Question

我尝试使用ListSerializer来过滤嵌套的序列化程序。除了创建新实例时的一种情况之外，这种方法完全可以正常工作。

view.py如下所示：

class NewGrade(generics.RetrieveUpdateDestroyAPIView):

    queryset = Grade.objects.all()
    serializer_class = NewGradeSerializer
    lookup_field = 'grade'
    def put(self, request, *args, **kwargs):
        try:
            flag = 1
            s1 = kwargs["schoolName"]
            g1 = kwargs["grade"]
            Grade = Grade.objects.get(school__schoolName=s1, grade=g1)
            context = {'schoolName': kwargs["schoolName"]}
            serializer = NewGradeSerializer(Grade, context = context,  data=request.data)
        except Grade.DoesNotExist:
            flag = 0
            context = {'schoolName': kwargs["schoolName"]}
            serializer = NewGradeSerializer(context = context, data=request.data)
        if serializer.is_valid():
            if flag == 0:
                serializer.create(validated_data=request.data)
            else:
                serializer.update(Grade,validated_data=request.data)
        else:
            return Response(serializer.errors)
        return Response(serializer.data, status=status.HTTP_200_OK)

嵌套的序列化程序和ListSerilazer如下所示：

class FilteredData(serializers.ListSerializer):
    def to_representation(self, data):
        school = self.context.get("schoolName")
        data = data.filter(schoolID__schoolName=school)
        return super(FilteredData, self).to_representation(data)

class StudentTemp(serializers.ModelSerializer):
    studentInfo = DisplayData(source="*")

    class Meta:
        model = Student
        list_serializer_class = FilteredData
        fields = ('studentInfo',)

class DisplayData(serializers.Serializer):
    name = serializers.CharField()
    rollNum = serializers.CharField()

class NewGradeSerializer(serializers.ModelSerializer):
    studentList = StudentTemp(many=True)

    class Meta:
        model = Grade
        fields = ("grade", "studentList")

    def create(self, validated_data):
        s1 = self.context.get("schoolName")
        sch = School.objects.get(schoolName=s1)
        student_datas = validated_data.pop('studentList')
        grade = Grade.objects.create(**validated_data)
        grade.school.set([sch]) #m2m field
        for student_data in student_datas:
            n1 = student_data["studentInfo"]["name"]
            r1 = student_data["studentInfo"]["rollNum"]
            student.objects.create(grade=grade, name=n1, rollNum=r1, schoolID = sch)
        return grade

    def update(self, instance, validated_data):
        students_data = validated_data.pop('studentList')
        for student_data in students_data:
            student_up = Student.objects.get(rollNum = student_data["student"]["rollNum"])
            student_up.name = student_data["studentInfo"]["name"]   
            student_up.save()
        return instance

我在序列化器的许多地方都使用FilteredData，并且在每种情况下都可以正常工作。但是当我尝试实现serializer.create(validated_data=request.data)时，它给了我以下错误：

'list' object has no attribute 'filter'

JSON有效负载为：

{
    "grade": "ten",
    "studentList": [
        {
            "studentInfo": {
                "name": "mark",
                "rollNum": 4
            }
        }
    ]
}

此有效负载在更新时工作得很好，但在创建时却没有。我知道为什么会收到此错误，但是我不确定如何解决该错误。它也适用于'GET'操作。也创建了新实例，但无法显示，而是显示错误。

编辑我将data打印在FilteredData中，并将所有数据打印在studentList中，而create则不应该发生。而且在任何其他情况下都不会发生，无论为什么。

使用列表序列化程序给我一个错误的“列表”对象，该对象没有属性“过滤器”

0 个答案: