from course.content import html_body return render(request, "course/flow-completion.html", { "course": fctx.course, "course_desc": fctx.course_desc, "flow_identifier": fctx.flow_identifier, "flow_desc": fctx.flow_desc, "body": html_body(fctx.course, fctx.flow_desc.completion_text), "participation": fctx.participation, }) # }}} # vim: foldmethod=marker