Rest_framework-3

目录：

• 返回值的封装
• 分页
• 视图
• 路由
• 渲染器

---

一 返回值的封装

a. API的基本框架

setting：

1 首先注册rest_framework

2 版本配置

REST_FRAMEWORK = {
    "DEFAULT_VERSIONING_CLASS":"rest_framework.versioning.URLPathVersioning",
    "VERSION_PARAM":"version",
    "ALLOWED_VERSIONS":['v1','v2'],
    "DEFAULT_VERSION":"v1",
}　　

urls.py：

from django.conf.urls import url,include
from django.contrib import admin

urlpatterns = [
    # url(r'^admin/', admin.site.urls),
    url(r'^api/(?P<version>[v1|v2]+)/',include('api.urls')),
]   # 路由分发

api路径：

from django.conf.urls import url,include
from django.contrib import admin
from api import views

urlpatterns = [
    url(r'^index/$',views.IndexView.as_view()),
]

views：

from rest_framework import views
from rest_framework.response import Response

class IndexView(views.APIView):
    def get(self,request,*args,**kwargs):

        return Response('...')

b.返回值封装的方法：　　

# 配置、路径与上相同

views视图：

from rest_framework import views
from rest_framework.response import Response

from api import models
from api.serializers.index import IndexSerializer

class BaseResponse(object):

    def __init__(self,code=1000,data=None,error=None):
        self.code = code
        self.data = data
        self.error = error

class IndexView(views.APIView):
    def get(self,request,*args,**kwargs):
        ret = BaseResponse()
        try:
            user_list = models.UserInfo.objects.all()
            ser = IndexSerializer(instance=user_list,many=True)

            ret.data = ser.data
        except Exception as e:
            ret.code = 1001
            ret.error = 'xxx错误'
        return Response(ret.__dict__)

对象方法

from rest_framework import views
from rest_framework.response import Response

from api import models
from api.serializers.index import IndexSerializer

class IndexView(views.APIView):
    def get(self,request,*args,**kwargs):
        ret = {'code': 1000,'data':None }
        try:
            user_list = models.UserInfo.objects.all()
            ser = IndexSerializer(instance=user_list,many=True)

            ret['data'] = ser.data
        except Exception as e:
            ret['code'] = 1001
            ret['error'] = 'xxx错误'
        return Response(ret) 

字典方法

# 创建serlalizers文件 存放序列化类的py文件

from rest_framework import serializers

class IndexSerializer(serializers.Serializer):
     id = serializers.IntegerField()
     name = serializers.CharField()
     pwd = serializers.CharField()

index

二 分页

分页最常见的三种情况：

1. 记录当前访问页的数据id

2. 最多显示120页

3. 对页码进行加密

a.基于limit offset做分页

自定义分页：

from rest_framework.pagination import LimitOffsetPagination

class P1(LimitOffsetPagination):

	max_limit = 3
	default_limit = 2
	limit_query_param = 'limit'
	offset_query_param = 'offset'

class IndexView(views.APIView):
	def get(self,request,*args,**kwargs):
		user_list = models.UserInfo.objects.all()
		p1 = P1()
		page_user_list = p1.paginate_queryset(queryset=user_list, request=request, view=self)
		ser = IndexSerializer(instance=page_user_list, many=True)
		return Response(ser.data) # 不含上一页和下一页
		# return p1.get_paginated_response(ser.data) # 含上一页和下一页

添加分页功能：

from rest_framework import views
from rest_framework.response import Response
from rest_framework.pagination import LimitOffsetPagination

from api import models
from api.serializers.index import IndexSerializer

class BaseResponse(object):

    def __init__(self,code=1000,data=None,error=None):
        self.code = code
        self.data = data
        self.error = error

class P1(LimitOffsetPagination):
    default_limit = 2  # 默认显示数据条数
    limit_query_param = 'limit'
    offset_query_param = 'offset'
    max_limit = 3  # 限制最大显示条数

class IndexView(views.APIView):
    def get(self,request,*args,**kwargs):
        ret = BaseResponse()
        try:
            user_list = models.UserInfo.objects.all()
            p1 = P1()
            page_user_list = p1.paginate_queryset(queryset=user_list,request=request,view=self)
            ser = IndexSerializer(instance=page_user_list,many=True)
            ret.data = ser.data
            ret.next = p1.get_next_link()
        except Exception as e:
            ret.code= 1001
            ret.error = 'xxxx错误'
        return Response(ret.__dict__)

示例

b.基于页码的分页

from rest_framework.pagination import  PageNumberPagination

class P2(PageNumberPagination):
	# 每页显示的数据条数
	max_page_size = 5
	page_size = 2
	page_size_query_param = 'size'

