Django REST framework序列化
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
models部分
from django.db import models
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
view部分
from django.views import View
from rest_framework.response import Response
from app01.serializer import *
from rest_framework.views import APIView
class PublishView(APIView):
def get(self, request):
# 序列化方式
# 方式1：
# publish_list=list(Publish.objects.all().values("name","email"))
# 方式2：
# model_to_dict就是把一个model对象转换成字典
# 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))
# 方式3：
# django的序列化组件，跟restful没关系，最简单的方式
# from django.core import serializers
# ret=serializers.serialize("json",publish_list)
# 方式4：
# DjangoRESTframework序列组件，详见serializer部分
# 实例化一个序列化对象，传入要序列化的数据和many
# many=True表示传入的是一个queryset，false是model对象
publish_list = Publish.objects.all()
ps = PublishModelSerializers(publish_list, many=True)
# 取序列化后的数据
return Response(ps.data)
# restframework中get取数据
# print("request.data", request.data)
# print("request.data type", type(request.data))
# print(request._request.GET)
# print(request.GET)
serializer部分
from rest_framework import serializers
from app01.models import *
# 类1： 为queryset,model对象做序列化
# 对哪些字段做序列化name = serializers.CharField() 这个字段序列化成什么类型
class PublishSerializers(serializers.Serializer):
name = serializers.CharField()
email = serializers.CharField()
# 类2： 上面的方式需要自己定义字段，faramework组件也有一个类似modelform的组件
class PublishModelSerializers(serializers.ModelSerializer):
class Meta:
model = Publish
fields = "__all__"
# 类1中只设置了一些简单的字段，下面是一对多，多对多的字段时的方法
# class BookSerializers(serializers.Serializer):
# title = serializers.CharField(max_length=32)
# price = serializers.IntegerField()
# pub_date = serializers.DateField()
# publish=serializers.CharField(source="publish.name")
# #authors=serializers.CharField(source="authors.all")
# authors = serializers.SerializerMethodField()
# def get_authors(self,obj):
# temp=[]
# for obj in obj.authors.all():
# temp.append(obj.name)
# return temp
'''
序列化BookSerializers(book_list,many=True)过程：
temp=[]
for obj in book_list:
temp.append({
"title":obj.title,
"price":obj.price,
"pub_date":obj.pub_date,
"publish":str(obj.publish), # obj.publish.name
#"authors":obj.authors.all,
"authors": get_authors(obj)
})
'''
ModelSerializer
上面的类2就用的ModelSerializer
class BookSerializers(serializers.ModelSerializer):
class Meta:
model=Book
fields="__all__"
depth=1
处理POST请求
def post(self, request):
# 取数据,原生request支持的操作，如果contenttype其它的原生request不会帮你封装
# print("POST",request.POST)
# print("body",request.body)
# # print(request)
# print(type(request))
# from django.core.handlers.wsgi import WSGIRequest
# 新的request支持的操作
# print("request.data",request.data)
# print("request.data type",type(request.data))
# post请求的数据
ps = PublishModelSerializers(data=request.data, many=False)
if ps.is_valid():
print(ps.validated_data)
ps.save() # create方法
return Response(ps.data)
else:
return Response(ps.errors)
重写save中的create方法
class BookModelSerializers(serializers.ModelSerializer):
class Meta:
model = Book
fields = "__all__"
# authors=serializers.CharField(source="authors.all")
authors = serializers.SerializerMethodField()
def get_authors(self,obj):
temp=[]
for obj in obj.authors.all():
temp.append(obj.name)
return temp
# 假如你上面自定义了字段的显示，就需要重写create方法了
def create(self, validated_data):
authors = validated_data.pop('authors')
book =Book.objects.create(**validated_data)
book.authors.add(*authors)
return book
单条数据的get、put、delete请求
class PublishDetailView(APIView):
def get(self, request, pk):
publish = Publish.objects.filter(pk=pk).first()
ps = PublishModelSerializers(publish)
return Response(ps.data)
def put(self, request, pk):
