先放圖，放圖說話，可能有點長
主流程 這個顏色
從setting導入默認數據流程是 這個顏色
主流程大概流程寫一下：as_view 實際返回view，並把參數{"get":"list","post":"create"}傳遞給view，view會根據傳入的參數設置成 handle=list，get=handle 然後執行dispatch函數，dispatch 先 執行initialize_request（重新封裝request，並調用解析器） 然後執行initial函數（調用版本，認證，頻率，權限組件），通過之後，調用 finalize_response （渲染器，分頁），最後返回結果
發現一片不錯的博文，可以參考https://www.jianshu.com/p/a7fc2f4925d6
# 來個url
url(r'^books/$', views.BookViewSet.as_view({"get":"list","post":"create"}),name="book_list"
######################## viewsets.py ############################
class ViewSetMixin(object):
@classonlymethod
def as_view(cls, actions=None, **initkwargs): # 1、as_view函數，返回view
cls.name = None
cls.description = None
cls.suffix = None
cls.detail = None
cls.basename = None
if not actions:
raise TypeError("The `actions` argument must be provided when "
"calling `.as_view()` on a ViewSet. For example "
"`.as_view({'get': 'list'})`")
# sanitize keyword arguments
for key in initkwargs:
if key in cls.http_method_names:
raise TypeError("You tried to pass in the %s method name as a "
"keyword argument to %s(). Don't do that."
% (key, cls.__name__))
if not hasattr(cls, key):
raise TypeError("%s() received an invalid keyword %r" % (
cls.__name__, key))
# name and suffix are mutually exclusive
if 'name' in initkwargs and 'suffix' in initkwargs:
raise TypeError("%s() received both `name` and `suffix`, which are "
"mutually exclusive arguments." % (cls.__name__))
def view(request, *args, **kwargs): # 2、執行view
self = cls(**initkwargs)
self.action_map = actions # 剛纔傳入的{"get":"list","post":"create"}
for method, action in actions.items(): # 3、設置成 list() = get()
handler = getattr(self, action) # 獲取 list 函數
setattr(self, method, handler) # 爲 get 設置 list
if hasattr(self, 'get') and not hasattr(self, 'head'):
self.head = self.get
self.request = request # 設置request
self.args = args # 保存參數
self.kwargs = kwargs
# And continue as usual
return self.dispatch(request, *args, **kwargs) # 4、dispatch
update_wrapper(view, cls, updated=())
update_wrapper(view, cls.dispatch, assigned=())
view.cls = cls
view.initkwargs = initkwargs
view.actions = actions # {"get":"list","post":"create"} 保存下來，傳入到actions
return csrf_exempt(view) # 返回view
def initialize_request(self, request, *args, **kwargs): # 6、爲requset重新封裝
request = super(ViewSetMixin, self).initialize_request(request, *args, **kwargs) # 調用父類的initialize_request
method = request.method.lower()
if method == 'options':
self.action = 'metadata'
else:
self.action = self.action_map.get(method) # 傳入的{"get":"list","post":"create"}
return request
def reverse_action(self, url_name, *args, **kwargs):
url_name = '%s-%s' % (self.basename, url_name)
kwargs.setdefault('request', self.request)
return reverse(url_name, *args, **kwargs)
@classmethod
def get_extra_actions(cls):
return [method for _, method in getmembers(cls, _is_extra_action)]
def get_extra_action_url_map(self):
action_urls = OrderedDict()
# exit early if `detail` has not been provided
if self.detail is None:
return action_urls
# filter for the relevant extra actions
actions = [
action for action in self.get_extra_actions()
if action.detail == self.detail
]
for action in actions:
try:
url_name = '%s-%s' % (self.basename, action.url_name)
url = reverse(url_name, self.args, self.kwargs, request=self.request)
view = self.__class__(**action.kwargs)
action_urls[view.get_view_name()] = url
except NoReverseMatch:
pass # URL requires additional arguments, ignore
return action_urls
流程2：在setting中找到相應的配置文件
（1）實例化api_settings
api_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS) # DEFAULTS爲默認配置 IMPORT_STRINGS相應模塊
ViewSetMixin 中沒有dispatch ，找父類的，在APIView中找到了
######################## view.py ############################
class APIView(View):
