rest-framework组件 之 序列化
浏览目录
restful协议
一切皆是资源，操作只是请求方式。
rest-framework
针对数据：json数据。
创建一个序列化类
简单使用
开发我们的Web API的第一件事是为我们的Web API提供一种将代码片段实例序列化和反序列化为诸如json之类的表示形式的方式。我们可以通过声明与Django forms非常相似的序列化器（serializers）来实现。
models
from django.db import models
# Create your models here.
class Book(models.Model):
title=models.CharField(max_length=32)
price=models.IntegerField()
pub_date=models.DateField()
publish=models.ForeignKey("Publish")
authors=models.ManyToManyField("Author")
def __str__(self):
return self.title
class Publish(models.Model):
name=models.CharField(max_length=32)
email=models.EmailField()
def __str__(self):
return self.name
class Author(models.Model):
name=models.CharField(max_length=32)
age=models.IntegerField()
def __str__(self):
return self.name
views
from django.views import View
from .models import *
class PublishView(View):
def get(self,request):
# 序列化方式一
# publish_list=list(Publish.objects.all().values("id","name","email")) #queryset不能进行序列化，强转为list。
# return HttpResponse(json.dumps(publish_list)) #转化为json字符串
# 结果：[{"name": "\u82f9\u679c\u51fa\u7248\u793e", "email": "123@qq.com", "id": 1},
# {"name": "\u6843\u5b50\u51fa\u7248\u793e", "email": "456@qq.com", "id": 2}]
# 序列化方式二
# publish_list=Publish.objects.all()
# temp=[]
# for obj in publish_list:
# temp.append({
# "id":obj.pk,
# "name":obj.name,
# "email":obj.email
# })
# return HttpResponse(json.dumps(temp))
# 结果：[{"id": 1, "name": "\u82f9\u679c\u51fa\u7248\u793e", "email": "123@qq.com"},
# {"id": 2, "name": "\u6843\u5b50\u51fa\u7248\u793e", "email": "456@qq.com"}]
# 以上方式优化
# from django.forms.models import model_to_dict
# publish_list = Publish.objects.all()
# temp = []
# for obj in publish_list:
# temp.append(model_to_dict(obj))
# 序列化方式三
from django.core import serializers #django的序列化组件
publish_list = Publish.objects.all()
ret=serializers.serialize("json",publish_list)
return HttpResponse(ret)
# 结果：
# [{"model": "app01.publish", "pk": 1, "fields": {"name": "\u82f9\u679c\u51fa\u7248\u793e", "email": "123@qq.com"}},
# {"model": "app01.publish", "pk": 2, "fields": {"name": "\u6843\u5b50\u51fa\u7248\u793e", "email": "456@qq.com"}}]
我们来看一下如何用rest-framework进行序列化。
from django.core import serializers
from .models import *
from rest_framework.response import Response
from rest_framework import serializers
from rest_framework.views import APIView
# 为queryset，model对象做序列化
# 实例化一个类
class PublishSerializers(serializers.Serializer):
# 需要序列化的字段
name=serializers.CharField()
email=serializers.CharField()
class PublishView(APIView):
def get(self,request):
# 方式四：restframework
publish_list = Publish.objects.all()
ps = PublishSerializers(publish_list, many=True) #实例化一个对象
return Response(ps.data)
# 结果：[{"name":"苹果出版社","email":"123@qq.com"},{"name":"桃子出版社","email":"456@qq.com"}]
注意：如果是对queryset做序列化，就要加many=True.如果是对model对象做序列化，就是many=False.默认为false,可以不用写。
实例化的时候要是数据是一个 queryset 我们要加 many = True ret = PublishSerializers(publish_list, many=True) ret.data ------------------------------------拿到的是一个OrderDict。
实例化的时候要是数据是一个model对象，many默认是一个False（可以不写） ret = PublishSerializers(obj) ret.data ------------------------------------拿到的是一个字典
ModelSerializer
class BookSerializers(serializers.ModelSerializer):
class Meta:
model=Book
fields="__all__"
depth=1
提交post请求
def post(self,request,*args,**kwargs):
bs=BookSerializers(data=request.data,many=False)
if bs.is_valid():
# print(bs.validated_data)
bs.save()
return Response(bs.data)
else:
return HttpResponse(bs.errors)
重写save的create方法
class BookSerializers(serializers.ModelSerializer):
class Meta:
model=Book
fields="__all__"
# exclude = ['authors',]
# depth=1
def create(self, validated_data):
authors = validated_data.pop('authors')
obj = Book.objects.create(**validated_data)
obj.authors.add(*authors)
return obj
单条数据的get和put请求
class BookDetailViewSet(APIView):
def get(self,request,pk):
book_obj=Book.objects.filter(pk=pk).first()
bs=BookSerializers(book_obj)
return Response(bs.data)
def put(self,request,pk):
book_obj=Book.objects.filter(pk=pk).first()
bs=BookSerializers(book_obj,data=request.data)
if bs.is_valid():
bs.save()
return Response(bs.data)
else:
return HttpResponse(bs.errors)
超链接API
class BookSerializers(serializers.ModelSerializer):
publish= serializers.HyperlinkedIdentityField(
view_name='publish_detail',
lookup_field="publish_id",
lookup_url_kwarg="pk")
class Meta:
model=Book
fields="__all__"
#depth=1
urls
urlpatterns = [
url(r'^books/$', views.BookViewSet.as_view(),name="book_list"),
url(r'^books/(?P<pk>\d+)$', views.BookDetailViewSet.as_view(),name="book_detail"),
url(r'^publishers/$', views.PublishViewSet.as_view(),name="publish_list"),
url(r'^publishers/(?P<pk>\d+)$', views.PublishDetailViewSet.as_view(),name="publish_detail"),
]
总结：
1、queryset对象不能进行序列化。
