restful(表者征状态转移，面向资源编程)------------------------------------------->约定
从资源的角度审视整个网络，将分布在网络中某个节点的资源通过url进行标识，客户端通过url获取资源的表征，
获得这些表征使应用转变状态。-----------------------------------------------------------是一种软件架构风格。
所有数据是通过网络获取的是操作的数据(增删改查)，都是资源-------------------------------互联网上的一切东西都视为资源。
restf规则：
API与用户的通信协议，使用的是http协议
1：域名尽量部署在专有域名之下，若API很简单，不会进一步扩展,可以考虑放在主域名下。
2：应将api的版本号放入url,还可以将版本号放入Http请求头信息中，但不如放在url中方便。
3：在RESTful架构中，每个网址代表一种资源（resource），所以网址中应该有动词，应该使用名词，
而且所用的名词往往与数据库的表格名对应。一般来说，数据库中的表都是同种记录的"集合"（collection），所以API中的名词也应该使用复数。
4：用于区别url接口应将API加入到url.
5: 如果记录数量很多，服务器不可能都将它们返回给用户。API应该提供参数，过滤返回结果。
6: 服务器向用户返回的状态码和提示信息。
8: 如果状态码是4xx，就应该向用户返回出错信息。一般来说，返回的信息中将error作为键名，出错信息作为键值即可。
9: 请求方式的不同，进行不同的操作。post----get----put----patch----delete
10：返回错误信息
restful-api:
API与用户的通行协议，总是使用HTTPs协议
api:---------------------------------------------------------------------------------------接口
用途：
1：为别人提供服务----------发送短信
2：前后端分离--------------前后端分离
规范：
1:url+api
https://api.example.com------------------------------------------------------------尽量将API部署在专用域名（会存在跨域问题)
https://example.org/api/-----------------------------------------------------------API很简单
2:名词
资源名必须是名词，不能是动词.......
3:版本
URL，-------------------------------------------------------------------------------如：https://api.example.com/v1/
请求头------------------------------------------------------------------------------跨域时，引发发送多次请求
4:提交方式------------------------------------------------------------method
GET：-------------------------------------------------------------------------------从服务器取出资源（一项或多项）
POST：------------------------------------------------------------------------------在服务器新建一个资源
PUT：-------------------------------------------------------------------------------在服务器更新资源（客户端提供改变后的完整资源）
PATCH ：----------------------------------------------------------------------------在服务器更新资源（客户端提供改变的属性）
DELETE：----------------------------------------------------------------------------从服务器删除资源
5:json数据------------------------------------------------------------返回json数据
6:status--------------------------------------------------------------状态码
200 OK - [GET]：服务器成功返回用户请求的数据，该操作是幂等的（Idempotent）。
201 CREATED - [POST/PUT/PATCH]：用户新建或修改数据成功。
202 Accepted - [*]：表示一个请求已经进入后台排队（异步任务）
204 NO CONTENT - [DELETE]：用户删除数据成功。
400 INVALID REQUEST - [POST/PUT/PATCH]：用户发出的请求有错误，服务器没有进行新建或修改数据的操作，该操作是幂等的。
401 Unauthorized - [*]：表示用户没有权限（令牌、用户名、密码错误）。
403 Forbidden - [*] 表示用户得到授权（与401错误相对），但是访问是被禁止的。
404 NOT FOUND - [*]：用户发出的请求针对的是不存在的记录，服务器没有进行操作，该操作是幂等的。
406 Not Acceptable - [GET]：用户请求的格式不可得（比如用户请求JSON格式，但是只有XML格式）。
410 Gone -[GET]：用户请求的资源被永久删除，且不会再得到的。
422 Unprocesable entity - [POST/PUT/PATCH] 当创建一个对象时，发生一个验证错误。
500 INTERNAL SERVER ERROR - [*]：服务器发生错误，用户将无法判断发出的请求是否成功。
更多看这里：http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
7:aypermedia link-----------------------------------------------------返回链接
Hypermedia API，RESTful API最好做到Hypermedia，即返回结果中提供链接，连向其他API方法，使得用户不查文档，也知道下一步应该做什么。
{"link": {
"rel": "collection https://www.example.com/zoos",
"href": "https://api.example.com/zoos",
"title": "List of zoos",
"type": "application/vnd.yourformat+json"
}}
8:错误处理
错误处理，状态码是4xx时，应返回错误信息，error当做key。
{
error: "Invalid API key"
}
为什么做前后端分离？
数据的解耦，提高开发效率。
安装：
pip3 install djangorestframework -i http://pypi.douban.com/simple/ --trusted-host=pypi.douban.com
继承关系：
class View(object):-------------------------------------------------view
class APIView(View):------------------------------------------------APIview
class GenericAPIView(views.APIView):--------------------------------GenericAPIView
class GenericViewSet(ViewSetMixin, generics.GenericAPIView)---------GenericViewSet
class ModelViewSet(mixins.CreateModelMixin,-------------------------ModelViewSet(增删改查，genericViewset)
mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
mixins.ListModelMixin,
GenericViewSet):
Django Rest Framework 的的请求生命周期：
hTTP请求 —> wsgi —> 中间件 —> 路由分发 —> 执行对应类的dispatch方法 —> 视图函数 —>返回
采用CBV的请求方式。
源码剖析
接收HTTP请求---->wsgi----->中间件------->路由分发---------->执行对应类的dispatch方法------->视图函数------>返回
首先执行 as_view 我们可以知道，as_view调用了dispatch.
