django multiple if else refactor

Question

I have a function with multiple if else statements that I'm trying to simplify in Django

Is there a pattern or maybe a better modeling approach that I could use here?

The idea behind is to have a thumbs up, thumbs down behavior for each blog post

views.py

@login_required
def blog_post_vote(request, slug):
 post = get_object_or_404(BlogPost, slug=slug)
 if request.method == "POST":
 vote = request.POST['vote']
 has_user_voted = BlogPostUserVote.objects.filter(blog_post=post, user=request.user).count()
 if has_user_voted == 0:
 if vote == "yes":
 user_vote_yes = BlogPostUserVote(blog_post=post, user=request.user, vote_yes=1)
 user_vote_yes.save()
 if vote == "no":
 user_vote_no = BlogPostUserVote(blog_post=post, user=request.user, vote_no=1)
 user_vote_no.save()
 else:
 has_user_voted_yes = BlogPostUserVote.objects.filter(blog_post=post, user=request.user, vote_yes=1).count()
 has_user_voted_no = BlogPostUserVote.objects.filter(blog_post=post, user=request.user, vote_no=1).count()
 if vote == "yes" and has_user_voted_yes == 0:
 user_vote_yes = BlogPostUserVote(blog_post=post, user=request.user, vote_yes=1)
 user_vote_yes.save()
 BlogPostUserVote.objects.filter(blog_post=post, user=request.user, vote_no=1).delete()
 if vote == "no" and has_user_voted_no == 0:
 user_vote_no = BlogPostUserVote(blog_post=post, user=request.user, vote_no=1)
 user_vote_no.save()
 BlogPostUserVote.objects.filter(blog_post=post, user=request.user, vote_yes=1).delete()
 return redirect(request.META['HTTP_REFERER'])

models.py

class BlogPost(models.Model):
 user = models.ForeignKey(User, on_delete=models.CASCADE)
 image = models.ImageField(upload_to='images/', blank=True, null=True)
 title = models.CharField(max_length=500)
 # Slug = Short URL Label
 slug = models.SlugField(unique=True)
 content = models.TextField(null=True, blank=True)
 publish_date = models.DateTimeField(
 auto_now=False, auto_now_add=False, null=True, blank=True)
 timestamp = models.DateTimeField(auto_now=True)
 updated = models.DateTimeField(auto_now=True)
 @property
 def thumbs_up(self):
 return BlogPostUserVote.objects.filter(blog_post=self).aggregate(Sum("vote_yes"))['vote_yes__sum']
 @property
 def thumbs_down(self):
 return BlogPostUserVote.objects.filter(blog_post=self).aggregate(Sum("vote_no"))['vote_no__sum']
 # This line is very important as it maps the objects to the default manager
 objects = BlogPostManager()
 # Ordering Newest to Oldest
 class Meta:
 ordering = ['-publish_date', '-updated', '-timestamp']
 def get_absolute_url(self):
 return f"/blog/{self.slug}"
class BlogPostUserVote(models.Model):
 blog_post = models.ForeignKey(BlogPost, on_delete=models.CASCADE)
 user = models.ForeignKey(User, on_delete=models.CASCADE)
 vote_yes = models.SmallIntegerField(null=True, blank=True)
 vote_no = models.SmallIntegerField(null=True, blank=True)

• Teepeemm: What are has_user_voted and friends? Reading the variable name, I would think a boolean True/False. But you keep checking if ==0 instead.
• Laycoonz: Hi, it is a query against the BlogPostUserVote table and if it finds any record with the given filter will return a number greather than 0. Not exactly a boolean though
• BCdotWEB: Your title is too generic. Please read codereview.stackexchange.com/help/how-to-ask .

Answer 1

Well finally I ended up with the following, I changed some names to make it more explanatory and the function to respond to an ajax request. However the logic is pretty much the same:

@login_required
@csrf_exempt
def blog_post_reaction(request, slug):
 post = get_object_or_404(BlogPost, slug=slug)
 if request.is_ajax and request.method == "POST":
 reaction = json.loads(request.body)['vote']
 BlogPostUserReaction.objects.filter(blog_post=post, user=request.user).delete()
 new_user_reaction = BlogPostUserReaction(blog_post=post, user=request.user)
 if reaction == "upvote":
 new_user_reaction.upvote = 1
 if reaction == "downvote":
 new_user_reaction.downvote = 1
 if any((new_user_reaction.upvote, new_user_reaction.downvote)):
 new_user_reaction.save()
 return JsonResponse({'slug': slug, 'upvotes': post.upvote, 'downvotes': post.downvote})