I am using django-rest-framework and React.js. I need a seperate function in the backend to check if CartItem.amount is lower then ProductStock.quantity, if CartItem.product equals ProductStock.id of course (this part does not work). For the same function I need to check if the pricing is the same as in Product model, but suprisingly this part of a function works. What can I do to make sure CartItem.amount will get lowered if it is higher than ProductStock.quantity?
Code below:
Product is a blueprint for the rest of the models.
ProductStock tracks the amount of different sizes of all of products.
CartItem is a model used for tracking how many products a user bought.
models.py
class Product(models.Model):
name = models.CharField(max_length=150)
price = models.IntegerField()
slug = models.SlugField(blank=True, null=True)
def __str__(self):
return self.name
def save(self, *args, **kwargs):
self.slug = slugify(self.name)
super(Product, self).save()
class ProductStock(models.Model):
product = models.ForeignKey(Product, on_delete=models.CASCADE)
size = models.CharField(max_length=6)
quantity = models.IntegerField(default=0)
def __str__(self):
return f'{self.quantity} x {self.product.name}: {self.size}'
class CartItem(models.Model):
user = models.ForeignKey(CustomUser, on_delete=models.CASCADE)
product = models.ForeignKey(ProductStock, on_delete=models.CASCADE, blank=True, null=True)
amount = models.IntegerField(default=0, blank=True, null=True)
size = models.CharField(max_length=10, blank=True, null=True)
price = models.IntegerField(blank=True, null=True)
def __str__(self):
return f'{self.user.email}, {self.product.product.name}, {self.product.size}: {self.amount}'
def save(self, *args, **kwargs):
if self.amount > self.product.quantity:
self.amount = self.product.quantity
self.size = self.product.size
self.price = self.product.product.price
super(CartItem, self).save()
views.py
def check_cart_content(request,user_id):
cart = CartItem.objects.filter(user=user_id)
for item in cart:
product_stock = ProductStock.objects.filter(product=item.product.id)
for stock in product_stock:
if item.amount > stock.quantity:
item.amount = stock.quantity
product = Product.objects.get(id=item.product.id)
if item.price != product.price:
item.price = product.price
item.save()
return JsonResponse({'success': 'Cart checked'})
>Solution :
You need to change indentation of JsonResponse cause it ends after first stock in product_stock. Also item.save() and more probably need indentation change. Revise that in clean Python.
def check_cart_content(request,user_id):
cart = CartItem.objects.filter(user=user_id)
for item in cart:
product_stock = ProductStock.objects.filter(product=item.product.id)
for stock in product_stock:
if item.amount > stock.quantity:
item.amount = stock.quantity
product = Product.objects.get(id=item.product.id)
if item.price != product.price:
item.price = product.price
item.save()
return JsonResponse({'success': 'Cart checked'})
You should think of rebuilding model tree, cause ProductStock with ForeignKey seems bad solution. It would be better to count in function of Product, something similar to:
def quantity(self):
return Product.objects.all().count()
because it works dynamically and you don’t need extra objects in database.