# The following policies may be set at either globally, or per-view.
renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES
parser_classes = api_settings.DEFAULT_PARSER_CLASSES
authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES
throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES
permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES
content_negotiation_class = api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS
metadata_class = api_settings.DEFAULT_METADATA_CLASS
versioning_class = api_settings.DEFAULT_VERSIONING_CLASS # 版本的配置類
# （2）api_settings.* 其實是執行api_settings的__get__ 方法 ，返回相應的類
# Allow dependency injection of other settings to make testing easier.
settings = api_settings
schema = DefaultSchema()
@classmethod
def as_view(cls, **initkwargs):
if isinstance(getattr(cls, 'queryset', None), models.query.QuerySet):
def force_evaluation():
raise RuntimeError(
'Do not evaluate the `.queryset` attribute directly, '
'as the result will be cached and reused between requests. '
'Use `.all()` or call `.get_queryset()` instead.'
)
cls.queryset._fetch_all = force_evaluation
view = super(APIView, cls).as_view(**initkwargs)
view.cls = cls
view.initkwargs = initkwargs
# Note: session based authentication is explicitly CSRF validated,
# all other authentication is CSRF exempt.
return csrf_exempt(view) # 返回View類 中的view
@property
def allowed_methods(self):
"""
Wrap Django's private `_allowed_methods` interface in a public property.
"""
return self._allowed_methods()
@property
def default_response_headers(self):
headers = {
'Allow': ', '.join(self.allowed_methods),
}
if len(self.renderer_classes) > 1:
headers['Vary'] = 'Accept'
return headers
def http_method_not_allowed(self, request, *args, **kwargs):
"""
If `request.method` does not correspond to a handler method,
determine what kind of exception to raise.
"""
raise exceptions.MethodNotAllowed(request.method)
def permission_denied(self, request, message=None):
"""
If request is not permitted, determine what kind of exception to raise.
"""
if request.authenticators and not request.successful_authenticator:
raise exceptions.NotAuthenticated()
raise exceptions.PermissionDenied(detail=message)
def throttled(self, request, wait):
"""
If request is throttled, determine what kind of exception to raise.
"""
raise exceptions.Throttled(wait)
def get_authenticate_header(self, request):
"""
If a request is unauthenticated, determine the WWW-Authenticate
header to use for 401 responses, if any.
"""
authenticators = self.get_authenticators()
if authenticators:
return authenticators[0].authenticate_header(request)
def get_parser_context(self, http_request):
"""
Returns a dict that is passed through to Parser.parse(),
as the `parser_context` keyword argument.
"""
# Note: Additionally `request` and `encoding` will also be added
# to the context by the Request object.
return {
'view': self,
'args': getattr(self, 'args', ()),
'kwargs': getattr(self, 'kwargs', {})
}
def get_renderer_context(self):
"""
Returns a dict that is passed through to Renderer.render(),
as the `renderer_context` keyword argument.
"""
# Note: Additionally 'response' will also be added to the context,
# by the Response object.
return {
'view': self,
'args': getattr(self, 'args', ()),
'kwargs': getattr(self, 'kwargs', {}),
'request': getattr(self, 'request', None)
}
def get_exception_handler_context(self):
"""
Returns a dict that is passed through to EXCEPTION_HANDLER,
as the `context` argument.
"""
return {
'view': self,
'args': getattr(self, 'args', ()),
'kwargs': getattr(self, 'kwargs', {}),
'request': getattr(self, 'request', None)
}
def get_view_name(self):
"""
Return the view name, as used in OPTIONS responses and in the
browsable API.
"""
func = self.settings.VIEW_NAME_FUNCTION
return func(self)
def get_view_description(self, html=False):
"""
Return some descriptive text for the view, as used in OPTIONS responses
and in the browsable API.
