django-restframework之路由控制、解析器及响应器

一前言

本篇博客介绍 restframework 框架的剩下几个组件，路由控制有三种：传统路由、半自动路由及全自动路由；解析器是用来解析要响应的数据格式，比如是form-data、json、或是urlencoded等数据格式；响应器根据用户请求 url 或用户可以接受的数据格式来筛选出合适的渲染组件。

二路由控制

一传统路由

urls.py

from django.conf.urls import url

from app01 import views

urlpatterns = [

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

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

]

views.py

class BookView(APIView):

    def get(self, request):

        book_list = models.Book.objects.all()

        bs = BookSerializers(book_list, many=True)

        return Response(bs.data)

    def post(self, request):

        # 添加一条数据

        print(request.data)

        bs=BookSerializers(data=request.data)

        if bs.is_valid():

            bs.save()  # 生成记录

            return Response(bs.data)

        else:

            return Response(bs.errors)

class BookDetailView(APIView):

    def get(self,request,pk):

        book_obj=models.Book.objects.filter(pk=pk).first()

        bs=BookSerializers(book_obj,many=False)

        return Response(bs.data)

    def put(self,request,pk):

        book_obj = models.Book.objects.filter(pk=pk).first()

        bs=BookSerializers(data=request.data,instance=book_obj)

        if bs.is_valid():

            bs.save() # update

            return Response(bs.data)

        else:

            return Response(bs.errors)

    def delete(self,request,pk):

        models.Book.objects.filter(pk=pk).delete()

        return Response("")

二半自动路由（视图类继承 ModelViewSet）

原理就是重写 as_view方法，以致可以找到请求方法和响应视图方法的对应关系。

urls.py

from django.conf.urls import url

from app01 import views

urlpatterns = [

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

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

]

views.py

from rest_framework.viewsets import ModelViewSet

class PublishView(ModelViewSet):

    queryset=models.Publish.objects.all()

    serializer_class=PublishSerializers

三全自动路由（自动生成路由）

urls.py

from django.conf.urls import url,include

from app01 import views

from rest_framework import routers

router=routers.DefaultRouter()

# 两个参数，一个是匹配的路由，一个是视图中写的CBV的类

router.register('publish',views.PublishView)

urlpatterns = [

    # http://127.0.0.1:8000/publish/format=json(渲染器通过这个判断，返回渲染的页面)

    # url(r'^publish/', views.PublishView.as_view({'get':'list','post':'create'})),

    # http://127.0.0.1:8000/publish.json(渲染器通过这个判断，返回渲染的页面)

    # url(r'^publish\.(?P<format>\w+)$', views.PublishView.as_view({'get':'list','post':'create'})),

    # 可以用 以下方式访问

    # 1 http://127.0.0.1:8000/publish/

    # 2 http://127.0.0.1:8000/publish.json

    # 3 http://127.0.0.1:8000/publish/3

    # 4 http://127.0.0.1:8000/publish/3.json

    url(r'',include(router.urls))

]

views.py

from rest_framework.viewsets import ModelViewSet

class PublishView(ModelViewSet):

    queryset=models.Publish.objects.all()

    serializer_class=PublishSerializers

三解析器

一解析器的作用

根据请求头的Content-Type参数来选择对应的解析器对请求体内容进行处理，有application/json、x-www-form-urlencoded、form-data等格式。

二全局使用解析器

settings.py

REST_FRAMEWORK = {

    'DEFAULT_PARSER_CLASSES':[

        'rest_framework.parsers.JSONParser'

        'rest_framework.parsers.FormParser'

        'rest_framework.parsers.MultiPartParser'

    ]

}

urls.py

urlpatterns = [

    url(r'test/', TestView.as_view()),

]

views.py

from rest_framework.views import APIView

from rest_framework.response import Response

class TestView(APIView):

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

        print(request.content_type)

        # 获取请求的值，并使用对应的JSONParser进行处理

        print(request.data)

        # application/x-www-form-urlencoded 或 multipart/form-data时，request.POST中才有值

        print(request.POST)

        print(request.FILES)

        return Response('POST请求，响应内容')

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

        return Response('PUT请求，响应内容')

三局部使用解析器

仅处理请求头 content-type 为 application/json 的请求体

urls.py

from django.conf.urls import url, include

from web.views.s5_parser import TestView

urlpatterns = [

    url(r'test/', TestView.as_view(), name='test'),

]

views.py

from rest_framework.views import APIView

from rest_framework.response import Response

from rest_framework.request import Request

from rest_framework.parsers import JSONParser

class TestView(APIView):

    # 局部配置该参数

    parser_classes = [JSONParser, ]

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

        print(request.content_type)

        # 获取请求的值，并使用对应的JSONParser进行处理

        print(request.data)

        # application/x-www-form-urlencoded 或 multipart/form-data时，request.POST中才有值

        print(request.POST)

        print(request.FILES)

        return Response('POST请求，响应内容')

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

        return Response('PUT请求，响应内容')

仅处理请求头 content-type 为 application/x-www-form-urlencoded 的请求体

urls.py

from django.conf.urls import url, include

from web.views import TestView

urlpatterns = [

    url(r'test/', TestView.as_view(), name='test'),

]

views.py

from rest_framework.views import APIView

from rest_framework.response import Response

from rest_framework.request import Request

from rest_framework.parsers import FormParser

class TestView(APIView):

    parser_classes = [FormParser, ]

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

        print(request.content_type)

        # 获取请求的值，并使用对应的JSONParser进行处理

        print(request.data)

