rest-framework parser

A parser action:

　　Processing the request body content request content-type header parser according to the corresponding selected.

　　There application / json, x-www-form-urlencoded, form-data format　

   urlencoded: format body member is: name = & LQZ Age = 18 is & wife = liuyifei 
   FormData: file format of the data portion with the body portion being formed with a distinction 
   json format: json format in the body is the body

 

Two global use a parser:

In the settings.py

REST_FRAMEWORK = {
    'DEFAULT_PARSER_CLASSES':[
        'rest_framework.parsers.JSONParser'


        'rest_framework.parsers.FormParser'


        'rest_framework.parsers.MultiPartParser'
    ]

}

View layer:

from rest_framework.views Import APIView
 from rest_framework.response Import the Response 

class the TestView (APIView):
     DEF POST (Self, Request, * args, ** : kwargs)
         Print (request.content_type) 

        # JSONParser value acquisition request and using the corresponding processing 
        Print (request.data)
         # file application / time x-www-form-urlencoded or multipart / form-data, request.POST have value in 
        Print (of request.POST)
         Print (request.FILES)
         return the Response ( ' the POST request, response content ' ) 

    DEFPUT (Self, Request, * args, ** kwargs):
         return the Response ( ' the PUT request, response content ' )

Use a parser three parts:

Only the first request body processing request content-type application / json as the

from rest_framework.views Import APIView
 from rest_framework.response Import the Response
 from rest_framework.request Import the Request
 from rest_framework.parsers Import JSONParser 


class the TestView (APIView): 


    parser_classes = [JSONParser,] 


    DEF POST (Self, Request, * args, ** kwargs) :
         Print (request.content_type) 

        # acquires the requested value, and using the corresponding processing JSONParser 
        Print (request.data) 

        # when the application / x-www-form- urlencoded or multipart / form-data, request.POST only in value
        Print (of request.POST)
         Print (request.FILES) 

        return the Response ( ' the POST request, response content ' ) 

    DEF PUT (Self, Request, * args, ** kwargs):
         return the Response ( ' the PUT request, response content ' )

Request header request body content-type of application / x-www-form-urlencoded of

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)

Request header content-type of multipart / form-data of the request body

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)

upload files:

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, ]

At the same time more Parser

When using multiple parser, rest framework according to the request is compared to an automatic content-type header, and using a corresponding parser

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)

Four source code analysis:

1 when calling request.data, before parsing, thus starting 
    the @Property 
    DEF the Data (Self):
         IF  not _hasattr (Self, ' _full_data ' ): 
            self._load_data_and_files () 
        return self._full_data
        
 2 View self._load_data_and_files () method ----> self._data, self._files = self._parse () 

        DEF _parse (Self):
             # the value requested by the user in advance of content_type 
            MEDIA_TYPE = self.content_type 

            # self.parsers is user configurable parser_classes = [FileUploadParser , FormParser] 
            # Self in there content_type, passed into this function 
            parser =self.negotiator.select_parser (Self, self.parsers)

 3 View self.negotiator.select_parser (Self, self.parsers)
      DEF select_parser (Self, Request, parsers):
         # with over media_type and request.content_type comparison, the parser to return , then calls the parser analysis method 
        # each resolver has media_type = 'multipart / form-data ' attribute 
        for parser in parsers:
             IF media_type_matches (parser.media_type, request.content_type):
                 return parser
         return None
    
 . 4 eventually calls parser the analytical method to resolve parsed = parser.parse (stream, media_type, self.parser_context)

1 Request实例化，parsers=self.get_parsers()
    Request(
                request,
                parsers=self.get_parsers(),
                authenticators=self.get_authenticators(),
                negotiator=self.get_content_negotiator(),
                parser_context=parser_context
            )
2 get_parsers方法，循环实例化出self.parser_classes中类对象
    def get_parsers(self):
        return [parser() for parser in self.parser_classes]            

3self.parser_classes start to find the class itself, can not find the parent to find i.e. APIVIew in 
    parser_classes = api_settings.DEFAULT_PARSER_CLASSES
 . 4 api_settings is an object, the object was to find DEFAULT_PARSER_CLASSES properties not found, the method will be to getattr
         DEF  __getattr__ (Self, attr):
             IF attr Not  in self.defaults:
                 The raise AttributeError ( " Invalid Setting the API: '% S' " % attr) 

            the try :
                 # call self.user_settings method returns a dictionary, the dictionary then take attributes attr 
                Val = self.user_settings [attr]
             the except KeyError:
                # Fall the Back to Defaults 
                Val = self.defaults [attr] 

            # Coerce Import strings classes INTO 
            IF attr in self.import_strings: 
                Val = perform_import (Val, attr) 

            # Cache the Result at The 
            self._cached_attrs.add (attr) 
            setattr (Self, attr, Val) 
            return Val
  5 user_settings method, reflected by setting the configuration file to find REST_FRAMEWORK property, can not find, return empty dictionary 
    the @Property 
    DEF user_settings (Self):
         IF  not hasattr (Self, ' _user_settings ' ):
            self._user_settings = getattr(settings, 'REST_FRAMEWORK', {})
        return self._user_settings

Source process: 
   - When the call request.data to perform analytical method ---- "Select a parser object depending on the encoding pass over, call the parser object parser complete analytical method