Django - How to make an upvote button? - django

Question

Currently logged in users can upvote x amount of times.
The idea of fixing it is to create a new model called Vote. And it will have foreignkeys for user and product. When someone goes to upvote, you check and see:
is there vote object with this user id and product id, and if there is, you don't allow him to upvote again; and if it is not, then you can go ahead and create that, and just increase total_votes on one.
But actually, i ran into it and cant figure it out and solve.
So, there is my models.py
from django.db import models
from django.contrib.auth.models import User
class Product(models.Model):
title = models.CharField(max_length=255)
pub_date = models.DateTimeField()
body = models.TextField()
url = models.TextField()
image = models.ImageField(upload_to='images/')
icon = models.ImageField(upload_to='images/')
votes_total = models.IntegerField(default=1)
hunter = models.ForeignKey(User, on_delete=models.CASCADE)
def __str__(self):
return self.title
def summary(self):
return self.body[:100]
def pub_date_pretty(self):
return self.pub_date.strftime('%b %e %Y')
class Vote(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
voteproduct = models.ForeignKey(Product, on_delete=models.CASCADE)
And my views.py
from django.shortcuts import render, redirect, get_object_or_404
from django.contrib.auth.decorators import login_required
from .models import Product, Vote
from django.utils import timezone
#login_required(login_url="/accounts/signup")
def upvote(request, product_id):
if request.method == 'POST':
product = get_object_or_404(Product, pk=product_id)
product.votes_total += 1
product.save()
return redirect('/products/' + str(product.id))
Updates:
class Vote(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
product = models.ForeignKey(Product, on_delete=models.CASCADE)
class Meta:
unique_together(('user', 'product'),)
views.py
if request.method == 'POST':
product = get_object_or_404(Product, pk=product_id)
try:
Vote.objects.create(user=request.user, product=product)
product.votes_total += 1
product.save()
except:
product.save()
return redirect('/products/' + str(product.id))
Also, how should i change my .html file? I really cant understand what is going on. Looking forward to hear from u.
{% for product in products.all %}
<div class="row pt-3">
<div class="col-2" onclick="window.location='{% url 'detail' product.id
%}';" style="cursor: pointer;">
<img src="{{ product.icon.url }}" class="img-fluid" />
</div>
<div class="col-7" onclick="window.location='{% url 'detail' product.id
%}';" style="cursor: pointer;">
<h1>{{ product.title }}</h1>
<p>{{ product.summary }}</p>
</div>
<div class="col-3">
<a href="javascript:{document.getElementById('{% url 'upvote'
product.id %}').submit()}"><button class="btn btn-primary btn-lg btn-
block" name="btn1" value="upvote"><span class="oi oi-caret-top">
</span> Upvote {{ product.votes_total }}</button></a>
</div>
</div>
<form id="get_redirect_url{{ product.id }}" action="{% url 'upvote'
object.id %}" method="POST">
{% csrf_token %}
<input type="hidden" />
</form>

Answer 1

well if i were you i would do it like that :
#step 1 change votes_total from integerfield to manytomany field
##models
class Product(models.Model):
#other fields goes here
votes_total = models.ManyToManyField(User, related_name="votes" ,)
#step 2 ; go to your views.py and copy paste the following :
from django.views.generic import RedirectView
class ProductVoteToggle(RedirectView):
def get_redirect_url(self, *args ,**kwargs):
obj = get_object_or_404(Product, pk=self.kwargs['pk'])
url_ = obj.get_absolute_url()
user = self.request.user
if user.is_authenticated():
if user in obj.votes_total.all():
# you could remove the user if double upvote or display a message or what ever you want here
obj.votes_total.remove(user)
else:
obj.votes_total.add(user)
return url_
#step 3 : go to urls.py and paste add the following :
urlpatterns = [
#other urls here
path('vote/<int:pk>',ProductVoteToggle.as_view() , name="upvote"),
]
#in your template remove that form and paste the following code :
<a href="{% url 'upvote' product.id %}>Click to vote<a/>
when you are done it should work if it didn't past the error here and i'll let you know what you are doing wrong

Answer 2

Your code doesn't use Vote at all. In upvote(), first try to create a Vote for the user and product:
try:
Vote.objects.create(user=request.user, product=product)
# consider using the name product instead of voteproduct
If it succeeds, increment the counter. If it fails, notify the user that they have voted already.
Obviously, you need a unique constraint in Vote:
class Meta:
unique_together = ('user', 'product')