Modelo para Noticia

from django.db import models
from django.template.defaultfilters import slugify
from django.core.urlresolvers import reverse

from authors.models import Author
from subtopic.models import Subtopic
from topic.models import Topic
from keyWords.models import KeyWord

#Global Vars


# Create your models here.

class New(models.Model):
    title = models.CharField(verbose_name='Título', max_length=255, unique=True)
    topic = models.ForeignKey(Topic, verbose_name='Tema', related_name='news', )
    subtopic = models.ForeignKey(Subtopic, verbose_name='Subtema', related_name='news') #Filtramos por Opinion para sacar todas las columnas
    author = models.ForeignKey(Author, verbose_name='Autor', related_name='news')
    keyword = models.ManyToManyField(KeyWord, blank=True, verbose_name='Palabras Clave', related_name='news')
    dateTime = models.DateTimeField(auto_now_add=True, verbose_name='Fecha y Hora')
    place = models.CharField(max_length=255, verbose_name='Lugar')
    content = models.TextField(verbose_name='Contenido')
    source = models.URLField(verbose_name='Fuente', blank=True)
    slug =  models.SlugField(verbose_name='Slug', max_length=100, unique=True)
    is_published = models.BooleanField(verbose_name='Publicada', default=False,) #Nueva, para verificar si se publica o no
    times_viewed = models.PositiveIntegerField(default=0, editable=False, verbose_name='Veces Vista' )

    class Meta:
        ordering=['-dateTime']
        verbose_name_plural='Noticias'

    #@models.permalink
    #def get_absolute_url(self):
    #    return ('news.views.New_view', None, {'year': self.dateTime.year,
    #    'month': self.dateTime.strftime('%m'),
    #    'day': self.dateTime.strftime('%d'),
    #    'slug': self.slug})

    def first_image(self):
        return self.images.first() # siendo images el related_name en Image

    def first_video(self):
        return self.video.first()

    def get_absolute_url(self):
        return reverse ('NewsDefaultView', args = [str(self.dateTime.strftime("%Y")), str(self.dateTime.strftime("%b")), str(self.dateTime.strftime("%d")), str(self.slug)])

    def get_all_keys(self):
        return '%s, ' % self.keyword

    #def is_published(self): devuelve si la noticia ha sido pulicada para que salga en la lista de noticias

    def __str__(self):
        return self.title

    def save(self):  #Definir metodo para guardar, validar y otros metodos del Slug
        super(New, self).save() #Solo con este me funciona correctamente
        if not self.id:
            self.slug = slugify(self.title)
        super(New, self).save()

from django.core.cache import cache
from django.db.models.signals import post_save
from django.dispatch import receiver

from django.contrib.sessions.models import Session
@receiver(post_save)
def clear_cache(sender, **kwargs):
    if sender != Session:
        cache.clear()