Категорія: Django

from django.conf import settings
from django.db import models
from django.shortcuts import reverse

CATEGORY = (
    ('S', 'Shirt'),
    ('SP', 'Sport Wear'),
    ('OW', 'Out Wear')
)

LABEL = (
    ('N', 'NEW'),
    ('BS', 'Best Seller')
)

class Item(models.Model):
    item_name = models.CharField(max_length=100)
    price = models.FloatField()
    discount_price = models.FloatField(blank=True, null=True)
    category = models.CharField(choices=CATEGORY, max_length=2)
    label = models.CharField(max_length=2)
    description = models.TextField()

    def __str__(self):
        return self.item_name

    def get_absolute_url(self):
        return reverse("core:product", kwargs={'pk': self.pk})

    def get_add_to_cart_url(self):
        return reverse("core:add-to-cart", kwargs={"pk": self.pk})

    def get_remove_from_cart_url(self):
        return reverse("core:remove-from-cart", kwargs={"pk": self.pk})

class OrderItem(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    ordered = models.BooleanField(default=False)
    item = models.ForeignKey(Item, on_delete=models.CASCADE)
    quantity = models.IntegerField(default=1)

    def __str__(self):
        return f'{self.quantity} of {self.item.item_name}'

class Order(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    items = models.ManyToManyField(OrderItem)
    start_date = models.DateTimeField(auto_now_add=True)
    ordered_date = models.DateTimeField()
    ordered = models.BooleanField(default=False)

    def __str__(self):
        return self.user.username

from django.contrib import admin
from .models import Item, OrderItem, Order 
admin.site.register(Item)
admin.site.register(OrderItem)
admin.site.register(Order)

$ python manage.py migrate
$ python manage.py makemigrations

from django.contrib import messages                       
from django.shortcuts import render, get_object_or_404, redirect                      
from django.views.generic import ListView, DetailView                      
from django.utils import timezone                       
from .models import (                           
    Item,
    Order,
    OrderItem
)

class HomeView(ListView):
    model = Item
    template_name = 'core/home.html'

class ProductView(DetailView):
    model = Item
    template_name = 'core/product.html'

def add_to_cart(request, pk):
    item = get_object_or_404(Item, pk=pk)
    order_item, created = OrderItem.objects.get_or_create(
        item=item,
        user=request.user,
        ordered=False
    )
    order_qs = Order.objects.filter(user=request.user, ordered=False)

    if order_qs.exists():
        order = order_qs[0]

        if order.items.filter(item__pk=item.pk).exists():
            order_item.quantity += 1
            order_item.save()
            messages.info(request, "Added quantity Item")
            return redirect("core:product", pk=pk)
        else:
            order.items.add(order_item)
            messages.info(request, "Item added to your cart")
            return redirect("core:product", pk=pk)
    else:
        ordered_date = timezone.now()
        order = Order.objects.create(user=request.user, ordered_date=ordered_date)
        order.items.add(order_item)
        messages.info(request, "Item added to your cart")
        return redirect("core:product", pk=pk)

def remove_from_cart(request, pk):
    item = get_object_or_404(Item, pk=pk )
    order_qs = Order.objects.filter(
        user=request.user,
        ordered=False
    )
    if order_qs.exists():
        order = order_qs[0]
        if order.items.filter(item__pk=item.pk).exists():
            order_item = OrderItem.objects.filter(
                item=item,
                user=request.user,
                ordered=False
            )[0]
            order_item.delete()
            messages.info(request, "Item \""+order_item.item.item_name+"\" remove from your cart")
            return redirect("core:product", pk=pk)
        else:
            messages.info(request, "This Item not in your cart")
            return redirect("core:product", pk=pk)
    else:
        #add message doesnt have order
        messages.info(request, "You do not have an Order")
        return redirect("core:product", pk=pk)

from django.urls import path
from .views import (
    remove_from_cart,
    add_to_cart,
    ProductView,
    HomeView
)


app_name = 'core'

urlpatterns = [
    path('', HomeView.as_view(), name='home'),
    path('product/<int:pk>', ProductView.as_view(), name="product"),
    path('add-to-cart/<int:pk>', add_to_cart, name='add-to-cart'),
    path('remove-from-cart/<int:pk>', remove_from_cart, name='remove-from-cart'),
]

$ python manage.py runserver