old_contents: from django.core.urlresolvers import reverse
  from django.db import models
  
  
  # Model Field Reference
  # https://docs.djangoproject.com/en/1.8/ref/models/fields/
  
  
  class Tag(models.Model):
      name = models.CharField(
          max_length=31, unique=True)
      slug = models.SlugField(
          max_length=31,
          unique=True,
          help_text='A label for URL config.')
  
      class Meta:
          ordering = ['name']
  
      def __str__(self):
          return self.name.title()
  
      def get_absolute_url(self):
          return reverse('organizer_tag_detail',
                         kwargs={'slug': self.slug})
  
  
  class Startup(models.Model):
      name = models.CharField(
          max_length=31, db_index=True)
      slug = models.SlugField(
          max_length=31,
          unique=True,
          help_text='A label for URL config.')
      description = models.TextField()
      founded_date = models.DateField(
          'date founded')
      contact = models.EmailField()
      website = models.URLField(max_length=255)
      tags = models.ManyToManyField(Tag)
  
      class Meta:
          ordering = ['name']
          get_latest_by = 'founded_date'
  
      def __str__(self):
          return self.name
  
  
  class NewsLink(models.Model):
      title = models.CharField(max_length=63)
      pub_date = models.DateField('date published')
      link = models.URLField(max_length=255)
      startup = models.ForeignKey(Startup)
  
      class Meta:
          verbose_name = 'news article'
          ordering = ['-pub_date']
          get_latest_by = 'pub_date'
  
      def __str__(self):
          return "{}: {}".format(
              self.startup, self.title)
  
new_contents: from django.core.urlresolvers import reverse
  from django.db import models
  
  
  # Model Field Reference
  # https://docs.djangoproject.com/en/1.8/ref/models/fields/
  
  
  class Tag(models.Model):
      name = models.CharField(
          max_length=31, unique=True)
      slug = models.SlugField(
          max_length=31,
          unique=True,
          help_text='A label for URL config.')
  
      class Meta:
          ordering = ['name']
  
      def __str__(self):
          return self.name.title()
  
      def get_absolute_url(self):
          return reverse('organizer_tag_detail',
                         args=(self.slug,))
  
  
  class Startup(models.Model):
      name = models.CharField(
          max_length=31, db_index=True)
      slug = models.SlugField(
          max_length=31,
          unique=True,
          help_text='A label for URL config.')
      description = models.TextField()
      founded_date = models.DateField(
          'date founded')
      contact = models.EmailField()
      website = models.URLField(max_length=255)
      tags = models.ManyToManyField(Tag)
  
      class Meta:
          ordering = ['name']
          get_latest_by = 'founded_date'
  
      def __str__(self):
          return self.name
  
  
  class NewsLink(models.Model):
      title = models.CharField(max_length=63)
      pub_date = models.DateField('date published')
      link = models.URLField(max_length=255)
      startup = models.ForeignKey(Startup)
  
      class Meta:
          verbose_name = 'news article'
          ordering = ['-pub_date']
          get_latest_by = 'pub_date'
  
      def __str__(self):
          return "{}: {}".format(
              self.startup, self.title)
  
subject: Use args in get_absolute_url of Tag.