	# 页码
	page_query_param = 'page'

c.基于Cursor的分页（解决大数据分页的问题:页码加密）

from rest_framework.pagination import CursorPagination

class P3(CursorPagination):
	cursor_query_param = 'cursor'
	page_size = 2
	ordering = 'id'

ps：源码中不同的分页功能封装在不同的模块里，使用时可以根据需要将模块里的方法自定义，也可以配置在全局

三 视图

1. 基于APIView 自定义类

class IndexView(views.APIView):
	def get(self, request, *args, **kwargs):
		user_list = models.UserInfo.objects.all()
		ser = IndexSerializer(instance=user_list,many=True)
		return Response(ser.data)　

2. GenericAPIView(APIView)（过度作用）

3. GenericViewSet(ViewSetMixin, generics.GenericAPIView)

路由修改：
	urlpatterns = [
		url(r'^index/$', views.IndexView.as_view({'get':'list','post':'create'})),
		url(r'^index/(?P<pk>\d+)$', views.IndexView.as_view({'get':'retrieve'})),
	]

视图修改：
	class IndexView(viewsets.GenericViewSet):

		def list(self,request,*args,**kwargs):

			 pass # 获取列表信息

		def retrieve(self, request, *args, **kwargs):
			pass  # 获取单条数据

		def create(self,request, *args, **kwargs):
			pass  

4. ModelViewSet(mixins.CreateModelMixin,mixins.RetrieveModelMixin,mixins.UpdateModelMixin,mixins.DestroyModelMixin,mixins.ListModelMixin,GenericViewSet)

自定义类：
   class IndexView(ModelViewSet):

自定义：

增
POST
/users/
删
DELETE
/users/1/
改
PUT
/users/1/

patch
/users/1/
查
GET
/users/   # 全部数据
GET
/users/1/  # 单条数据

urlpatterns = [
    url(r'^index/$', views.IndexView.as_view()),
    url(r'^index/(?P<pk>\d+)$', views.IndexView.as_view()),
]

class IndexView(views.APIView):

    def get(self,request,*args,**kwargs):
        pk = kwargs.get('pk')
        if pk:
            pass # 获取单条信息
        else:
            pass # 获取列表信息

    def post(self,request,*args,**kwargs):
        pass

    def put(self,request,*args,**kwargs):
        pass

    def patch(self,request,*args,**kwargs):
        pass

    def delete(self,request,*args,**kwargs):
        pass
     

ps：工作中最常用第1种（完全自定义）和第4种（封装最多，需要那种方法就引用那种模块），第3种不常用

四 路由

第一类：

# http://127.0.0.1:8000/api/v1/auth/
url(r'^auth/$', views.AuthView.as_view()),

# http://127.0.0.1:8000/api/v1/auth.json # 想要让页面显示json格式
url(r'^auth\.(?P<format>[a-z0-9]+)$', views.AuthView.as_view()),

# http://127.0.0.1:8000/api/v1/auth/1/
url(r'^auth/(?P<pk>\d+)/$', views.AuthView.as_view()),

# http://127.0.0.1:8000/api/v1/auth/1.json
url(r'^auth/(?P<pk>\d+)\.(?P<format>[a-z0-9]+)$', views.AuthView.as_view()),

class AuthView(views.APIView):
	def get(self,request,*args,**kwargs):
		return Response('...')

第二类：

url(r'^index/$', views.IndexView.as_view({'get':'list','post':'create'})),

url(r'^index/\.(?P<format>[a-z0-9]+)$', views.IndexView.as_view({'get':'list','post':'create'})),

url(r'^index/(?P<pk>\d+)/$', views.IndexView.as_view({'get':'retrieve','delete':'destroy','put':'update','patch':'partial_update'})),

url(r'^index/(?P<pk>\d+)\.(?P<format>[a-z0-9]+)$', views.IndexView.as_view({'get':'retrieve','delete':'destroy','put':'update','patch':'partial_update'})),

class IndexView(viewsets.ModelViewSet):
	queryset = models.UserInfo.objects.all()
	serializer_class = IndexSerializer
	pagination_class = P2

第三类：（自动生成）　　

from rest_framework.routers import DefaultRouter
from rest_framework import views

router = DefaultRouter()
router.register('index',views.IndexViewSet)
urlpatterns = [
	url(r'^', include(router.urls)),
]

class IndexViewSet(viewsets.ModelViewSet):
	queryset = models.UserInfo.objects.all()
	serializer_class = IndexSerializer
	pagination_class = P2

class IndexSerializer(serializers.ModelSerializer):
	class Meta:
		model = models.UserInfo
		fields = "__all__"

五 渲染器

看到的页面是什么样子的，返回数据。

urls.py:

urlpatterns = [
    url(r'^index/$', views.IndexView.as_view()),
    url(r'^index\.(?P<format>[a-z0-9]+)$', views.IndexView.as_view()),
]

views.py

class IndexView(views.APIView):

    renderer_classes = [JSONRenderer,BrowsableAPIRenderer]

    def get(self,request,*args,**kwargs):
        self.dispatch
        user_list = models.UserInfo.objects.all()
        ser = IndexSerializer(instance=user_list,many=True)
        return Response(ser.data)

ps:通过路径后缀来决定返回页面的格式，默认是JSONRenderer模块，返回json字符串，