"""
func = self.settings.VIEW_DESCRIPTION_FUNCTION
return func(self, html)
# API policy instantiation methods
def get_format_suffix(self, **kwargs):
"""
Determine if the request includes a '.json' style format suffix
"""
if self.settings.FORMAT_SUFFIX_KWARG:
return kwargs.get(self.settings.FORMAT_SUFFIX_KWARG)
def get_renderers(self):
"""
Instantiates and returns the list of renderers that this view can use.
"""
return [renderer() for renderer in self.renderer_classes]
def get_parsers(self):
"""
Instantiates and returns the list of parsers that this view can use.
"""
return [parser() for parser in self.parser_classes]
def get_authenticators(self):
"""
Instantiates and returns the list of authenticators that this view can use.
"""
return [auth() for auth in self.authentication_classes]
def get_permissions(self):
"""
Instantiates and returns the list of permissions that this view requires.
"""
return [permission() for permission in self.permission_classes]
def get_throttles(self):
"""
Instantiates and returns the list of throttles that this view uses.
"""
return [throttle() for throttle in self.throttle_classes]
def get_content_negotiator(self):
"""
Instantiate and return the content negotiation class to use.
"""
if not getattr(self, '_negotiator', None):
self._negotiator = self.content_negotiation_class()
return self._negotiator
def get_exception_handler(self):
"""
Returns the exception handler that this view uses.
"""
return self.settings.EXCEPTION_HANDLER
# API policy implementation methods
def perform_content_negotiation(self, request, force=False):
"""
Determine which renderer and media type to use render the response.
"""
renderers = self.get_renderers()
conneg = self.get_content_negotiator()
try:
return conneg.select_renderer(request, renderers, self.format_kwarg)
except Exception:
if force:
return (renderers[0], renderers[0].media_type)
raise
def perform_authentication(self, request): # 7.2 認證走的函數，實際執行認證類裏的 authenticate(self) 方法
""" # 7.2 認證成功返回（認證之後的用戶，認證的obj），失敗返回（None，None）
Perform authentication on the incoming request.
Note that if you override this and simply 'pass', then authentication
will instead be performed lazily, the first time either
`request.user` or `request.auth` is accessed.
"""
request.user # 傳入request 的 user 方法
def check_permissions(self, request): # 7.3 權限走的函數，實際執行類中的has_permission，有權限返回True，無權限返回False
"""
Check if the request should be permitted.
Raises an appropriate exception if the request is not permitted.
"""
for permission in self.get_permissions():
if not permission.has_permission(request, self):
self.permission_denied(
request, message=getattr(permission, 'message', None)
)
def check_object_permissions(self, request, obj):
"""
Check if the request should be permitted for a given object.
Raises an appropriate exception if the request is not permitted.
"""
for permission in self.get_permissions():
if not permission.has_object_permission(request, self, obj):
self.permission_denied(
request, message=getattr(permission, 'message', None)
)
def check_throttles(self, request): # 頻率走的函數，實際執行類中的allow_request，允許訪問返回True，否則返回False
"""
Check if request should be throttled.
Raises an appropriate exception if the request is throttled.
"""
for throttle in self.get_throttles():
if not throttle.allow_request(request, self):
self.throttled(request, throttle.wait())
def determine_version(self, request, *args, **kwargs): # 7.1 版本走的函數，DRF 提供的版本源碼在 相應的博客中
"""
If versioning is being used, then determine any API version for the
incoming request. Returns a two-tuple of (version, versioning_scheme)
""" # 7.1.1 self.versioning_class 配置了用自己的，沒有配置，用默認的
if self.versioning_class is None: # 7.1.2 版本類爲空，返回none，否則調用版本的determine_version方法，返回獲取到的版本version
return (None, None)
scheme = self.versioning_class()
return (scheme.determine_version(request, *args, **kwargs), scheme) # 7.1.3 返回版本信息和版本類
# Dispatch methods
def initialize_request(self, request, *args, **kwargs): # 6、爲requset重新封裝
parser_context = self.get_parser_context(request)
return Request(
request,
parsers=self.get_parsers(), # 6 解析器再此
authenticators=self.get_authenticators(),
negotiator=self.get_content_negotiator(),
parser_context=parser_context
)
def initial(self, request, *args, **kwargs): # 7、版本、頻率、認證、權限 等
"""
Runs anything that needs to occur prior to calling the method handler.