执行：------------------------>执行对应类的dispatch方法：---------------------dispatch
一：第一步对------------------------------------------------------------------request二次封装
1：--查看initialize_request方法,可以知道这个方法接收客户端的request请求,再重新封装成新的request。
def initialize_request(self, request, *args, **kwargs):
parser_context = self.get_parser_context(request)
return Request(
request,
parsers=self.get_parsers(),
authenticators=self.get_authenticators(),
negotiator=self.get_content_negotiator(),
parser_context=parser_context
)
点击进入Request
2:----再查看Request方法的源码，可以知道这个Request类是rest framework中定义的一个类
----Rquest类,这来类是经过Request处理过的request已经不再是客户端发送过来的那个request了
class Request(object):
def __init__(self, request, parsers=None, authenticators=None,
negotiator=None, parser_context=None):
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,)
3:----在initialize_request方法中,有一个方法处理过request,来看看get_parser_context方法的源码
在这里,view的值是self,代指的是UsersView这个对象,所以get_parser_context方法把UsersView这个类封装进来然后返回
所以get_parser_context方法最后返回的当前对象以及当前对象所传的参数，经过initialize_request函数处理之后的request,现在就变成了
Request(
request,
parsers=self.get_parsers(),
authenticators=self.get_authenticators(),
negotiator=self.get_content_negotiator(),
parser_context=parser_context
)
def get_parser_context(self, http_request):
return {
'view': self, #代指的是UsersView这个对象
'args': getattr(self, 'args', ()),
'kwargs': getattr(self, 'kwargs', {})
}
4:----现在再来看看Request的其他参数代指的是什么
get_parsers------------------根据字面意思,是解析get请求的意思
def get_parsers(self):
return [parser() for parser in self.parser_classes]
get_content_negotiator-------选择相关
def get_content_negotiator(self):
if not getattr(self, '_negotiator', None):
self._negotiator = self.content_negotiation_class()
return self._negotiator
parser_context---------------封闭self和self的参数
parser_context = self.get_parser_context(request)
*get_authenticators----------------------认证相关,在get_authenticators这个方法中循环了self.authentication_classes返回了一个列表对象，
def get_authenticators(self):
return [auth() for auth in self.authentication_classes]
----------他是self.找的，所有它先去我们写的那个类中去找authentication_classes，我们写的类中没有才去父类中找，因此我们就可以自定义这个列表类了。
进入APIview类找------------------authentication_classes
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 #认证
throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES #权限
permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES #分流
content_negotiation_class = api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS
metadata_class = api_settings.DEFAULT_METADATA_CLASS
versioning_class = api_settings.DEFAULT_VERSIONING_CLASS
..............
