How to divide Json strings.? - django

Question

I have 4 models Category, Vendor, Location, Product. Vendor fall under the Category model (vendor is a foreign key to category). The remaining models are under Vendor (Location, Product)
ProductSerializer and LocationSerializer are nested to VendorSerializer, and VendorSerializer is nested to CategorySerializer.
class ProductSerializer(WritableNestedModelSerializer):
class Meta:
model = Product
fields = ['id', 'item_name', 'price']
read_only_fields = ['id']
class LocationSerializer(WritableNestedModelSerializer):
class Meta:
model = Location
fields = ['place']
class VendorSerializer(WritableNestedModelSerializer):
vendor_location = LocationSerializer()
product = ProductSerializer(many=True)
class Meta:
model = Vendor
fields = ['vendor_name','vendor_location','product']
read_only_fields = ['id']
class CategorySerializer(WritableNestedModelSerializer):
vendor = VendorSerializer(many=True)
class Meta:
model = Category
fields = ['id', 'category_name', 'tittle', 'vendor']
read_only_fields = ['id']
# View
class ProductView(APIView):
permission_classes = [IsAuthenticated]
def get(self, request, format=None, *args, **kwargs):
products = Category.objects.all()
serializer = CategorySerializer(products, many=True, context={'request': request})
return Response({'response': 'ok', 'result': serializer.data})
# Output
{
"response": "ok",
"result": [
{
"id": 1,
"category_name": "Cake",
"tittle": "test title",
"vendor": [
{
"vendor_name": "Test_Name",
"vendor_location": {
"place": "Test_Place"
},
"product": [
{
"id": 1,
"item_name": "test_1",
"price": 3200,
},
{
"id": 2,
"item_name": "test_2",
"price": 2010,
}
]
}
]
}
]
}
# Expected output
{
"response": "ok",
"result": [
{
"id": 1,
"category_name": "Cake",
"tittle": "test title",
"vendor": [
{
"vendor_name": "Test_Name",
"vendor_location": {
"place": "Test_Place"
},
"product": [
{
"id": 1,
"item_name": "test_1",
"price": 3200,
}
]
}
]
},
{
"id": 1,
"category_name": "Cake",
"tittle": "test title",
"vendor": [
{
"vendor_name": "Test_Name",
"vendor_location": {
"place": "Test_Place"
},
"product": [
{
"id": 2,
"item_name": "test_2",
"price": 2010,
}
]
}
]
}
]
}
In my output, two products are listed. There may be more than two. I only need one product under the product. All products must be printed in the same structure as I mentioned in expected output. How do I do this? Is it possible? Can someone help me do this?

Answer 1

You can modify this line:
# old:
products = Category.objects.all() # definately these are not products
# new:
products = Product.objects.values_list('id', flat=True) # get all products ids
categories = Category.objects.filter(vendor__product__in=products)
And send categories to CategorySerializer, thought this is still not what you want, as every duplicated category will hold information about all products (not only one).
Where I would go from this point? I'd create method get_product in VendorSerializer and somehow save information what Category/Vendor are we in right now and if we have already added a Product for this Category - I'd skip adding next.
PS. I still don't get why you need this format though.