"""
self.format_kwarg = self.get_format_suffix(**kwargs)
# Perform content negotiation and store the accepted info on the request
neg = self.perform_content_negotiation(request)
request.accepted_renderer, request.accepted_media_type = neg
# Determine the API version, if versioning is in use.
version, scheme = self.determine_version(request, *args, **kwargs) # 7.1 獲取版本信息，返回值 版本信息，版本類
request.version, request.versioning_scheme = version, scheme # 版本信息，版本類
# Ensure that the incoming request is permitted
self.perform_authentication(request) # 7.2 認證
self.check_permissions(request) # 7.3 權限
self.check_throttles(request) # 7.4 頻率
def finalize_response(self, request, response, *args, **kwargs): # 10、返回前的最後一步，
"""
Returns the final response object.
"""
# Make the error obvious if a proper response is not returned
assert isinstance(response, HttpResponseBase), (
'Expected a `Response`, `HttpResponse` or `HttpStreamingResponse` '
'to be returned from the view, but received a `%s`'
% type(response)
)
if isinstance(response, Response):
if not getattr(request, 'accepted_renderer', None):
neg = self.perform_content_negotiation(request, force=True)
request.accepted_renderer, request.accepted_media_type = neg
response.accepted_renderer = request.accepted_renderer # 渲染器
response.accepted_media_type = request.accepted_media_type
response.renderer_context = self.get_renderer_context()
# Add new vary headers to the response instead of overwriting.
vary_headers = self.headers.pop('Vary', None)
if vary_headers is not None:
patch_vary_headers(response, cc_delim_re.split(vary_headers))
for key, value in self.headers.items():
response[key] = value
return response
def handle_exception(self, exc):
"""
Handle any exception that occurs, by returning an appropriate response,
or re-raising the error.
"""
if isinstance(exc, (exceptions.NotAuthenticated,
exceptions.AuthenticationFailed)):
# WWW-Authenticate header for 401 responses, else coerce to 403
auth_header = self.get_authenticate_header(self.request)
if auth_header:
exc.auth_header = auth_header
else:
exc.status_code = status.HTTP_403_FORBIDDEN
exception_handler = self.get_exception_handler()
context = self.get_exception_handler_context()
response = exception_handler(exc, context)
if response is None:
self.raise_uncaught_exception(exc)
response.exception = True
return response
def raise_uncaught_exception(self, exc):
if settings.DEBUG:
request = self.request
renderer_format = getattr(request.accepted_renderer, 'format')
use_plaintext_traceback = renderer_format not in ('html', 'api', 'admin')
request.force_plaintext_errors(use_plaintext_traceback)
raise
# Note: Views are made CSRF exempt from within `as_view` as to prevent
# accidental removal of this exemption in cases where `dispatch` needs to
# be overridden.
def dispatch(self, request, *args, **kwargs): # 5、執行dispatch
self.args = args
self.kwargs = kwargs
request = self.initialize_request(request, *args, **kwargs) # 6、爲requset重新封裝，其中有解析器
self.request = request # 重新賦值
self.headers = self.default_response_headers # deprecate?
try:
self.initial(request, *args, **kwargs) # 7、版本、頻率、認證、權限 等
# 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) # 8、找個 'get' 函數
else:
handler = self.http_method_not_allowed
response = handler(request, *args, **kwargs) # 9、執行 'get' 函數
except Exception as exc:
response = self.handle_exception(exc)
self.response = self.finalize_response(request, response, *args, **kwargs) # 10、返回前的最後一步
return self.response
def options(self, request, *args, **kwargs):
"""
Handler method for HTTP 'OPTIONS' request.
"""
if self.metadata_class is None:
return self.http_method_not_allowed(request, *args, **kwargs)
data = self.metadata_class().determine_metadata(request, self)
return Response(data, status=status.HTTP_200_OK)
附 view 源碼
###################### base.py ###############
class View(object):
http_method_names = ['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']
def __init__(self, **kwargs):
"""
Constructor. Called in the URLconf; can contain helpful extra
keyword arguments, and other things.
