Django REST Framework序列化

一、自定义序列化

1、url

urlpatterns = [
    path('books/', books, name='books')
]

2、model

class Book(models.Model):
    b_name = models.CharField(max_length=20)
    b_price = models.FloatField(default=1)

    def to_dict(self):
        return {
            'b_name': self.b_name,
            'b_price': self.b_price
        }

3、视图

@csrf_exempt
def books(request):
    if request.method == 'GET':
        book_list = Book.objects.all()
        book_list_json = []
        for book in book_list:
            book_list_json.append(book.to_dict())
            print(book_list_json)

        data = {
            'status': 200,
            'msg': 'ok',
            'data': book_list_json
        }

        return JsonResponse(data=data)

    elif request.method == 'POST':
        b_name = request.POST.get('b_name')
        b_price = request.POST.get('b_price')

        book = Book()
        book.b_name = b_name
        book.b_price = b_price
        book.save()

        data = {
            'status': 201,
            'msg': 'ok',
            'data': book.to_dict()
        }

        return JsonResponse(data=data, status=201)

 二、Django REST Framework序列化

1、小试牛刀

（1）、model

class Person(models.Model):
    p_name = models.CharField(max_length=32)
    p_age = models.IntegerField(default=1)
    p_sex = models.BooleanField(default=False)

(2)、序列化类

创建一个serializers.py文件

from rest_framework import serializers

from Api.models import Person


class PersonSerializer(serializers.Serializer):

    id = serializers.IntegerField(read_only=True)
    p_name = serializers.CharField(max_length=32)
    p_age = serializers.IntegerField(default=1)
    p_sex = serializers.BooleanField(default=False)

    def create(self, validated_data):
        return Person.objects.create(**validated_data)

    def update(self, instance, validated_data):

        instance.p_name = validated_data.get('p_name', instance.p_name)
        instance.p_age = validated_data.get('p_age', instance.p_age)
        instance.p_sex = validated_data.get('p_sex', instance.p_sex)
        instance.save()

        return instance

序列化器类的第一部分定义了序列化/反序列化的字段。create()和update()方法定义了在调用serializer.save()时如何创建和修改完整的实例。

序列化器类与Django Form类非常相似，并在各种字段中包含类似的验证标志，例如required，max_length和default。

（3）、视图

class PersonView(View):

    def get(self, request):

        persons = Person.objects.all()

        person_serializer = PersonSerializer(persons, many=True)

        return JsonResponse(person_serializer.data, safe=False)

    def post(self, request):

        p_name = request.POST.get("p_name")
        p_age = request.POST.get("p_age")

        person = Person()

        person.p_name = p_name

        person.p_age = p_age

        person.save()

        person_serializer = PersonSerializer(person)

        return JsonResponse(person_serializer.data)

 

 2、使用ModelSerializers

我们的PersonSerializer类中重复了很多包含在Person模型类（model）中的信息。如果能保证我们的代码整洁，那就更好了.

就像Django提供了Form类和ModelForm类一样，REST framework包括Serializer类和ModelSerializer类。

注意：

　　  下面的request已经不是django中的renquest,而是rest framework中的。

　　  在post请求中可以直接使用request.data获取到所有数据进行序列化。

request.data  # 处理任意数据  适用于'POST'，'PUT'和'PATCH'方法

(1)、序列化

class PersonSerializer(serializers.ModelSerializer):
    class Meta:
        model = Person
        #fields = ('id', 'p_name', 'p_age', 'p_sex')
　　　　　fields = "__all__"

(2)、视图

class PersonView(APIView):
    def get(self, request):
        persons = Person.objects.all()
        person_serializer = PersonSerializer(persons, many=True)   # 使用序列化类进行序列化
        return Response(person_serializer.data)

    def post(self, request):
        # p_name = request.POST.get('p_name')
        # p_age = request.POST.get('p_age')
        # person = Person()
        # person.p_name = p_name
        # person.p_age = p_age
        # person.save()
        person_serializer = PersonSerializer(data=request.data)
        if person_serializer.is_valid():  # 验证数据合法性
            person_serializer.save()
            return Response(person_serializer.data)
        return Response(data={'msg': 'error'}, status=status.HTTP_400_BAD_REQUEST)

3、序列化常规Django视图函数

@csrf_exempt
@api_view(http_method_names=['GET', 'POST'])
def persons(request):
    print(type(request))
    if request.method == 'GET':
        person = Person.objects.all()
        person_serializer = PersonSerializer(person, many=True)
        print(person_serializer)
        return Response(person_serializer.data)


    elif request.method == 'POST':
        person_serializer = PersonSerializer(data=request.data)
        if person_serializer.is_valid():
            person_serializer.save()
            return Response(person_serializer.data)
        return Response(data={'msg': 'error'}, status=status.HTTP_400_BAD_REQUEST)