• Django-restframework之路由控制、解析器及响应器


    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-datajson、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/jsonx-www-form-urlencodedform-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

    1. 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')
    
    1. 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')
    
    1. 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>
    
    1. 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>
    
    1. 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>
    
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  • 原文地址:https://www.cnblogs.com/zuanzuan/p/10441984.html
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