"""
# Go through keyword arguments, and either save their values to our
# instance, or raise an error.
for key, value in six.iteritems(kwargs):
setattr(self, key, value)
@classonlymethod
def as_view(cls, **initkwargs):
"""
Main entry point for a request-response process.
"""
for key in initkwargs:
if key in cls.http_method_names:
raise TypeError("You tried to pass in the %s method name as a "
"keyword argument to %s(). Don't do that."
% (key, cls.__name__))
if not hasattr(cls, key):
raise TypeError("%s() received an invalid keyword %r. as_view "
"only accepts arguments that are already "
"attributes of the class." % (cls.__name__, key))
def view(request, *args, **kwargs):
self = cls(**initkwargs)
if hasattr(self, 'get') and not hasattr(self, 'head'):
self.head = self.get
self.request = request
self.args = args
self.kwargs = kwargs
return self.dispatch(request, *args, **kwargs)
view.view_class = cls
view.view_initkwargs = initkwargs
# take name and docstring from class
update_wrapper(view, cls, updated=())
# and possible attributes set by decorators
# like csrf_exempt from dispatch
update_wrapper(view, cls.dispatch, assigned=())
return view
def dispatch(self, request, *args, **kwargs):
# Try to dispatch to the right method; if a method doesn't exist,
# defer to the error handler. Also defer to the error handler if the
# request method isn't on the approved list.
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
return handler(request, *args, **kwargs)
def http_method_not_allowed(self, request, *args, **kwargs):
logger.warning(
'Method Not Allowed (%s): %s', request.method, request.path,
extra={'status_code': 405, 'request': request}
)
return http.HttpResponseNotAllowed(self._allowed_methods())
def options(self, request, *args, **kwargs):
"""
Handles responding to requests for the OPTIONS HTTP verb.
"""
response = http.HttpResponse()
response['Allow'] = ', '.join(self._allowed_methods())
response['Content-Length'] = '0'
return response
def _allowed_methods(self):
return [m.upper() for m in self.http_method_names if hasattr(self, m)]
獲取配置信息APISettings的源碼
############################# setting.py ############################
class APISettings(object):
def __init__(self, user_settings=None, defaults=None, import_strings=None):
if user_settings:
self._user_settings = self.__check_user_settings(user_settings)
self.defaults = defaults or DEFAULTS （1）實例化調用的__init__
self.import_strings = import_strings or IMPORT_STRINGS
self._cached_attrs = set()
@property
def user_settings(self):
if not hasattr(self, '_user_settings'):
self._user_settings = getattr(settings, 'REST_FRAMEWORK', {})
return self._user_settings
def __getattr__(self, attr): # （2）調用getattr方法
if attr not in self.defaults: # （3）如果名字不在默認中存在，報錯
raise AttributeError("Invalid API setting: '%s'" % attr)
try: # （4）在Django的setting中有就用，沒有用默認配置中的配置
# Check if present in user settings
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: # （5）導入相應的模塊
val = perform_import(val, attr)
# Cache the result
self._cached_attrs.add(attr)
setattr(self, attr, val) # （6）將模塊賦值給attr，並返回
return val
def __check_user_settings(self, user_settings):
SETTINGS_DOC = "https://www.django-rest-framework.org/api-guide/settings/"
for setting in REMOVED_SETTINGS:
if setting in user_settings:
raise RuntimeError("The '%s' setting has been removed. Please refer to '%s' for available settings." % (setting, SETTINGS_DOC))
return user_settings
def reload(self):
for attr in self._cached_attrs:
delattr(self, attr)
self._cached_attrs.clear()
if hasattr(self, '_user_settings'):
delattr(self, '_user_settings')
下面這個是再導入diango的配置 from django.conf import settings
################################ setting.py ############################################
# 內容有點長，作用是導入Django的settings
def reload_api_settings(*args, **kwargs):
setting = kwargs['setting']
if setting == 'REST_FRAMEWORK':
api_settings.reload()
setting_changed.connect(reload_api_settings)
request的源碼
################################ request.py ############################################
class Request(object):
"""
Wrapper allowing to enhance a standard `HttpRequest` instance.
