rest framework 之解析器

时间：2024-07-11 15:36:32

一、示例

1、api/urls.py

from django.urls import path, re_path

from api.views import UserView, ParserView

urlpatterns = [

    # path('users/', UserView.as_view()),

    re_path('(?P<version>[v1|v2]+)/users/', UserView.as_view(), name='api_user'),

    path('parser/', ParserView.as_view(), name='api_parer'),		# 添加这句

]

2、api/views.py

  • JSONParser：只能解析content-type:application/json的头
  • FormParser：只能解析content-type:application/x-www-form-urlencoded的头
from rest_framework.parsers import JSONParser, FormParser

class ParserView(APIView):

    parser_classes = [JSONParser, FormParser]

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

        print(request.data)

        return HttpResponse('解析')

3、使用 postman 发送 json 数据测试后台是否能解析：

（1）、设置为 post 方式，headers 中添加数据类型为 json

rest framework 之解析器

（2）、body 中选择 raw，然后选择 json 类型，最后就是在空白处构建要发送的 json 数据（记得是双引号）：

rest framework 之解析器

后台结果：

rest framework 之解析器

如果是 content-type:application/x-www-form-urlencoded 类型数据，不需要设置请求头，默认就是。但是 body 中需要设置为 x-www-form-urlencoded 。

二、源码分析

1、dispatch()

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

    """

    `.dispatch()` is pretty much the same as Django's regular dispatch,

    but with extra hooks for startup, finalize, and exception handling.

    """

    self.args = args

    self.kwargs = kwargs

    # 对原生的 request 对象进行加工，丰富了

    # request= Request(request,parsers=self.get_parsers(),authenticators=self.get_authenticators(),negotiator=self.get_content_negotiator(),parser_context=parser_context)

    # 第一个参数为原生的 request 对象，封装原生 request

    request = self.initialize_request(request, *args, **kwargs)

    self.request = request

    self.headers = self.default_response_headers  # deprecate?

    try:

        self.initial(request, *args, **kwargs)

        # Get the appropriate handler method

        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)

    except Exception as exc:

        response = self.handle_exception(exc)

        self.response = self.finalize_response(request, response, *args, **kwargs)

        return self.response

2、initialize_request()

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

    """

    Returns the initial request object. 封装原生 request 对象

    """

    parser_context = self.get_parser_context(request)

    return Request(

        request,

        # 获取所有解析器

        parsers=self.get_parsers(),

        authenticators=self.get_authenticators(),

        negotiator=self.get_content_negotiator(),

        parser_context=parser_context

    )

3、get_parsers()

def get_parsers(self):

    """

    Instantiates and returns the list of parsers that this view can use.

    返回次视图可以使用的解析器列表

    """

    return [parser() for parser in self.parser_classes]

4、parser_classes

class APIView(View):

    # The following policies may be set at either globally, or per-view.

    renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES

    # 从 settings 中获取解析器

    parser_classes = api_settings.DEFAULT_PARSER_CLASSES

    # Allow dependency injection of other settings to make testing easier.

    settings = api_settings

5、全局配置解析器 settings：

REST_FRAMEWORK = {

    # 解析器

    "DEFAULT_PARSER_CLASSES":["rest_framework.parsers.JSONParser","rest_framework.parsers.FormParser"]

}

源码流程图

rest framework 之解析器

根据请求头 content-type 选择对应的解析器就请求体内容进行处理。

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

1、urls.py

from django.urls import path, re_path, include

from api.views import TestView2

urlpatterns = [

    re_path(r'(?P<version>[v1|v2]+)/test2', TestView2.as_view()),

]

2、views.py

rom rest_framework.views import APIView

from rest_framework.parsers import JSONParser, FormParser

from rest_framework.response import Response

class TestView2(APIView):

    parser_classes = [JSONParser]

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

        print(request.content_type)    # application/json

        # 获取请求值，并发 JSONParser  处理

        print(request.data)     # {'name': 'rose', 'age': 18}

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

        print(request.POST)         # <QueryDict: {}>

        print(request.FILES)        # <MultiValueDict: {}>

        return Response('响应内容')

rest framework 之解析器

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

1、urls.py

from django.urls import path, re_path, include

from api.views import TestView2

urlpatterns = [

    re_path(r'(?P<version>[v1|v2]+)/test2', TestView2.as_view()),

]

2、views.py

rom rest_framework.views import APIView

from rest_framework.parsers import JSONParser, FormParser

from rest_framework.response import Response

class TestView2(APIView):

    parser_classes = [FormParser]

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

        print(request.content_type)    # application/x-www-form-urlencoded

        # 获取请求值，并发 JSONParser  处理

        print(request.data)     # <QueryDict: {'123': ['']}>

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

        print(request.POST)         # <QueryDict: {'123': ['']}>

        print(request.FILES)        # <MultiValueDict: {}>

        return Response('响应内容')

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

1、urls.py

from django.urls import path, re_path, include

from api.views import TestView2

urlpatterns = [

    re_path(r'(?P<version>[v1|v2]+)/test2', TestView2.as_view()),

]

2、views.py

rom rest_framework.views import APIView

from rest_framework.parsers import JSONParser, FormParser, MultiPartParser

from rest_framework.response import Response

class TestView2(APIView):

    parser_classes = [MultiPartParser]

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

        print(request.content_type)    # multipart/form-data

        # 获取请求值，并发 JSONParser  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('响应内容')

3、upload.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>

六、仅上传文件

1、urls.py

from django.urls import path, re_path, include

from api.views import TestView2

urlpatterns = [

    re_path(r'(?P<version>[v1|v2]+)/test2', TestView2.as_view()),

]

2、views.py

rom rest_framework.views import APIView

from rest_framework.parsers import JSONParser, FormParser, MultiPartParser, FileUploadParser

from rest_framework.response import Response

class TestView2(APIView):

    parser_classes = [FileUploadParser]

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

        print(request.content_type)    

        # 获取请求值，并发 JSONParser  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('响应内容')

3、upload.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>

七、其他

多个 parser

当同时使用多个 parser 时，rest framework 会根据请求头 content-type 自动进行比对，并使用对应 parser

#!/usr/bin/env python

# -*- coding:utf-8 -*-

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')

全局使用

settings.py

REST_FRAMEWORK = {

    'DEFAULT_PARSER_CLASSES':[

        'rest_framework.parsers.JSONParser'

        'rest_framework.parsers.FormParser'

        'rest_framework.parsers.MultiPartParser'

    ]

}

Tips: 个别特殊的值可以通过Django的request对象 request._request 来进行获取

总结

  • JSONParser，解析数据类型：content-type:application/json
  • FormParser，解析数据类型：content-type:application/x-www-form-urlencoded
  • 支持全局配置解析器类型

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