models.py

from django.db import models

# Create your models here.

class Addon(models.Model):
    name = models.CharField(max_length = 100)
    price = models.DecimalField(max_digits = 5, decimal_places = 2)

    def _unicode_(self):
        return self.name

class Product(models.Model):
    name = models.CharField(max_length = 50)
    base_price = models.DecimalField(max_digits = 7, decimal_places = 2)
    short_description = models.CharField(max_length = 100)
    long_description = models.CharField(max_length = 1000)
    thumbnail = models.ImageField(upload_to = 'thumbnails')
    product_image = models.ImageField(upload_to = 'images')
    addons = models.ManyToManyField(Addon)

    def _unicode_(self):
        return self.name

class User(models.Model):
    email_id = models.EmailField(max_length = 75)

    def _unicode_(self):
        return self.email_id


class Item(models.Model):
    delivery_address = models.CharField(max_length = 1000)
    price = models.DecimalField(max_digits = 7, decimal_places = 2)
    user = models.OneToOneField(User)
    product = models.OneToOneField(Product)

    def _unicode_(self):
        return self.product.name


class CartManager:

    def add_to_cart(request, product_id, quantity):
        product = Product.objects.get(id=product_id)
        cart = Cart(request)
        cart.add(product, product.unit_price, quantity)

    def remove_from_cart(request, product_id):
        product = Product.objects.get(id=product_id)
        cart = Cart(request)
        cart.remove(product)

    def get_cart(request):
        return render_to_response('cart.html', dict(cart=Cart(request)))