Django APIView源码解析

from django.views import View
class IndexView(View):
def get(self,request, *args, **kwargs):
return HttpResponse("ok") def dispatch(self, request, *args, **kwargs):
ret = super(IndexView,self).dispatch(request, *args, **kwargs) return HttpResponse(ret)

from rest_framework.views import APIView

url(r"books/$",views.BookView.as_view())

def csrf_exempt(view_func):
def wrapped_view(*args, **kwargs):
return view_func(*args, **kwargs)
wrapped_view.csrf_exempt = True
return wraps(view_func, assigned=available_attrs(view_func))(wrapped_view)

def available_attrs(fn):
if six.PY3:
return WRAPPER_ASSIGNMENTS
else:
return tuple(a for a in WRAPPER_ASSIGNMENTS if hasattr(fn, a))

WRAPPER_ASSIGNMENTS = ('__module__', '__name__', '__qualname__', '__doc__',
'__annotations__')

def wraps(wrapped,
assigned = WRAPPER_ASSIGNMENTS,
updated = WRAPPER_UPDATES):
return partial(update_wrapper, wrapped=wrapped,
assigned=assigned, updated=updated) 

def __new__(*args, **keywords):
if not args:
raise TypeError("descriptor '__new__' of partial needs an argument")
if len(args) < 2:
raise TypeError("type 'partial' takes at least one argument")
cls, func, *args = args
if not callable(func):
raise TypeError("the first argument must be callable")
args = tuple(args) if hasattr(func, "func"):
args = func.args + args
tmpkw = func.keywords.copy()
tmpkw.update(keywords)
keywords = tmpkw
del tmpkw
func = func.func self = super(partial, cls).__new__(cls) self.func = func
self.args = args
self.keywords = keywords
return self def __call__(*args, **keywords):
if not args:
raise TypeError("descriptor '__call__' of partial needs an argument")
self, *args = args
newkeywords = self.keywords.copy()
newkeywords.update(keywords)
return self.func(*self.args, *args, **newkeywords)

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 initialize_request(self, request, *args, **kwargs):
"""
Returns the initial request object.
"""
#将请求变成字典格式返回了
parser_context = self.get_parser_context(request) return Request(
request,
parsers=self.get_parsers(), #解析数据，默认的有三种方式，可点进去看
#self.get_authenticator优先找自己的，没有就找父类的
authenticators=self.get_authenticators(), #获取认证相关的所有类并实例化，传入request对象供Request使用
negotiator=self.get_content_negotiator(),
parser_context=parser_context
)

def get_authenticators(self):
"""
Instantiates and returns the list of authenticators that this view can use.
"""
#返回的是对象列表
return [auth() for auth in self.authentication_classes] #[SessionAuthentication,BaseAuthentication]

authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES #默认的，如果自己有会优先执行自己的

api_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS) #点击继承的DEFAULTS类

DEFAULTS = {
# Base API policies
'DEFAULT_AUTHENTICATION_CLASSES': (
'rest_framework.authentication.SessionAuthentication', #这时候就找到了他默认认证的类了，可以导入看看
'rest_framework.authentication.BasicAuthentication'
),

from rest_framework.authentication import SessionAuthentication
from rest_framework.authentication import BaseAuthentication

class BaseAuthentication(object):
"""
All authentication classes should extend BaseAuthentication.
""" def authenticate(self, request):
"""
Authenticate the request and return a two-tuple of (user, token).
"""
raise NotImplementedError(".authenticate() must be overridden.") def authenticate_header(self, request):
"""
Return a string to be used as the value of the `WWW-Authenticate`
header in a `401 Unauthenticated` response, or `None` if the
authentication scheme should return `403 Permission Denied` responses.
"""
pass

class BasicAuthentication(BaseAuthentication):
"""
HTTP Basic authentication against username/password.
"""
www_authenticate_realm = 'api' def authenticate(self, request):
"""
Returns a `User` if a correct username and password have been supplied
using HTTP Basic authentication. Otherwise returns `None`.
"""
auth = get_authorization_header(request).split() if not auth or auth[0].lower() != b'basic':
return None #返回none不处理。让下一个处理 if len(auth) == 1:
msg = _('Invalid basic header. No credentials provided.')
raise exceptions.AuthenticationFailed(msg)
elif len(auth) > 2:
msg = _('Invalid basic header. Credentials string should not contain spaces.')
raise exceptions.AuthenticationFailed(msg) try:
auth_parts = base64.b64decode(auth[1]).decode(HTTP_HEADER_ENCODING).partition(':') #用partition切割冒号也包括
except (TypeError, UnicodeDecodeError, binascii.Error):
msg = _('Invalid basic header. Credentials not correctly base64 encoded.')
raise exceptions.AuthenticationFailed(msg) userid, password = auth_parts[0], auth_parts[2] # 返回用户和密码
return self.authenticate_credentials(userid, password, request) def authenticate_credentials(self, userid, password, request=None):
"""
Authenticate the userid and password against username and password
with optional request for context.
"""
credentials = {
get_user_model().USERNAME_FIELD: userid,
'password': password
}
user = authenticate(request=request, **credentials) if user is None:
raise exceptions.AuthenticationFailed(_('Invalid username/password.')) if not user.is_active:
raise exceptions.AuthenticationFailed(_('User inactive or deleted.')) return (user, None) def authenticate_header(self, request):
return 'Basic realm="%s"' % self.www_authenticate_realm

def initial(self, request, *args, **kwargs):
"""
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.
#2.1 处理版本信息
version, scheme = self.determine_version(request, *args, **kwargs)
request.version, request.versioning_scheme = version, scheme # Ensure that the incoming request is permitted
#2.2 认证
self.perform_authentication(request)
# 2.3 权限
self.check_permissions(request)
# 2.4 请求用户进行访问频率的限制
self.check_throttles(request)

def perform_authentication(self, request):
"""
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 #执行request的user，这是的request已经是加工后的request了

from rest_framework.views import Request

@property
def user(self):
"""
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 #返回user

def _authenticate(self):
"""
Attempt to authenticate the request using each authentication instance
in turn.
"""
#循环对象列表
for authenticator in self.authenticators:
try:
#执行每一个对象的authenticate 方法
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 #返回一个元组，user，和auth，赋给了self,
# 只要实例化Request，就会有一个request对象，就可以request.user,request.auth了
return self._not_authenticated() 

def _not_authenticated(self):
"""
Set authenticator, user & authtoken representing an unauthenticated request. Defaults are None, AnonymousUser & None.
"""
#如果跳过了所有认证，默认用户和Token和使用配置文件进行设置
self._authenticator = None # if api_settings.UNAUTHENTICATED_USER:
self.user = api_settings.UNAUTHENTICATED_USER() # 默认值为：匿名用户AnonymousUser
else:
self.user = None # None 表示跳过该认证 if api_settings.UNAUTHENTICATED_TOKEN:
self.auth = api_settings.UNAUTHENTICATED_TOKEN() # 默认值为：None
else:
self.auth = None # (user, token)
# 表示验证通过并设置用户名和Token；
# AuthenticationFailed异常

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