$Django Rest Framework-序列化组件

1 序列化组件

 e=serializers.SerializerMethodField()

  # 方法名:叫get_字段名, 参数,返回字典
  　　def get_e(self,obj): #obj为book对象

from app01 import models
from rest_framework import serializers
from rest_framework.serializers import  Serializer,ModelSerializer
from django.http import JsonResponse

class auth(Serializer):
    name=serializers.CharField()
    age=serializers.CharField()
#方式1
class ser(Serializer): #*****如果不指定source,字段必须对应起来,如果指定了source,字段可以任意命名
    a=serializers.CharField(source='name') #source 可以指定字段,也可也指定方法
    b=serializers.CharField(source='authors')
    c=serializers.CharField(source='publish.name')
    d=serializers.CharField(source='publish.test')
    e=serializers.SerializerMethodField()
    # 方法名:叫get_字段名,要传参数,参数是:当前book对象
    def get_e(self,obj): #obj为book对象
        # for循环
        # li=[{'name':i.name,'age':i.age} for i in obj.authors.all()]
        # return li
        #序列化
        auths=obj.authors.all()
        li=auth(auths,many=True)
        return li.data
#方式2
class ser1(ModelSerializer):
    class Meta:
        model=models.Book
        fields='__all__'
        # fields=['name','price']
        # exclude=['authors']
        depth=10 #深度为1 当前模型字段 为2跨1个表的字段
#cbv视图      
class show(APIView):
    def get(self,request):
        #drf
        books=models.Book.objects.all()
        bb=ser1(instance=books,many=True)  #queryset对象/也可以是多单个对象|||many指定单个多个
        print(bb.data) #json格式dic
        return JsonResponse(bb.data,safe=False)
        #django自带的
        # from django.core import serializers
        # books=models.Book.objects.all()
        # ret=serializers.serialize('json',books)
        # print(ret,type(ret)) #json格式str
        # dic = {'data': ret}
        # return HttpResponse(ret)

 2 序列化组件

①前台url请求数据:

HyperlinkedIdentityField 返回一个数据带链接 写在继承Serializer的类中(很少用)

*3个参数以及scontext={'request':request}  #拼了一条路由

class Ser_link(Serializer):
    name=serializers.CharField(max_length=32,error_messages={'max_length':'最长32位'})
    #get请求时Ser_link(books,many=True,context={'request':request}) 域名
    #参1:路由别名 参2:字段 参3:有名分组名
    publish = serializers.HyperlinkedIdentityField (view_name='aaa', lookup_field='publish_id', lookup_url_kwarg='id')
class Books(APIView):
    def get(self,request):
        books=models.Book.objects.all()
        ser=Ser_link(books,many=True,context={'request':request})
        return JsonResponse(ser.data,safe=False)

url(r'^books/$', views.Books.as_view()),

url(r'^publish/(?P<id>d+)$', views.Publish.as_view(),name='aaa')
#http://127.0.0.1/publish/1

②前台传数据到后台:

0直接调save()保存更新的话,(必须继承ModelSerializer）

1.数据校验(与form组件类似有error_messages,局部钩子等) 2.数据保存/更新(传instance和不传instance的区别# 不传instance,调save(),往数据库新增数据# 传instance,调save(),修改数据,)

class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Book
        fields = '__all__'

    name = serializers.CharField(min_length=2, error_messages={'required': '该字段必填'})
    authors = serializers.CharField(required=False)

    # 局部钩子:
    def validate_name(self, value):
        # print(value)
        if value.startswith('sb'):
            # 不能以sb开头
            raise ValidationError('不能以sb开头')
        else:
            return value

    # 全局钩子找到了
    def validate(self, value):
        # value是所有校验通过数据的字典
        print(value)
        name = value.get('name')
        price = value.get('price')
        if name and price:
            if str(name) == str(price):
                return value
            else:
                raise ValidationError('名字跟价格不相等')
        return value

class BooksDetail(APIView):
    authentication_classes = [Auth, ]

    def get(self, request, pk):
        response = {'status': 100, 'msg': '成功'}
        ret = models.Book.objects.all().filter(pk=pk).first()
        # 生成一个序列化的对象,传参数
        # 序列化单,记住many=False
        if ret:
            book_ser = BookSerializer(ret, many=False)
            print(book_ser.data)
            response['data'] = book_ser.data
        else:
            response['status'] = 101
            response['msg'] = '您查询的不存在'

        return JsonResponse(response, safe=False)

    def put(self, request, pk):
        response = {'status': 100, 'msg': '成功'}
        ret = models.Book.objects.all().filter(pk=pk).first()
        if ret:
            # 数据校验
            # 传instance和不传instance,传instance的区别
            # 不传instance,调save(),往数据库新增数据
            # 传instance,调save(),修改数据
            ser = BookSerializer(data=request.data, instance=ret)
            if ser.is_valid():
                # ret.name=request.data.get('name')
                ser.save()
            else:
                response['status'] = 101
                response['msg'] = ser.errors
        else:
            response['status'] = 102
            response['msg'] = '修改的对象不存在'
        return JsonResponse(response, safe=False)

 

url(r'^books/(?P<pk>d+)$', views.Books_xx.as_view()),