在创建新用户之前检查用户是否存在 djangorestframework

Question

到目前为止我有 - >

序列化器：

class UserSerializer(serializers.ModelSerializer):
    """Serializer to map the model instance into json format."""
    class Meta:
        """Map this serializer to a model and their fields."""
        model = User
        fields = ('id','username', 'mobile', 'password', 
                  'first_name','last_name','middle_name', 
                  'profile_pic','short_bio','friends_privacy',
                  'address_1','address_2','city',
                  'state','country','pin','verification_code',
                  'is_active','is_blocked','is_reported',
                  'date_created','date_modified')
        extra_kwargs = {'password': {'write_only': True}}
        read_only_fields = (
            'date_created', 'date_modified',
            'is_staff', 'is_superuser', 'is_active', 
            'date_joined',)
    def create(self, validated_data):
        mobile_ = validated_data['mobile']
        password_ = validated_data['password']
        username_ = validated_data['username']
        motp = self.context['request'].GET['motp']
        eotp = self.context['request'].GET['eotp']
        email_ = self.context['request'].GET['email']
        mflag = api.views.checkOTP_(mobile_,motp)
        eflag = api.views.checkOTP_(email_,eotp)
        if (mflag and eflag):
            user = User(
            username=username_,
            email =email_,
            password = make_password(password_),
            mobile = mobile_,
            )
            user.set_password(validated_data['password'])
            user.save()
            return user

看法：

class UserView2(viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer
    model = User

    def get_permissions(self):
        # allow non-authenticated user to create via POST
        return (AllowAny() if self.request.method == 'POST'
                else IsStaffOrTargetUser()),

我需要检查手机和电子邮件的 OTP 以及是否已经存在具有相同手机或电子邮件的用户。如果用户已存在，则返回带有错误的 json 响应：already exists!。如果用户是新用户并且 OTP 错误再次引发错误。如果用户是新用户且 OTP 正确，请创建一个帐户。

这里的问题是我试图添加功能来检查def create of UserSerializer. 但是序列化程序应该返回模型实例。但是，如果您看到代码，则只有当 OTP 正确且返回用户实例时，我才能创建用户。而且没有else。

那么有没有更好的方法来检查视图本身中的 OTP？

Answer 1

我不同意那里的@Anjaneyulu .. Serializer 也处理对象的创建.. 因此你有serializer.save().

但是为了为具有相同 OTP 电子邮件/电话的现有用户引发异常，您应该编写自己的def validate_mobile(self, data)和def validate_email(self, data). DRF 序列化程序将首先在类中查找这些方法，并在它们存在时运行它们。因此，您用于检查这些字段的自定义逻辑可能是：

class UserSerializer(serializers.ModelSerializer):   
    def validate_mobile(self, value):
        ModelClass = self.Meta.model
        if ModelClass.objects.filter(mobile=value).exists():
            raise serializers.ValidationError('already exists')
        return value

    def validate_email_(self, value):
        ModelClass = self.Meta.model
        if ModelClass.objects.filter(email_=value).exists():
            raise serializers.ValidationError('already exists')
        return value
    class Meta:
        model = User
        fields = (
            ...,
        )

Answer 2

这不是正确的实施方式。序列化器仅用于验证目的。您不应该create在序列化器中实现该方法，而是将其写入ViewSet. 创建对象是一个业务逻辑。它应该总是放在ViewSet. 向序列化器写入验证方法。我正在下面编写示例代码

序列化器.py

 class UserSerializer(serializers.ModelSerializer):

    def validate_mobile(self, mobile_num):
         is_already_exists = Model.objects.filter(mobile=mobile_num).exists()
         if is_already_exists:
             raise serializers.ValidationError('already exists')
         return mobile_num

    class Meta:
        model = User
        fields = (
           'id','username', 'mobile', 'password',
           'first_name','last_name','middle_name','profile_pic',
           'short_bio','friends_privacy','address_1',
           'address_2','city','state','country',
           'pin','verification_code','is_active',
               'is_blocked','is_reported',
           'date_created','date_modified'
       )
       extra_kwargs = {'password': {'write_only': True}}
       read_only_fields = (
           'date_created', 'date_modified','is_staff',
           'is_superuser', 'is_active', 'date_joined',
       )

Viewsets.py（业务逻辑）

class UserView2(viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer

    def get_permissions(self):
        # allow non-authenticated user to create via POST
        return (AllowAny() if self.request.method == 'POST'
                else IsStaffOrTargetUser()),
    def create(self, serializer):
          # your logic goes here.