from django.db import models
+from django.db.models import Count
+from django.db.models.functions import ExtractYear, ExtractMonth, Coalesce
+from django.db.models.signals import pre_save
+
+from django.dispatch import receiver
from django.contrib.auth.models import User
from django.urls import reverse
+from datetime import datetime
+
# Create your models here.
NOTE_STATUS = ((0, "Draft"),
(1, "Published"))
+class NoteQuerySet(models.QuerySet):
+ pass
+
+class NoteManager(models.Manager):
+ def all_published(self):
+ return super().get_queryset().filter(status=1).annotate(publication_date=Coalesce('published_at', 'created_at')).order_by('-publication_date')
+
+ def all(self):
+ return super().all().annotate(publication_date=Coalesce('published_at', 'created_at')).order_by('-publication_date')
+
+ def per_year(self, year):
+ return self.all_published().filter(publication_date__year=year)
+
+ def per_month(self, year, month):
+ return self.per_year(year).filter(publication_date__month=month)
+
+ def years(self):
+ return self.all_published().annotate(published_year=ExtractYear('publication_date')).values_list('published_year', flat=True).distinct().order_by('published_year')
+
+ def years_with_total(self):
+ return self.all_published().annotate(published_year=ExtractYear('publication_date')).values('published_year').annotate(total=Count('id')).order_by('published_year').values('published_year', 'total').distinct()
+
+ def months(self, year):
+ return self.per_year(year).annotate(published_month=ExtractMonth('publication_date')).values_list('published_month', flat=True).distinct().order_by('published_month')
+
+ def months_with_total(self, year):
+ return self.per_year(year).annotate(published_month=ExtractMonth('publication_date')).values('published_month').annotate(total=Count('id')).order_by('published_month').values('published_month', 'total').distinct()
+
class Note(models.Model):
title = models.CharField(max_length=250)
slug = models.SlugField(max_length=250, unique=True)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
+ published_at = models.DateTimeField(null=True, editable=False)
+
+ objects = NoteManager()
class Meta:
ordering = ['-created_at']
def is_published(self):
return self.status == 1
+
+@receiver(pre_save, sender=Note)
+def note_pre_save(sender, instance, **kwargs):
+ if instance.pk is None:
+ if instance.status == 1:
+ instance.published_at = datetime.now()
+ else:
+ old_instance = Note.objects.get(pk=instance.pk)
+
+ if old_instance.status == 0 and instance.status == 1:
+ instance.published_at = datetime.now()
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