cosmetics_shop/apps/customer/order/serializers.py

# coding=utf-8

import datetime

from rest_framework import serializers

from utils.exceptions import CustomError

from apps.order.models import ShoppingCart


class ShoppingCartSerializer(serializers.ModelSerializer):

    class Meta:
        model = ShoppingCart
        fields = '__all__'

    def validate(self, attrs):
        if 'quantity' in attrs:
            try:
                quantity = int(attrs['quantity'])
            except:
                raise CustomError(u'商品数量错误，请修改！')
            if quantity <= 0:
                raise CustomError(u'商品数量错误，请修改！')
        return attrs

    def create(self, validated_data):
        validated_data['customer'] = self.context['request'].customer
        if int(validated_data['quantity']) <= 0:
            raise CustomError('商品数量错误，请修改！')
        instance = ShoppingCart.objects.filter(commodity_details=validated_data['commodity_details'], customer=validated_data['customer']).first()
        if instance:
            instance.quantity += validated_data['quantity']
            instance.save()
        else:
            instance = super(ShoppingCartSerializer, self).create(validated_data)
        return instance