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-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

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：

• http://127.0.0.1:8000/test/?format=json
• http://127.0.0.1:8000/test.json

二内置渲染器

显示 json 格式：JSONRenderer

访问 url：

• http://127.0.0.1:8000/test/?format=json
• http://127.0.0.1:8000/test.json
• http://127.0.0.1:8000/test/

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

访问 url：

• http://127.0.0.1:8000/test/?format=api
• http://127.0.0.1:8000/test.api
• http://127.0.0.1:8000/test/

表格方式：AdminRenderer

访问 url：

• http://127.0.0.1:8000/test/format=admin
• http://127.0.0.1:8000/test.admin
• http://127.0.0.1:8000/test/

form 表单方式：HTMLFormRenderer

访问 url：

• http://127.0.0.1:8000/test/?format=form
• http://127.0.0.1:8000/test.form
• http://127.0.0.1:8000/test/

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>