Fix #389 -- Add event ical download feature (#413)

* added event ical download feature

* handle event settings and timezone

* add test cases for ical download

* fix failed test case for timezone settings

* using vobject lib to generate ical

* customised UID & add vobject dependency

src/pretix/presale/templates/pretixpresale/event/index.html

@@ -68,9 +68,20 @@
             {% endif %}
         </div>
     {% endif %}
-    {% if frontpage_text %}
+    <div>
-        {{ frontpage_text|rich_text }}
+        {% if frontpage_text %}
-    {% endif %}
+        <div class="pull-left">
+            {{ frontpage_text|rich_text }}
+        </div>
+        {% endif %}
+        <div class="pull-right">
+            <a href="{% eventurl event "presale:event.ical.download" %}" class="btn btn-link">
+                <i class="fa fa-calendar"></i> {% trans "Add to Calendar" %}
+            </a>
+        </div>
+        <div class="clearfix"></div>
+    </div>
+
     {% eventsignal event "pretix.presale.signals.front_page_top" %}
     {% if event.presale_is_running or event.settings.show_items_outside_presale_period %}
         <form method="post" data-asynctask

src/pretix/presale/urls.py

@@ -56,6 +56,9 @@ event_patterns = [
     url(r'^order/(?P<order>[^/]+)/(?P<secret>[A-Za-z0-9]+)/invoice/(?P<invoice>[0-9]+)$',
         pretix.presale.views.order.InvoiceDownload.as_view(),
         name='event.invoice.download'),
+    url(r'^ical$',
+        pretix.presale.views.event.EventIcalDownload.as_view(),
+        name='event.ical.download'),
     url(r'^auth/$', pretix.presale.views.event.EventAuth.as_view(), name='event.auth'),
     url(r'^$', pretix.presale.views.event.EventIndex.as_view(), name='event.index'),
 ]

src/pretix/presale/views/event.py

@@ -1,16 +1,22 @@
 import sys
+from datetime import datetime
 from importlib import import_module
 
+import pytz
+import vobject
 from django.conf import settings
 from django.core.exceptions import PermissionDenied
 from django.db.models import Count, Prefetch, Q
+from django.http import Http404, HttpResponse
 from django.shortcuts import redirect
 from django.utils.decorators import method_decorator
+from django.utils.functional import cached_property
 from django.utils.timezone import now
 from django.utils.translation import ugettext_lazy as _
 from django.views import View
 from django.views.decorators.csrf import csrf_exempt
 from django.views.generic import TemplateView
+from pytz import timezone
 
 from pretix.base.models import ItemVariation
 from pretix.multidomain.urlreverse import eventreverse
@@ -105,6 +111,48 @@ class EventIndex(EventViewMixin, CartMixin, TemplateView):
         return context
 
 
+class EventIcalDownload(EventViewMixin, View):
+
+    @cached_property
+    def event_timezone(self):
+        return timezone(self.request.event.settings.timezone)
+
+    def get(self, request, *args, **kwargs):
+        if not self.request.event:
+            raise Http404(_('Unknown event code or not authorized to access this event.'))
+
+        event = self.request.event
+        creation_time = datetime.now(pytz.utc)
+        cal = vobject.iCalendar()
+        cal.add('prodid').value = '-//pretix//{}//'.format(settings.PRETIX_INSTANCE_NAME)
+
+        vevent = cal.add('vevent')
+        vevent.add('summary').value = str(event.name)
+        vevent.add('dtstamp').value = creation_time
+        vevent.add('location').value = str(event.location)
+        vevent.add('organizer').value = event.organizer.name
+        vevent.add('uid').value = '{}-{}-{}'.format(
+            event.organizer.slug, event.slug, creation_time.strftime('%Y%m%d%H%M%S%f')
+        )
+
+        if event.settings.show_times:
+            vevent.add('dtstart').value = event.date_from.astimezone(self.event_timezone)
+        else:
+            vevent.add('dtstart').value = event.date_from.astimezone(self.event_timezone).date()
+
+        if event.settings.show_date_to:
+            if event.settings.show_times:
+                vevent.add('dtend').value = event.date_to.astimezone(self.event_timezone)
+            else:
+                vevent.add('dtend').value = event.date_to.astimezone(self.event_timezone).date()
+
+        resp = HttpResponse(cal.serialize(), content_type='text/calendar')
+        resp['Content-Disposition'] = 'attachment; filename="{}-{}.ics"'.format(
+            event.organizer.slug, event.slug
+        )
+        return resp
+
+
 class EventAuth(View):
     @method_decorator(csrf_exempt)
     def dispatch(self, request, *args, **kwargs):