------------authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES由此可以看出:
它默认的authentication_classes是从它的配置文件中读出来的。现在就可以去看看它配置文件中的类了。
-------------进入api_settings可以看到api_settings=APISettings
api_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS)
-----------进入APISettings，默认的authentication_classes是从它的配置文件中读出来的。现在就可以去看看它配置文件中的类了
DEFAULTS = {
# Base API policies
'DEFAULT_RENDERER_CLASSES': (
'rest_framework.renderers.JSONRenderer',
'rest_framework.renderers.BrowsableAPIRenderer',
),
'DEFAULT_PARSER_CLASSES': (
'rest_framework.parsers.JSONParser',
'rest_framework.parsers.FormParser',
'rest_framework.parsers.MultiPartParser'
),
'DEFAULT_AUTHENTICATION_CLASSES': (
'rest_framework.authentication.SessionAuthentication',
'rest_framework.authentication.BasicAuthentication'
),
'DEFAULT_PERMISSION_CLASSES': (
'rest_framework.permissions.AllowAny',
),
'DEFAULT_THROTTLE_CLASSES': (),
'DEFAULT_CONTENT_NEGOTIATION_CLASS': 'rest_framework.negotiation.DefaultContentNegotiation',
'DEFAULT_METADATA_CLASS': 'rest_framework.metadata.SimpleMetadata',
'DEFAULT_VERSIONING_CLASS': None,
# Generic view behavior
'DEFAULT_PAGINATION_CLASS': None,
'DEFAULT_FILTER_BACKENDS': (),
# Schema
'DEFAULT_SCHEMA_CLASS': 'rest_framework.schemas.AutoSchema',
# Throttling
'DEFAULT_THROTTLE_RATES': {
'user': None,
'anon': None,
},
'NUM_PROXIES': None,
# Pagination
'PAGE_SIZE': None,
# Filtering
'SEARCH_PARAM': 'search',
'ORDERING_PARAM': 'ordering',
# Versioning
'DEFAULT_VERSION': None,
'ALLOWED_VERSIONS': None,
'VERSION_PARAM': 'version',
# Authentication
'UNAUTHENTICATED_USER': 'django.contrib.auth.models.AnonymousUser',
'UNAUTHENTICATED_TOKEN': None,
# View configuration
'VIEW_NAME_FUNCTION': 'rest_framework.views.get_view_name',
'VIEW_DESCRIPTION_FUNCTION': 'rest_framework.views.get_view_description',
# Exception handling
'EXCEPTION_HANDLER': 'rest_framework.views.exception_handler',
'NON_FIELD_ERRORS_KEY': 'non_field_errors',
# Testing
'TEST_REQUEST_RENDERER_CLASSES': (
'rest_framework.renderers.MultiPartRenderer',
'rest_framework.renderers.JSONRenderer'
),
'TEST_REQUEST_DEFAULT_FORMAT': 'multipart',
# Hyperlink settings
'URL_FORMAT_OVERRIDE': 'format',
'FORMAT_SUFFIX_KWARG': 'format',
'URL_FIELD_NAME': 'url',
# Input and output formats
'DATE_FORMAT': ISO_8601,
'DATE_INPUT_FORMATS': (ISO_8601,),
'DATETIME_FORMAT': ISO_8601,
'DATETIME_INPUT_FORMATS': (ISO_8601,),
'TIME_FORMAT': ISO_8601,
'TIME_INPUT_FORMATS': (ISO_8601,),
# Encoding
'UNICODE_JSON': True,
'COMPACT_JSON': True,
'STRICT_JSON': True,
'COERCE_DECIMAL_TO_STRING': True,
'UPLOADED_FILES_USE_URL': True,
# Browseable API
'HTML_SELECT_CUTOFF': 1000,
'HTML_SELECT_CUTOFF_TEXT': "More than {count} items...",
# Schemas
'SCHEMA_COERCE_PATH_PK': True,
'SCHEMA_COERCE_METHOD_NAMES': {
'retrieve': 'read',
'destroy': 'delete'
},
}
-----------找到DEFAULT_AUTHENTICATION_CLASSES可以看出他有两个类是在authentication中：SessionAuthentication，BasicAuthentication，
'DEFAULT_AUTHENTICATION_CLASSES': (
'rest_framework.authentication.SessionAuthentication',
'rest_framework.authentication.BasicAuthentication'
),
--------------from rest_framework import authentication进入
--------------SessionAuthentication
class SessionAuthentication(BaseAuthentication):
"""
Use Django's session framework for authentication.
"""
def authenticate(self, request):
"""
Returns a `User` if the request session currently has a logged in user.
Otherwise returns `None`.
"""
# Get the session-based user from the underlying HttpRequest object
user = getattr(request._request, 'user', None)
# Unauthenticated, CSRF validation not required
if not user or not user.is_active:
return None
self.enforce_csrf(request)
# CSRF passed with authenticated user
return (user, None)
def enforce_csrf(self, request):
"""
Enforce CSRF validation for session based authentication.
