一 解析器的作用
根據請求頭 content-type 選擇對應的解析器對請求體內容進行處理。
有application/json，x-www-form-urlencoded，form-data等格式
二 全局使用解析器
setting里
REST_FRAMEWORK = { 'DEFAULT_PARSER_CLASSES':[ 'rest_framework.parsers.JSONParser' 'rest_framework.parsers.FormParser' 'rest_framework.parsers.MultiPartParser' ] }
路由：
urlpatterns = [ url(r'test/', TestView.as_view()), ]
視圖函數：
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) # 獲取請求的值，並使用對應的JSONParser進行處理 print(request.data) # application/x-www-form-urlencoded 或 multipart/form-data時，request.POST中才有值 print(request.POST) print(request.FILES) return Response('POST請求，響應內容') def put(self, request, *args, **kwargs): return Response('PUT請求，響應內容')
三 局部使用解析器
a. 僅處理請求頭content-type為application/json的請求體
from django.conf.urls import url, include from web.views.s5_parser import TestView urlpatterns = [ url(r'test/', TestView.as_view(), name='test'), ]
#!/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 class TestView(APIView): parser_classes = [JSONParser, ] def post(self, request, *args, **kwargs): print(request.content_type) # 獲取請求的值，並使用對應的JSONParser進行處理 print(request.data) # application/x-www-form-urlencoded 或 multipart/form-data時，request.POST中才有值 print(request.POST) print(request.FILES) return Response('POST請求，響應內容') def put(self, request, *args, **kwargs): return Response('PUT請求，響應內容')
b. 僅處理請求頭content-type為application/x-www-form-urlencoded 的請求體
from django.conf.urls import url, include from web.views import TestView urlpatterns = [ url(r'test/', TestView.as_view(), name='test'), ]
#!/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 FormParser class TestView(APIView): parser_classes = [FormParser, ] def post(self, request, *args, **kwargs): print(request.content_type) # 獲取請求的值，並使用對應的JSONParser進行處理 print(request.data) # application/x-www-form-urlencoded 或 multipart/form-data時，request.POST中才有值 print(request.POST) print(request.FILES) return Response('POST請求，響應內容') def put(self, request, *args, **kwargs): return Response('PUT請求，響應內容')
c. 僅處理請求頭content-type為multipart/form-data的請求體
from django.conf.urls import url, include from web.views import TestView urlpatterns = [ url(r'test/', TestView.as_view(), name='test'), ]
#!/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 MultiPartParser class TestView(APIView): parser_classes = [MultiPartParser, ] def post(self, request, *args, **kwargs): print(request.content_type) # 獲取請求的值，並使用對應的JSONParser進行處理 print(request.data) # application/x-www-form-urlencoded 或 multipart/form-data時，request.POST中才有值 print(request.POST) print(request.FILES) return Response('POST請求，響應內容') def put(self, request, *args, **kwargs): return Response('PUT請求，響應內容')
<!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>
d. 僅上傳文件
from django.conf.urls import url, include from web.views import TestView urlpatterns = [ url(r'test/(?P<filename>[^/]+)', TestView.as_view(), name='test'), ]
#!/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 FileUploadParser class TestView(APIView): parser_classes = [FileUploadParser, ] def post(self, request, filename, *args, **kwargs): print(filename) print(request.content_type) # 獲取請求的值，並使用對應的JSONParser進行處理 print(request.data) # application/x-www-form-urlencoded 或 multipart/form-data時，request.POST中才有值 print(request.POST) print(request.FILES) return Response('POST請求，響應內容') def put(self, request, *args, **kwargs): return Response('PUT請求，響應內容')
<!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>
e. 同時多個Parser
當同時使用多個parser時，rest framework會根據請求頭content-type自動進行比對，並使用對應parser
from django.conf.urls import url, include from web.views import TestView urlpatterns = [ url(r'test/', TestView.as_view(), name='test'), ]
#!/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) # 獲取請求的值，並使用對應的JSONParser進行處理 print(request.data) # application/x-www-form-urlencoded 或 multipart/form-data時，request.POST中才有值 print(request.POST) print(request.FILES) return Response('POST請求，響應內容') def put(self, request, *args, **kwargs): return Response('PUT請求，響應內容')
四 源碼分析
1 在調用request.data時，才進行解析，由此入手 @property def data(self): if not _hasattr(self, '_full_data'): self._load_data_and_files() return self._full_data 2 查看self._load_data_and_files()方法---->self._data, self._files = self._parse() def _parse(self): #用戶請求頭里content_type的值 media_type = self.content_type #self.parsers 就是用戶配置的parser_classes = [FileUploadParser,FormParser ] #self里就有content_type，傳入此函數 parser = self.negotiator.select_parser(self, self.parsers) 3 查看self.negotiator.select_parser(self, self.parsers) def select_parser(self, request, parsers): #同過media_type和request.content_type比較，來返回解析器，然后調用解析器的解析方法 #每個解析器都有media_type = 'multipart/form-data'屬性 for parser in parsers: if media_type_matches(parser.media_type, request.content_type): return parser return None 4 最終調用parser的解析方法來解析parsed = parser.parse(stream, media_type, self.parser_context)
1 Request實例化，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，循環實例化出self.parser_classes中類對象 def get_parsers(self): return [parser() for parser in self.parser_classes] 3 self.parser_classes 先從類本身找，找不到去父類找即APIVIew 中的 parser_classes = api_settings.DEFAULT_PARSER_CLASSES 4 api_settings是一個對象，對象里找DEFAULT_PARSER_CLASSES屬性，找不到，會到getattr方法 def __getattr__(self, attr): if attr not in self.defaults: raise AttributeError("Invalid API setting: '%s'" % attr) try: #調用self.user_settings方法，返回一個字典，字典再取attr屬性 val = self.user_settings[attr] except KeyError: # Fall back to defaults val = self.defaults[attr] # Coerce import strings into classes if attr in self.import_strings: val = perform_import(val, attr) # Cache the result self._cached_attrs.add(attr) setattr(self, attr, val) return val 5 user_settings方法 ，通過反射去setting配置文件里找REST_FRAMEWORK屬性，找不到，返回空字典 @property def user_settings(self): if not hasattr(self, '_user_settings'): self._user_settings = getattr(settings, 'REST_FRAMEWORK', {}) return self._user_settings