Kwargs:
- request(HttpRequest). The original request instance.
- parsers_classes(list/tuple). The parsers to use for parsing the
request content.
- authentication_classes(list/tuple). The authentications used to try
authenticating the request's user.
"""
def __init__(self, request, parsers=None, authenticators=None,
negotiator=None, parser_context=None):
assert isinstance(request, HttpRequest), (
'The `request` argument must be an instance of '
'`django.http.HttpRequest`, not `{}.{}`.'
.format(request.__class__.__module__, request.__class__.__name__)
)
self._request = request
self.parsers = parsers or ()
self.authenticators = authenticators or ()
self.negotiator = negotiator or self._default_negotiator()
self.parser_context = parser_context
self._data = Empty
self._files = Empty
self._full_data = Empty
self._content_type = Empty
self._stream = Empty
if self.parser_context is None:
self.parser_context = {}
self.parser_context['request'] = self
self.parser_context['encoding'] = request.encoding or settings.DEFAULT_CHARSET
force_user = getattr(request, '_force_auth_user', None)
force_token = getattr(request, '_force_auth_token', None)
if force_user is not None or force_token is not None:
forced_auth = ForcedAuthentication(force_user, force_token)
self.authenticators = (forced_auth,)
def _default_negotiator(self):
return api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS()
@property
def content_type(self):
meta = self._request.META
return meta.get('CONTENT_TYPE', meta.get('HTTP_CONTENT_TYPE', ''))
@property
def stream(self):
"""
Returns an object that may be used to stream the request content.
"""
if not _hasattr(self, '_stream'):
self._load_stream()
return self._stream
@property
def query_params(self):
"""
More semantically correct name for request.GET.
"""
return self._request.GET
@property
def data(self):
if not _hasattr(self, '_full_data'):
self._load_data_and_files()
return self._full_data
@property
def user(self): # 7.2 認證的走到這，實際執行 self._authenticate()，
"""
Returns the user associated with the current request, as authenticated
by the authentication classes provided to the request.
"""
if not hasattr(self, '_user'):
with wrap_attributeerrors():
self._authenticate()
return self._user
@user.setter
def user(self, value):
"""
Sets the user on the current request. This is necessary to maintain
compatibility with django.contrib.auth where the user property is
set in the login and logout functions.
Note that we also set the user on Django's underlying `HttpRequest`
instance, ensuring that it is available to any middleware in the stack.
"""
self._user = value
self._request.user = value
@property
def auth(self):
"""
Returns any non-user authentication information associated with the
request, such as an authentication token.
"""
if not hasattr(self, '_auth'):
with wrap_attributeerrors():
self._authenticate()
return self._auth
@auth.setter
def auth(self, value):
"""
Sets any non-user authentication information associated with the
request, such as an authentication token.
"""
self._auth = value
self._request.auth = value
@property
def successful_authenticator(self):
"""
Return the instance of the authentication instance class that was used
to authenticate the request, or `None`.
"""
if not hasattr(self, '_authenticator'):
with wrap_attributeerrors():
self._authenticate()
return self._authenticator
def _load_data_and_files(self):
"""
Parses the request content into `self.data`.
"""
if not _hasattr(self, '_data'):
self._data, self._files = self._parse()
if self._files:
self._full_data = self._data.copy()
self._full_data.update(self._files)
else:
self._full_data = self._data
# if a form media type, copy data & files refs to the underlying
# http request so that closable objects are handled appropriately.
if is_form_media_type(self.content_type):
self._request._post = self.POST
self._request._files = self.FILES
def _load_stream(self):
"""
Return the content body of the request, as a stream.
"""
meta = self._request.META
try:
content_length = int(
meta.get('CONTENT_LENGTH', meta.get('HTTP_CONTENT_LENGTH', 0))
)
except (ValueError, TypeError):
content_length = 0
if content_length == 0:
self._stream = None
elif not self._request._read_started:
self._stream = self._request
else:
self._stream = io.BytesIO(self.body)
def _supports_form_parsing(self):
"""
Return True if this requests supports parsing form data.