"""
reason = CSRFCheck().process_view(request, None, (), {})
if reason:
# CSRF failed, bail with explicit error message
raise exceptions.PermissionDenied('CSRF Failed: %s' % reason)
--------------BasicAuthentication
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
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(':')
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]
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
--------------可以看出他们都继承了一个BaseAuthentication的类并且都实现了authenticate方法。
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
--------------进入authenticate，由此可以看出BaseAuthentication类其实是一个接口类，让继承它的类必须实现authenticate方法。
最后就是在request对象中的authenticatotes中封装了一些关于认证的对。
def authenticate(self, request):
"""
Authenticate the request and return a two-tuple of (user, token).
"""
raise NotImplementedError(".authenticate() must be overridden.")
-----------自己添加配置文件-------settings:若将自己定义的认证类添加的返回的列表，就通过seettings的配置走自己的定义的认证类
EST_FRAMEWORK = {
'UNAUTHENTICATED_USER': None,
'UNAUTHENTICATED_TOKEN': None,
"DEFAULT_AUTHENTICATION_CLASSES": [
# "app01.utils.MyAuthentication",
],
'DEFAULT_PERMISSION_CLASSES':[
],
'DEFAULT_THROTTLE_RATES':{
'wdp_anon':'5/minute',
'wdp_user':'10/minute',
}
}
5:---再来看看UsersView这个类中的get方法和post方法----------------------------------------------------------------UserView
可以看到get方法的参数中有一个request,通过前面可以知道这个request已经不是最开始时到达服务端的request了
这个request方法中已经被REST framework封装了解析,认证和选择等相关的方法
def get(self,request,*args,**kwargs):
pass
def post(self,request,*args,**kwargs):
pass
6：---efault_response_headers这个方法从它的注释可以看出已经被丢弃了.
二：初始化--------------------------------------------------------------------获取版本-----认证-----权限-----分流
7：---再来看initial这个方法
def initial(self, request, *args, **kwargs):
self.format_kwarg = self.get_format_suffix(**kwargs)
# Perform content negotiation and store the accepted info on the request
#执行内容协商并将接受的信息存储在请求上
neg = self.perform_content_negotiation(request)
request.accepted_renderer, request.accepted_media_type = neg
# Determine the API version, if versioning is in use.
#如果正在使用版本控制，请确定API版本。
version, scheme = self.determine_version(request, *args, **kwargs)
request.version, request.versioning_scheme = version, scheme
# Ensure that the incoming request is permitted
#确保传入的请求是允许的。
self.perform_authentication(request)
self.check_permissions(request)
self.check_throttles(request)
----先执行get_format_suffix-------------------------------------------------------------来获取客户端所发送的url的后缀
----然后执行perform_content_negotiation方法,--------------------------------------------这个方法的主要作用是执行内容选择,并把服务端接收到的信息保存在request中
获取版本----然后再执行determine_version方法---------------------------------------------如果url中有版本信息,就获取发送到服务端的版本,返回一个元组
-------version,schemas是执行determine_version获得的，versioning_scheme是设置类的对象也就是QueryParameterVersioning。
request.version就是QueryParameterVersioning执行etermine_version
version, scheme = self.determine_version(request, *args, **kwargs)
request.version, request.versioning_scheme = version, scheme
--------执行determine_version，如果versioning是空的，就返回两个空。，不为空走versioning设置值。
def determine_version(self, request, *args, **kwargs):
if self.versioning_class is None:
return (None, None)
scheme = self.versioning_class()
return (scheme.determine_version(request, *args, **kwargs), scheme)
---------走versiong_class设置值，走api_settings配置找DEFAULT_VERSIONING_CLASS
versioning_class = api_settings.DEFAULT_VERSIONING_CLASS
----------走api_settings寻找配置
api_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS)
---------api_settings = APISettings，走APISettings找DEFAULT_VERSIONING_CLASS。默认为空，需自己设置。
'DEFAULT_VERSIONING_CLASS': None,
---------进入QueryParameterVersioning
class QueryParameterVersioning(BaseVersioning):
"""
GET /something/?version=0.1 HTTP/1.1
Host: example.com
Accept: application/json
"""
invalid_version_message = _('Invalid version in query parameter.')
def determine_version(self, request, *args, **kwargs):
version = request.query_params.get(self.version_param, self.default_version)
if not self.is_allowed_version(version):
raise exceptions.NotFound(self.invalid_version_message)
return version
def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):
url = super(QueryParameterVersioning, self).reverse(
viewname, args, kwargs, request, format, **extra
)
if request.version is not None:
return replace_query_param(url, self.version_param, request.version)
return url
---------获取version,version_param就是配置
def determine_version(self, request, *args, **kwargs):
version = request.query_params.get(self.version_param, self.default_version)
if not self.is_allowed_version(version):
raise exceptions.NotFound(self.invalid_version_message)
return version
---------进入version_param，在配置中找VERSION_PARAM
version_param = api_settings.VERSION_PARAM
---------由配置可知VERSION_PARAM等于version.
