bornhack-website/news/models.py

from __future__ import unicode_literals

from django.db import models
from django.utils import encoding
from django.utils.text import slugify

from utils.models import CreatedUpdatedModel


@encoding.python_2_unicode_compatible
class NewsItem(CreatedUpdatedModel):
    class Meta:
        ordering = ['-published_at']

    title = models.CharField(max_length=100)
    content = models.TextField()
    published_at = models.DateTimeField(null=True, blank=True)
    slug = models.SlugField(max_length=255, blank=True)
    archived = models.BooleanField(default=False)

    def __str__(self):
        return self.title

    def save(self, **kwargs):
        if self.published_at:
            # if this is a new newsitem, or it doesn't have a slug, or the slug is in use on another item, create a new slug
            if (not self.pk or not self.slug or NewsItem.objects.filter(slug=self.slug).count() > 1):
                published_at_string = self.published_at.strftime('%Y-%m-%d')
                base_slug = slugify(self.title)
                slug = '{}-{}'.format(published_at_string, base_slug)
                incrementer = 1

                # We have to make sure that the slug won't clash with current slugs
                while NewsItem.objects.filter(slug=slug).exists():
                    if incrementer == 1:
                        slug = '{}-1'.format(slug)
                    else:
                        slug = '{}-{}'.format(
                            '-'.join(slug.split('-')[:-1]),
                            incrementer
                        )
                    incrementer += 1
                self.slug = slug

        super(NewsItem, self).save(**kwargs)