old_contents: from django.utils.translation import ugettext_lazy as _
  from django.core.urlresolvers import reverse
  from django.db import models
  
  from wafer.snippets.markdown_field import MarkdownTextField
  
  from wafer.talks.models import Talk
  from wafer.pages.models import Page
  
  
  class Venue(models.Model):
      """Information about a venue for conference events"""
      order = models.IntegerField(default=1)
  
      name = models.CharField(max_length=1024)
  
      notes = MarkdownTextField(
          help_text=_("Notes or directions that will be useful to"
              " conference attendees"))
  
      def __unicode__(self):
          return u'%s' % self.name
  
      def get_absolute_url(self):
          return reverse('wafer_venue', args=(self.pk,))
  
  
  class ScheduleItem(models.Model):
  
      venue = models.ForeignKey(Venue)
  
      start_time = models.DateTimeField(null=True, blank=True)
  
      end_time = models.DateTimeField(null=True, blank=True)
  
      talk = models.ForeignKey(Talk, null=True)
      page = models.ForeignKey(Page, null=True)
      details = models.MarkdownTextField(
          null=False, blank=True,
          help_text=_("Additional details (if required)"))
  
      notes = models.TextField(
          null=False, blank=True,
          help_text=_("Notes for the conference organisers"))
  
      def get_desc(self):
          if self.details:
              if self.talk:
                  return '%s - %s' % (self.talk.title, self.details)
              elif self.page:
                  return '%s - %s' % (self.page.name, self.details)
              return self.details
          elif self.talk:
              return self.talk.title
          elif self.page:
              return self.page.name
          return ''
  
      def __unicode__(self):
          return u'%s in %s' % (self.get_desc(), self.venue)
  
new_contents: from django.utils.translation import ugettext_lazy as _
  from django.core.urlresolvers import reverse
  from django.db import models
  
  from wafer.snippets.markdown_field import MarkdownTextField
  
  from wafer.talks.models import Talk
  from wafer.pages.models import Page
  
  
  class Venue(models.Model):
      """Information about a venue for conference events"""
      order = models.IntegerField(default=1)
  
      name = models.CharField(max_length=1024)
  
      notes = MarkdownTextField(
          help_text=_("Notes or directions that will be useful to"
                      " conference attendees"))
  
      def __unicode__(self):
          return u'%s' % self.name
  
      def get_absolute_url(self):
          return reverse('wafer_venue', args=(self.pk,))
  
  
  class Slot(models.Model):
  
      # XXX: We're trading flexibility for ease of implementation here.
      #      Revisit this when we have a better idea of the actual
      #      requirements.
  
      start_time = models.DateTimeField(null=True, blank=True)
  
      end_time = models.DateTimeField(null=True, blank=True)
  
  
  class ScheduleItem(models.Model):
  
      venue = models.ForeignKey(Venue)
  
      # Items can span multiple slots (tutorials, etc).
      slot = models.ManyToMany(Slot)
  
      talk = models.ForeignKey(Talk, null=True)
      page = models.ForeignKey(Page, null=True)
      details = models.MarkdownTextField(
          null=False, blank=True,
          help_text=_("Additional details (if required)"))
  
      notes = models.TextField(
          null=False, blank=True,
          help_text=_("Notes for the conference organisers"))
  
      def get_desc(self):
          if self.details:
              if self.talk:
                  return '%s - %s' % (self.talk.title, self.details)
              elif self.page:
                  return '%s - %s' % (self.page.name, self.details)
              return self.details
          elif self.talk:
              return self.talk.title
          elif self.page:
              return self.page.name
          return ''
  
      def __unicode__(self):
          return u'%s in %s' % (self.get_desc(), self.venue)
  
subject: Change model structure