src/requirements/production.txt

@@ -36,3 +36,4 @@ pycparser==2.13  # https://github.com/eliben/pycparser/issues/147
 # Banktransfer
 chardet>=2.3,<3
 mt-940==3.2
+vobject==0.9.*

src/setup.py

@@ -97,7 +97,8 @@ setup(
         'stripe==1.22.*',
         'chardet>=2.3,<3',
         'mt-940==3.2',
-        'django-i18nfield'
+        'django-i18nfield',
+        'vobject==0.9.*'
     ],
     extras_require={
         'dev': [

src/tests/presale/test_event.py

@@ -1,10 +1,13 @@
 import datetime
+import re
 from decimal import Decimal
 
+from django.conf import settings
 from django.core import mail
 from django.core.exceptions import ValidationError
 from django.test import TestCase
 from django.utils.timezone import now
+from pytz import timezone
 from tests.base import SoupTest
 
 from pretix.base.models import (
@@ -49,6 +52,16 @@ class EventMiddlewareTest(EventTestMixin, SoupTest):
         resp = self.client.get('/%s/%s/' % (self.orga.slug, self.event.slug))
         self.assertEqual(resp.status_code, 200)
 
+    def test_not_found_event(self):
+        resp = self.client.get('/%s/%s/ical' % ('foo', 'bar'))
+        self.assertEqual(resp.status_code, 404)
+
+    def test_mandatory_field(self):
+        self.event.date_to = self.event.date_from + datetime.timedelta(days=2)
+        self.event.save()
+        resp = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug))
+        self.assertEqual(resp.status_code, 200)
+
 
 class ItemDisplayTest(EventTestMixin, SoupTest):
     def test_not_active(self):
@@ -548,6 +561,115 @@ class TestResendLink(EventTestMixin, SoupTest):
         self.assertIn('DUMMY2', mail.outbox[0].body)
 