'VERSION_PARAM': 'version',
---------default_version=配置中的DEFAULT_VERSION
default_version = api_settings.DEFAULT_VERSION
---------进入配置找DEFAULT_VERSION，可以知道我们可以在setting中自己配置
---------is_allowed_version是允许的版本，也可自己在seettings中配置。流程相似
-------from rest_framework.versioning import QueryParameterVersioning,URLPathVersioning
---------QueryParameterVersioning
class QueryParameterVersioning(BaseVersioning):
"""
GET /something/?version=0.1 HTTP/1.1
Host: example.com
Accept: application/json
"""
invalid_version_message = _('Invalid version in query parameter.')
def determine_version(self, request, *args, **kwargs):
version = request.query_params.get(self.version_param, self.default_version)
if not self.is_allowed_version(version):
raise exceptions.NotFound(self.invalid_version_message)
return version
def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):
url = super(QueryParameterVersioning, self).reverse(
viewname, args, kwargs, request, format, **extra
)
if request.version is not None:
return replace_query_param(url, self.version_param, request.version)
return url
--------执行determine_version获取版本
def determine_version(self, request, *args, **kwargs):
version = request.query_params.get(self.version_param, self.default_version)
if not self.is_allowed_version(version):
raise exceptions.NotFound(self.invalid_version_message)
return version
--------执行reverse反向生成url
def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):
url = super(QueryParameterVersioning, self).reverse(
viewname, args, kwargs, request, format, **extra
)
if request.version is not None:
return replace_query_param(url, self.version_param, request.version)
return url
---------URLPathVersioning
class URLPathVersioning(BaseVersioning):
"""
To the client this is the same style as `NamespaceVersioning`.
The difference is in the backend - this implementation uses
Django's URL keyword arguments to determine the version.
An example URL conf for two views that accept two different versions.
urlpatterns = [
url(r'^(?P<version>[v1|v2]+)/users/$', users_list, name='users-list'),
url(r'^(?P<version>[v1|v2]+)/users/(?P<pk>[0-9]+)/$', users_detail, name='users-detail')
]
GET /1.0/something/ HTTP/1.1
Host: example.com
Accept: application/json
"""
invalid_version_message = _('Invalid version in URL path.')
def determine_version(self, request, *args, **kwargs):
version = kwargs.get(self.version_param, self.default_version)
if not self.is_allowed_version(version):
raise exceptions.NotFound(self.invalid_version_message)
return version
def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):
if request.version is not None:
kwargs = {} if (kwargs is None) else kwargs
kwargs[self.version_param] = request.version
return super(URLPathVersioning, self).reverse(
viewname, args, kwargs, request, format, **extra
)
---------自己在settings中配置
REST_FRAMEWORK = {
'VERSION_PARAM':'version',
'DEFAULT_VERSION':'v1',
'ALLOWED_VERSIONS':['v1','v2'],
# 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.HostNameVersioning"
'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.URLPathVersioning"
}
--------执行determine_version获取版本
def determine_version(self, request, *args, **kwargs):
version = kwargs.get(self.version_param, self.default_version)
if not self.is_allowed_version(version):
raise exceptions.NotFound(self.invalid_version_message)
return version
---------执行reverse反向生成url
def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):
if request.version is not None:
kwargs = {} if (kwargs is None) else kwargs
kwargs[self.version_param] = request.version
return super(URLPathVersioning, self).reverse(
viewname, args, kwargs, request, format, **extra
)
-------自定制settings
REST_FRAMEWORK = {
'VERSION_PARAM':'version',
'DEFAULT_VERSION':'v1',
'ALLOWED_VERSIONS':['v1','v2'],
# 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.HostNameVersioning"
# 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.URLPathVersioning"
}
认证-----执行完上面的方法,再执行perform_authentication方法来进行认证操作----------------执行认证功能,确认进行后续操作的用户是被允许的，
perform_authentication方法返回经过认证的用户对象，
传入的request是重新封装过的。
def perform_authentication(self, request):
request.user
------然后就在request.user中执行authenticate这个方法进行认证
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
检查权限-----执行check_permissions方法--------------------------------------------------如果用户通过认证,检查用户是否有权限访问url中所传的路径，
如用用户访问的是没有没有权限的路径,则会抛出异常.