"""
form_media = (
'application/x-www-form-urlencoded',
'multipart/form-data'
)
return any([parser.media_type in form_media for parser in self.parsers])
def _parse(self):
"""
Parse the request content, returning a two-tuple of (data, files)
May raise an `UnsupportedMediaType`, or `ParseError` exception.
"""
media_type = self.content_type
try:
stream = self.stream
except RawPostDataException:
if not hasattr(self._request, '_post'):
raise
# If request.POST has been accessed in middleware, and a method='POST'
# request was made with 'multipart/form-data', then the request stream
# will already have been exhausted.
if self._supports_form_parsing():
return (self._request.POST, self._request.FILES)
stream = None
if stream is None or media_type is None:
if media_type and is_form_media_type(media_type):
empty_data = QueryDict('', encoding=self._request._encoding)
else:
empty_data = {}
empty_files = MultiValueDict()
return (empty_data, empty_files)
parser = self.negotiator.select_parser(self, self.parsers)
if not parser:
raise exceptions.UnsupportedMediaType(media_type)
try:
parsed = parser.parse(stream, media_type, self.parser_context)
except Exception:
# If we get an exception during parsing, fill in empty data and
# re-raise. Ensures we don't simply repeat the error when
# attempting to render the browsable renderer response, or when
# logging the request or similar.
self._data = QueryDict('', encoding=self._request._encoding)
self._files = MultiValueDict()
self._full_data = self._data
raise
# Parser classes may return the raw data, or a
# DataAndFiles object. Unpack the result as required.
try:
return (parsed.data, parsed.files)
except AttributeError:
empty_files = MultiValueDict()
return (parsed, empty_files)
def _authenticate(self): # 7.2 認證時真正執行的地方
"""
Attempt to authenticate the request using each authentication instance
in turn.
"""
for authenticator in self.authenticators: # 7.2 查找當前配置的self.authenticators，執行裏面的authenticate(self)
try: # 7.2 最後返回一個元祖，（認證之後的用戶，認證的obj）
user_auth_tuple = authenticator.authenticate(self)
except exceptions.APIException:
self._not_authenticated()
raise
if user_auth_tuple is not None:
self._authenticator = authenticator
self.user, self.auth = user_auth_tuple
return
self._not_authenticated()
def _not_authenticated(self): # 7.2 如果沒有認證，那麼返回（None，None）
"""
Set authenticator, user & authtoken representing an unauthenticated request.
Defaults are None, AnonymousUser & None.
"""
self._authenticator = None
if api_settings.UNAUTHENTICATED_USER:
self.user = api_settings.UNAUTHENTICATED_USER()
else:
self.user = None
if api_settings.UNAUTHENTICATED_TOKEN:
self.auth = api_settings.UNAUTHENTICATED_TOKEN()
else:
self.auth = None
def __getattr__(self, attr):
"""
If an attribute does not exist on this instance, then we also attempt
to proxy it to the underlying HttpRequest object.
"""
try:
return getattr(self._request, attr)
except AttributeError:
return self.__getattribute__(attr)
@property
def DATA(self):
raise NotImplementedError(
'`request.DATA` has been deprecated in favor of `request.data` '
'since version 3.0, and has been fully removed as of version 3.2.'
)
@property
def POST(self):
# Ensure that request.POST uses our request parsing.
if not _hasattr(self, '_data'):
self._load_data_and_files()
if is_form_media_type(self.content_type):
return self._data
return QueryDict('', encoding=self._request._encoding)
@property
def FILES(self):
# Leave this one alone for backwards compat with Django's request.FILES
# Different from the other two cases, which are not valid property
# names on the WSGIRequest class.
if not _hasattr(self, '_files'):
self._load_data_and_files()
return self._files
@property
def QUERY_PARAMS(self):
raise NotImplementedError(
'`request.QUERY_PARAMS` has been deprecated in favor of `request.query_params` '
'since version 3.0, and has been fully removed as of version 3.2.'
)
def force_plaintext_errors(self, value):
# Hack to allow our exception handler to force choice of
# plaintext or html error responses.
self._request.is_ajax = lambda: value