notes/models.py

   1 from django.db import models
   2 from django.db.models import Count
   3 from django.db.models.functions import ExtractYear, ExtractMonth, Coalesce
   4 from django.db.models.signals import pre_save
   5
   6 from django.dispatch import receiver
   7 from django.contrib.auth.models import User
   8 from django.urls import reverse
   9
  10 from datetime import datetime
  11
  12 # Create your models here.
  13
  14 NOTE_STATUS = ((0, "Draft"),
  15                (1, "Published"))
  16
  17 class NoteQuerySet(models.QuerySet):
  18     pass
  19
  20 class NoteManager(models.Manager):
  21     def all_published(self):
  22         return super().get_queryset().filter(status=1).annotate(publication_date=Coalesce('published_at', 'created_at')).order_by('-publication_date')
  23
  24     def all(self):
  25         return super().all().annotate(publication_date=Coalesce('published_at', 'created_at')).order_by('-publication_date')
  26
  27     def per_year(self, year):
  28         return self.all_published().filter(created_at__year=year)
  29
  30     def per_month(self, year, month):
  31         return self.per_year(year).filter(created_at__month=month)
  32
  33     def years(self):
  34         return self.all_published().annotate(created_year=ExtractYear('created_at')).values_list('created_year', flat=True).distinct().order_by('created_year')
  35
  36     def years_with_total(self):
  37         return self.all_published().annotate(created_year=ExtractYear('created_at')).values('created_year').annotate(total=Count('id')).order_by('created_year').values('created_year', 'total').distinct()
  38
  39     def months(self, year):
  40         return self.per_year(year).annotate(created_month=ExtractMonth('created_at')).values_list('created_month', flat=True).distinct().order_by('created_month')
  41
  42     def months_with_total(self, year):
  43         return self.per_year(year).annotate(created_month=ExtractMonth('created_at')).values('created_month').annotate(total=Count('id')).order_by('created_month').values('created_month', 'total').distinct()
  44
  45 class Note(models.Model):
  46     title = models.CharField(max_length=250)
  47     slug = models.SlugField(max_length=250, unique=True)
  48     author = models.ForeignKey(User, on_delete=models.CASCADE, related_name='notes_posted')
  49     content = models.TextField()
  50     status = models.IntegerField(choices=NOTE_STATUS, default=0)
  51
  52     created_at = models.DateTimeField(auto_now_add=True)
  53     updated_at = models.DateTimeField(auto_now=True)
  54     published_at = models.DateTimeField(null=True, editable=False)
  55
  56     objects = NoteManager()
  57
  58     class Meta:
  59         ordering = ['-created_at']
  60
  61     def __str__(self):
  62         return self.title
  63
  64     def get_absolute_url(self):
  65         return reverse("notes:note_detail", kwargs={"note_slug": self.slug})
  66
  67     def is_draft(self):
  68         return self.status == 0
  69
  70     def is_published(self):
  71         return self.status == 1
  72
  73 @receiver(pre_save, sender=Note)
  74 def note_pre_save(sender, instance, **kwargs):
  75     if instance.pk is None:
  76         if instance.status == 1:
  77             instance.published_at = datetime.now()
  78     else:
  79         old_instance = Note.objects.get(pk=instance.pk)
  80
  81         if old_instance.status == 0 and instance.status == 1:
  82             instance.published_at = datetime.now()