def check_permissions(self, request):
for permission in self.get_permissions():
if not permission.has_permission(request, self):
self.permission_denied(
request, message=getattr(permission, 'message', None)
)
------循环，执行get_permissions返回一个列表对象。
def get_permissions(self):
return [permission() for permission in self.permission_classes]
--------执行permission_classes，self是当前类，所以是去当前类中找，当前类中没有去父类(APIView)中找,所以可以自己定制。
permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES
----------可以看出是从api_settings中找到，我们执行api_settings
api_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS)
-------------进入APISettings，在DEFAULTS配置文件中找DEFAULT_PERMISSION_CLASSES，若自定制，自己在setting中配置。
'DEFAULT_PERMISSION_CLASSES': (
'rest_framework.permissions.AllowAny',
-------------根据配置文件可知：我们走permissions的AllowAny类。
from rest_framework.permissions import AllowAny进入
-------------AllowAny执行了has_permission，返回True.
class AllowAny(BasePermission):
"""
Allow any access.
This isn't strictly required, since you could use an empty
permission_classes list, but it's useful because it makes the intention
more explicit.
"""
def has_permission(self, request, view):
return True
),
-------------可以看出AllowAny继承了BasePermission，由此我们可以知道必须执行一个AllowAny
自己有执行自己的，自己没有没有执行父类的，都返回True
class BasePermission(object):
"""
A base class from which all permission classes should inherit.
"""
def has_permission(self, request, view):
"""
Return `True` if permission is granted, `False` otherwise.
"""
return True
def has_object_permission(self, request, view, obj):
"""
Return `True` if permission is granted, `False` otherwise.
"""
return True
检查限制访问(分流)-----就会执行check_throttles方法--------------------------------------作用是检查用户是否被限制了访问主机的次数
self.check_throttles(request) 如果用户访问服务器的次数超出设定值,则会抛出一个异常
---------例如,如果想限制一个ip地址每秒钟只能访问几次,一个小时之内最多可以访问多少次,就可以在settings.py文件中进行配置
def check_throttles(self, request):
for throttle in self.get_throttles():
if not throttle.allow_request(request, self):
self.throttled(request, throttle.wait())
----------循环执行，执行get_throttles,返回一个列表对象
def get_throttles(self):
"""
Instantiates and returns the list of throttles that this view uses.
"""
return [throttle() for throttle in self.throttle_classes]
----------执行throttle_classes，self是当前类，请求过来首先在自己的类中找，没有去父类中找(APIView)
throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES
----------可以看出是从api_settings中找到，我们执行api_settings
api_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS)
----------进入APISettings，在DEFAULTS配置文件中找DEFAULT_PERMISSION_CLASSES，若自定制，自己在setting中配置
'DEFAULT_THROTTLE_CLASSES': (),
'DEFAULT_CONTENT_NEGOTIATION_CLASS': 'rest_framework.negotiation.DefaultContentNegotiation',
'DEFAULT_METADATA_CLASS': 'rest_framework.metadata.SimpleMetadata',
'DEFAULT_VERSIONING_CLASS': None,
----------根据配置文件可知：
from rest_framework.permissions import AllowAny进入
三：执行对应的视图函数
8：---initial这个方法执行完成后,request.method.lower把请求的方法转换成小写
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)
9：---再通过通过反射的方式来执行UsersView类中的get或post等自定义方法要注意的是,在执行initial方法之前,使用了try/except方法来进行异常处理
如果执行initial方法的时候出现错误,就调用handle_exception来处理initial方法抛出的异常,返回正确的响应信息
def handle_exception(self, exc):
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
10:---在前面,如果initial方法执行完成没有抛出异常,则根据反射执行自定义的请求方法,然后返回响应信息如果initial方法抛出异常则执行handle_exception
方法处理抛出的异常,也返回响应信息等到上面的过程执行完成后,再执行finalize_response方法把最终的响应信息返回给客户端的浏览器
def finalize_response(self, request, response, *args, **kwargs):
# 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
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 dispatch(self, request, *args, **kwargs):
self.args = args
self.kwargs = kwargs
# ####################### 第一步 request二次封装 #######################
"""
return Request(
request,
parsers=self.get_parsers(), 解析相关 对象列表
authenticators=self.get_authenticators(), 认证相关 对象列表
negotiator=self.get_content_negotiator(), 选择相关 选择对象
parser_context=parser_context 解析内容
)
"""
request = self.initialize_request(request, *args, **kwargs)
self.request = request
self.headers = self.default_response_headers # deprecate?