 
+class EventIcalDownloadTest(EventTestMixin, SoupTest):
+    def setUp(self):
+        super().setUp()
+        self.event.settings.show_date_to = True
+        self.event.settings.show_times = True
+        self.event.location = 'DUMMY ARENA'
+        self.event.date_from = datetime.datetime(2013, 12, 26, 21, 57, 58, tzinfo=datetime.timezone.utc)
+        self.event.date_to = self.event.date_from + datetime.timedelta(days=2)
+        self.event.settings.timezone = 'UTC'
+        self.event.save()
+
+    def test_response_type(self):
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug))
+        self.assertEqual(ical['Content-Type'], 'text/calendar')
+        self.assertEqual(ical['Content-Disposition'], 'attachment; filename="{}-{}.ics"'.format(
+            self.orga.slug, self.event.slug
+        ))
+
+    def test_header_footer(self):
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        self.assertTrue(ical.startswith('BEGIN:VCALENDAR'), 'missing VCALENDAR header')
+        self.assertTrue(ical.strip().endswith('END:VCALENDAR'), 'missing VCALENDAR footer')
+        self.assertIn('BEGIN:VEVENT', ical, 'missing VEVENT header')
+        self.assertIn('END:VEVENT', ical, 'missing VEVENT footer')
+
+    def test_timezone_header_footer(self):
+        self.event.settings.timezone = 'Asia/Tokyo'
+        self.event.save()
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        self.assertTrue(ical.startswith('BEGIN:VCALENDAR'), 'missing VCALENDAR header')
+        self.assertTrue(ical.strip().endswith('END:VCALENDAR'), 'missing VCALENDAR footer')
+        self.assertIn('BEGIN:VEVENT', ical, 'missing VEVENT header')
+        self.assertIn('END:VEVENT', ical, 'missing VEVENT footer')
+        self.assertIn('BEGIN:VTIMEZONE', ical, 'missing VTIMEZONE header')
+        self.assertIn('END:VTIMEZONE', ical, 'missing VTIMEZONE footer')
+
+    def test_metadata(self):
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        self.assertIn('VERSION:2.0', ical, 'incorrect version tag - 2.0')
+        self.assertIn('-//pretix//%s//' % settings.PRETIX_INSTANCE_NAME, ical, 'incorrect PRODID')
+
+    def test_event_info(self):
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        self.assertIn('SUMMARY:%s' % self.event.name, ical, 'incorrect correct summary')
+        self.assertIn('LOCATION:DUMMY ARENA', ical, 'incorrect location')
+        self.assertIn('ORGANIZER:%s' % self.event.organizer.name, ical, 'incorrect organizer')
+        self.assertTrue(re.search(r'DTSTAMP:\d{8}T\d{6}Z', ical), 'incorrect timestamp')
+        self.assertTrue(re.search(r'UID:\w*-\w*-\d{20}', ical), 'missing UID key')
+
+    def test_utc_timezone(self):
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        # according to icalendar spec, timezone must NOT be shown if it is UTC
+        self.assertIn('DTSTART:%s' % self.event.date_from.strftime('%Y%m%dT%H%M%SZ'), ical, 'incorrect start time')
+        self.assertIn('DTEND:%s' % self.event.date_to.strftime('%Y%m%dT%H%M%SZ'), ical, 'incorrect end time')
+
+    def test_include_timezone(self):
+        self.event.settings.timezone = 'Asia/Tokyo'
+        self.event.save()
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        # according to icalendar spec, timezone must be shown if it is not UTC
+        fmt = '%Y%m%dT%H%M%S'
+        self.assertIn('DTSTART;TZID=%s:%s' %
+                      (self.event.settings.timezone,
+                       self.event.date_from.astimezone(timezone(self.event.settings.timezone)).strftime(fmt)),
+                      ical, 'incorrect start time')
+        self.assertIn('DTEND;TZID=%s:%s' %
+                      (self.event.settings.timezone,
+                       self.event.date_to.astimezone(timezone(self.event.settings.timezone)).strftime(fmt)),
+                      ical, 'incorrect end time')
+        self.assertIn('TZID:%s' % self.event.settings.timezone, ical, 'missing VCALENDAR')
+
+    def test_no_time(self):
+        self.event.settings.show_times = False
+        self.event.save()
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        self.assertIn('DTSTART;VALUE=DATE:%s' % self.event.date_from.strftime('%Y%m%d'), ical, 'incorrect start date')
+        self.assertIn('DTEND;VALUE=DATE:%s' % self.event.date_to.strftime('%Y%m%d'), ical, 'incorrect end date')
+
+    def test_no_date_to(self):
+        self.event.settings.timezone = 'Asia/Tokyo'
+        self.event.settings.show_date_to = False
+        self.event.save()
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        fmt = '%Y%m%dT%H%M%S'
+        self.assertIn('DTSTART;TZID=%s:%s' %
+                      (self.event.settings.timezone,
+                       self.event.date_from.astimezone(timezone(self.event.settings.timezone)).strftime(fmt)),
+                      ical, 'incorrect start time')
+        self.assertNotIn('DTEND', ical, 'unexpected end time attribute')
+
+    def test_no_date_to_and_time(self):
+        self.event.settings.show_date_to = False
+        self.event.settings.show_times = False
+        self.event.save()
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        self.assertIn('DTSTART;VALUE=DATE:%s' % self.event.date_from.strftime('%Y%m%d'), ical, 'incorrect start date')
+        self.assertNotIn('DTEND', ical, 'unexpected end time attribute')
+
+    def test_local_date_diff_from_utc(self):
+        self.event.date_from = datetime.datetime(2013, 12, 26, 21, 57, 58, tzinfo=datetime.timezone.utc)
+        self.event.date_to = self.event.date_from + datetime.timedelta(days=2)
+        self.event.settings.timezone = 'Asia/Tokyo'
+        self.event.settings.show_times = False
+        self.event.save()
+        ical = self.client.get('/%s/%s/ical' % (self.orga.slug, self.event.slug)).content.decode()
+        self.assertIn('DTSTART;VALUE=DATE:20131227', ical, 'incorrect start date')
+        self.assertIn('DTEND;VALUE=DATE:20131229', ical, 'incorrect end date')
+
+
 class EventSlugBlacklistValidatorTest(EventTestMixin, SoupTest):
     def test_slug_validation(self):
         event = Event(