publish = Publish.objects.filter(pk=pk).first()
ps = PublishModelSerializers(publish, data=request.data)
if ps.is_valid():
ps.save()
return Response(ps.data)
else:
return Response(ps.errors)
def delete(self, request, pk):
Publish.objects.filter(pk=pk).delete()
return Response()
超链接API：Hyperlinked
很多时候，我们就想一个字段的值是另一个字段的超链接，如下book表的publish字段就是publish表的超链接
class BookModelSerializers(serializers.ModelSerializer):
class Meta:
model = Book
fields = "__all__"
publish = serializers.HyperlinkedIdentityField(
# 你要找的url的别名
view_name="detailpublish",
# 含正则表达式如(\d+)的话，下两步是把什么字段的内容，赋值给哪个分组命名
lookup_field="publish_id",
# 赋给什么分组命名
lookup_url_kwarg="pk"
)
urls部分
urlpatterns = [
# View:view(request)=====APIView:dispatch()
url(r'^publishes/$', views.PublishView.as_view(), name="publish"),
url(r'^publishes/(?P<pk>\d+)/$', views.PublishDetailView.as_view(), name="detailpublish"),
# View:view(request)=====APIView:dispatch()
url(r'^books/$', views.BookView.as_view(), name="books"),
url(r'^books/(\d+)/$', views.BookDetailView.as_view(), name="detailbook"),
]
小结
# 需要会的：
restframework(Django) ----针对数据：json (1)Django的原生request: 浏览器 ------------- 服务器 "GET url?a=1&b=2 http/1.1\r\user_agent:Google\r\ncontentType:urlencoded\r\n\r\n" "POST url http/1.1\r\user_agent:Google\r\ncontentType:urlencoded\r\n\r\na=1&b=2"
# post请求才有请求体，get没有请求体 request.body: a=1&b=2 request.POST: if contentType:urlencoded: # 才会给你封装 a=1&b=2----->{"a":1,"b":2}
(2)restframework 下的APIView： (3) class PublishSerializers(serializers.Serializer): name=serializers.CharField() email=serializers.CharField() PublishSerializers(queryset,many=true) PublishSerializers(model_obj) 总结： 1 reuqest类----源码 2 restframework 下的APIView--源码 url(r'^books/$', views.BookView.as_view(),name="books")# View下的view books/一旦被访问： view(request) ------APIView: dispatch() 3 def dispatch(): 构建request对象 self.request=Request(request) self.request._request self.request.GET # get self.request.data # POST PUT 分发----if get请求： if request.method.lower() in self.http_method_names: handler = getattr(self, request.method.lower(), self.http_method_not_allowed) else: handler = self.http_method_not_allowed response = handler(request, *args, **kwargs) # self.get(request, *args, **kwargs) return response 4 序列化类 # from django.core import serializers # ret=serializers.serialize("json",publish_list) restframework下的序列类 BookModelSerializers 将queryset或者model对象序列成一json数据 bs=BookModelSerializers(book_list,many=True,context={'request': request}) bs=BookModelSerializers(book,context={'request': request}) 还可以做校验数据，json-------》queryset/model-->记录 bs=BookModelSerializers(data=request.data) if bs.is_valid(): print(bs.validated_data) bs.save() # 重写create方法 5 操作数据： 以Book表为例 class BookView(APIView): # 查看所有书籍 def get(self,request): book_list=Book.objects.all() bs=BookModelSerializers(book_list,many=True,context={'request': request}) return Response(bs.data) # 添加一本书籍 def post(self,request): # post请求的数据 bs=BookModelSerializers(data=request.data) if bs.is_valid(): print(bs.validated_data) bs.save()# create方法 return Response(bs.data) else: return Response(bs.errors) class BookDetailView(APIView): # 查看一本书籍 def get(self,request,id): book=Book.objects.filter(pk=id).first() bs=BookModelSerializers(book,context={'request': request}) return Response(bs.data) # 更新一本书籍 def put(self,request,id): book=Book.objects.filter(pk=id).first() bs=BookModelSerializers(book,data=request.data) if bs.is_valid(): bs.save() return Response(bs.data) else: return Response(bs.errors) # 删除某一本书籍 def delete(self,request,id): Book.objects.filter(pk=id).delete() return Response() restframework 1 APIView 2 序列组件 3 视图、 4 组件（认证权限频率） 5 数据解析器 6 分页和Response