        # application/x-www-form-urlencoded 或 multipart/form-data时，request.POST中才有值

        print(request.POST)

        print(request.FILES)

        return Response('POST请求，响应内容')

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

        return Response('PUT请求，响应内容')

仅处理请求头 content-type 为 multipart/form-data 的请求体

urls.py

from django.conf.urls import url, include

from web.views import TestView

urlpatterns = [

    url(r'test/', TestView.as_view(), name='test'),

]

views.py

from rest_framework.views import APIView

from rest_framework.response import Response

from rest_framework.request import Request

from rest_framework.parsers import MultiPartParser

class TestView(APIView):

    parser_classes = [MultiPartParser, ]

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

        print(request.content_type)

        # 获取请求的值，并使用对应的JSONParser进行处理

        print(request.data)

        # application/x-www-form-urlencoded 或 multipart/form-data时，request.POST中才有值

        print(request.POST)

        print(request.FILES)

        return Response('POST请求，响应内容')

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

        return Response('PUT请求，响应内容')

html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

</head>

<body>

<form action="http://127.0.0.1:8000/test/" method="post" enctype="multipart/form-data">

    <input type="text" name="user" />

    <input type="file" name="img">

    <input type="submit" value="提交">

</form>

</body>

</html>

仅上传文件

urls.py

from django.conf.urls import url, include

from web.views import TestView

urlpatterns = [

    url(r'test/(?P<filename>[^/]+)', TestView.as_view(), name='test'),

]

views.py

from rest_framework.views import APIView

from rest_framework.response import Response

from rest_framework.request import Request

from rest_framework.parsers import FileUploadParser

class TestView(APIView):

    parser_classes = [FileUploadParser, ]

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

        print(filename)

        print(request.content_type)

        # 获取请求的值，并使用对应的JSONParser进行处理

        print(request.data)

        # application/x-www-form-urlencoded 或 multipart/form-data时，request.POST中才有值

        print(request.POST)

        print(request.FILES)

        return Response('POST请求，响应内容')

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

        return Response('PUT请求，响应内容')

html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

</head>

<body>

<form action="http://127.0.0.1:8000/test/f1.numbers" method="post" enctype="multipart/form-data">

    <input type="text" name="user" />

    <input type="file" name="img">

    <input type="submit" value="提交">

</form>

</body>

</html>

同时多个 parser

当同时使用多个 parser 时，restframework 会根据请求头 content-ty 自动进行对应，并使用相应的 parset

urls.py

from django.conf.urls import url, include

from web.views import TestView

urlpatterns = [

    url(r'test/', TestView.as_view(), name='test'),

]

views.py

from rest_framework.views import APIView

from rest_framework.response import Response

from rest_framework.request import Request

from rest_framework.parsers import JSONParser, FormParser, MultiPartParser

class TestView(APIView):

    parser_classes = [JSONParser, FormParser, MultiPartParser, ]

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

        print(request.content_type)

        # 获取请求的值，并使用对应的JSONParser进行处理

        print(request.data)

        # application/x-www-form-urlencoded 或 multipart/form-data时，request.POST中才有值

        print(request.POST)

        print(request.FILES)

        return Response('POST请求，响应内容')

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

        return Response('PUT请求，响应内容')

四解析器源码分析

当调用request.data时才进行解析数据，这里的 request 是Request类对象。

1. request.data

2. request._load_data_and_files

3. request._parse

4. request._stream

5. self.parsers

6. self.parser_classes

self.parser_classes就是设置在视图类中的一个列表

7. self.negotiator.select_parser

根据数据格式选择对应的数据解析器

8. self.get_parser_context

9. stream、media_type和 self.parser_context准备好

10. 假设该解析器为 JSONParser

四响应器

一作用

根据用户请求的 URL 或用户可接受的数据类型，筛选出合适的渲染组件。

用户请求 URL：

二内置渲染器

显示 json 格式：JSONRenderer

访问 url：

默认显示格式：BrowsableAPIRenderer（可以修改 html 文件）

访问 url：

表格方式：AdminRenderer

访问 url：

form 表单方式：HTMLFormRenderer

访问 url：

三局部使用

from rest_framework.renderers import  HTMLFormRenderer,BrowsableAPIRenderer

class BookDetailView(APIView):

    renderer_classes = [HTMLFormRenderer,BrowsableAPIRenderer ]

    def get(self,request,pk):

        book_obj=models.Book.objects.filter(pk=pk).first()

        bs=BookSerializers(book_obj,many=False)

        return Response(bs.data)

    def put(self,request,pk):

        book_obj = models.Book.objects.filter(pk=pk).first()

        bs=BookSerializers(data=request.data,instance=book_obj)

        if bs.is_valid():

            bs.save() # update

            return Response(bs.data)

        else:

            return Response(bs.errors)

    def delete(self,request,pk):

        models.Book.objects.filter(pk=pk).delete()

        return Response("")

四全局使用

REST_FRAMEWORK = {

    'DEFAULT_RENDERER_CLASSES':['rest_framework.renderers.JSONRenderer']

}

五自定义显示模板

views.py

from rest_framework.renderers import  TemplateHTMLRenderer

class BookDetailView(APIView):

    renderer_classes = [TemplateHTMLRenderer]

    def get(self,request,pk):

        book_obj=models.Book.objects.filter(pk=pk).first()

        bs=BookSerializers(book_obj,many=False)

        return Response(bs.data,template_name='aa.html')

html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Title</title>

</head>

<body>

{{ title }}

{{ publishDate }}

</body>

</html>