from django.db import models from timezones.fields import TimeZoneField CONFERENCE_CACHE = {} class Conference(models.Model): """ the full conference for a specific year, e.g. US PyCon 2012. """ title = models.CharField(max_length=100) # when the conference runs start_date = models.DateField(null=True, blank=True) end_date = models.DateField(null=True, blank=True) # timezone the conference is in timezone = TimeZoneField(blank=True) def __unicode__(self): return self.title def save(self, *args, **kwargs): super(Conference, self).save(*args, **kwargs) if self.id in CONFERENCE_CACHE: del CONFERENCE_CACHE[self.id] def delete(self): pk = self.pk super(Conference, self).delete() try: del CONFERENCE_CACHE[pk] except KeyError: pass class Section(models.Model): """ a section of the conference such as "Tutorials", "Workshops", "Talks", "Expo", "Sprints", that may have its own review and scheduling process. """ conference = models.ForeignKey(Conference) name = models.CharField(max_length=100) # when the section runs start_date = models.DateField(null=True, blank=True) end_date = models.DateField(null=True, blank=True) def __unicode__(self): return self.name def current_conference(): from django.conf import settings try: conf_id = settings.CONFERENCE_ID except AttributeError: from django.core.exceptions import ImproperlyConfigured raise ImproperlyConfigured("You must set the CONFERENCE_ID setting.") try: current_conf = CONFERENCE_CACHE[conf_id] except KeyError: current_conf = Conference.objects.get(pk=conf_id) CONFERENCE_CACHE[conf_id] = current_conf return current_conf