【DRF-10】rest-framework之序列化(数据校验)

• 1.自定义

class TitleValidator(object):
    def __init__(self,start):
        self.start = start

    def __call__(self, value):
        if not value.startswith(self.start):
            message = '标题必须以 %s 为开头。' % self.start
            raise serializers.ValidationError(message)

    def set_context(self, serializer_field):
        """
        This hook is called by the serializer instance,
        prior to the validation call being made.
        """
        # 执行验证之前调用,serializer_fields是当前字段对象
        pass

class UserGroupSerializer(serializers.Serializer):
    title = serializers.CharField(error_messages={'required':'组名不能为空'},validators=[TitleValidator('test'),])

class UserGroupView(APIView):
    def post(self,request,*args,**kwargs):
        ser = UserGroupSerializer(data=request.data)
        if ser.is_valid():
            print(ser.validated_data['title'])
            return HttpResponse("提交成功")
        else:
            print(ser.errors)   # {'title': [ErrorDetail(string='标题必须以 test 为开头。', code='invalid')]}
            return HttpResponse(ser.errors)

• 2.基于ModelSerializer

class TitleValidator(object):
    def __init__(self,start):
        self.start = start

    def __call__(self, value):
        if not value.startswith(self.start):
            message = '标题必须以 %s 为开头。' % self.start
            raise serializers.ValidationError(message)

    def set_context(self, serializer_field):
        """
        This hook is called by the serializer instance,
        prior to the validation call being made.
        """
        # 执行验证之前调用,serializer_fields是当前字段对象
        pass

class UserGroupSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.UserGroup
        fields = '__all__'
        depth = 1
        extra_kwargs = {'title': {'validators': [TitleValidator('test'), ]}}


class UserGroupView(APIView):

    def post(self,request,*args,**kwargs):
        ser = UserGroupSerializer(data=request.data)
        if ser.is_valid():
            print(ser.validated_data['title'])
            return HttpResponse("提交成功")
        else:
            print(ser.errors)   # {'title': [ErrorDetail(string='标题必须以 test 为开头。', code='invalid')]}
            return HttpResponse(ser.errors)

• 3.钩子函数

class UserGroupSerializer(serializers.Serializer):
    title = serializers.CharField()
    # 钩子函数，validate + “_” + 字段名称
    def validate_title(self,value):
        if not value.startswith("test"):
            message = '标题必须以 test 为开头'
            raise serializers.ValidationError(message)

class UserGroupView(APIView):

    def post(self,request,*args,**kwargs):
        ser = UserGroupSerializer(data=request.data)
        if ser.is_valid():
            print(ser.validated_data['title'])
            return HttpResponse("提交成功")
        else:
            print(ser.errors)   # {'title': [ErrorDetail(string='标题必须以 test 为开头。', code='invalid')]}
            return HttpResponse(ser.errors)