fix django views counter

Question

I am creating a blog using Django, and I want to count the views for each post. I call this function when a user reads the blog post:

def post_detail(request, post_id):
    if 'viewed_post_%s' % post_id in request.session:
        pass
    else:
        print "adding"
        add_view = Post.objects.get(id=post_id)
        add_view.views += 1
        add_view.save()
    request.session['viewed_post_%s' % post_id] = True
    return render(request, 'blog/detail.html', {'Post': Post.objects.get(id=post_id)})

The problem is that when logging out and logging in again, the post views increase again. So why does django delete the sessions when the user logs out and how can I fix this?

Answer 1

i want to edit Jahongir Rahmonov answer because it's not working for me the post_detail function:

def post_detail(request, post_id):
    post = Post.objects.get(id=post_id)
    if UserSeenPosts.objects.filter(post=post, user=request.user).exists():
        pass
    else:
        post.views += 1
        post.save()
        UserSeenPosts.objects.create(user=request.user, post=post)
    return render(request, 'blog/detail.html', {'Post': Post.objects.get(id=post_id)})

Answer 2

You cannot rely on sessions to store such permanent information because sessions are temporary.

The easiest way would be to add an additional model:

class UserSeenPosts(models.Model):
    user = models.ForeignKey(User, related_name='seen_posts')
    post = models.ForeignKey(Post)

and then do something like this:

def post_detail(request, post_id):
    post = Post.objects.get(id=post_id)

    if not request.user.seen_posts.filter(post_id=post_id).exists():
        print "adding"
        post.views += 1
        post.save()
        UserSeenPosts.objects.create(user=request.user, post=post)            

    return render(request, 'blog/detail.html', {'Post': post})

Hope it helps!