# ####################### 第二步 初始化 #######################
"""
2.1 获取版本
返回(scheme.determine_version(request, *args, **kwargs), scheme)
request.version, request.versioning_scheme =版本号，检查版本的对象
2.2 认证
self.perform_authentication(request)
调用request.user方法
2.3 检查权限
self.check_permissions(request)
获取权限的对象列表
执行对象.has_permission方法 返回True有权限，返回False没有权限，抛出异常，message定制错误信息。
2.4 检查限制访问
self.check_throttles(request)
获取限制类的对象列表
执行对象.allow_request(request, self) 返回True可以访问，返回False限制访问。
"""
try:
self.initial(request, *args, **kwargs)
# ####################### 第三步 执行对应的视图函数 #######################
# 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
基本流程
1：请求到来之后，都要执行dispatch方法，dispatch方法根据请求方式不同触发。
2：重要的功能是在APIView的dispatch中触发。
url.py
from django.conf.urls import url, include
from web.views.s1_api import TestView
urlpatterns = [
url(r'^test/', TestView.as_view()),
]
views.py
from rest_framework.views import APIView
from rest_framework.response import Response
class TestView(APIView):
def dispatch(self, request, *args, **kwargs):
"""
请求到来之后，都要执行dispatch方法，dispatch方法根据请求方式不同触发 get/post/put等方法
注意：APIView中的dispatch方法有好多好多的功能
"""
return super().dispatch(request, *args, **kwargs)
def get(self, request, *args, **kwargs):
return Response('GET请求，响应内容')
def post(self, request, *args, **kwargs):
return Response('POST请求，响应内容')
def put(self, request, *args, **kwargs):
return Response('PUT请求，响应内容')
restful(表者征状态转移，面向资源编程)------------------------------------------->约定从资源的角度审视整个网络，将分布在网络中某个节点的资源通过url进行标识，客户端通过url获取资源的表征，获得这些表征使应用转变状态。-----------------------------------------------------------是一种软件架构风格。所有数据是通过网络获取的是操作的数据(增删改查)，都是资源-------------------------------互联网上的一切东西都视为资源。restf规则：API与用户的通信协议，使用的是http协议1：域名尽量部署在专有域名之下，若API很简单，不会进一步扩展,可以考虑放在主域名下。2：应将api的版本号放入url,还可以将版本号放入Http请求头信息中，但不如放在url中方便。3：在RESTful架构中，每个网址代表一种资源（resource），所以网址中应该有动词，应该使用名词， 而且所用的名词往往与数据库的表格名对应。一般来说，数据库中的表都是同种记录的"集合"（collection），所以API中的名词也应该使用复数。4：用于区别url接口应将API加入到url.5: 如果记录数量很多，服务器不可能都将它们返回给用户。API应该提供参数，过滤返回结果。6: 服务器向用户返回的状态码和提示信息。8: 如果状态码是4xx，就应该向用户返回出错信息。一般来说，返回的信息中将error作为键名，出错信息作为键值即可。9: 请求方式的不同，进行不同的操作。post----get----put----patch----delete10：返回错误信息
restful-api:API与用户的通行协议，总是使用HTTPs协议api:---------------------------------------------------------------------------------------接口用途：1：为别人提供服务----------发送短信2：前后端分离--------------前后端分离规范：1:url+apihttps://api.example.com------------------------------------------------------------尽量将API部署在专用域名（会存在跨域问题)https://example.org/api/-----------------------------------------------------------API很简单2:名词资源名必须是名词，不能是动词.......3:版本URL，-------------------------------------------------------------------------------如：https://api.example.com/v1/请求头------------------------------------------------------------------------------跨域时，引发发送多次请求4:提交方式------------------------------------------------------------methodGET：-------------------------------------------------------------------------------从服务器取出资源（一项或多项）POST：------------------------------------------------------------------------------在服务器新建一个资源PUT：-------------------------------------------------------------------------------在服务器更新资源（客户端提供改变后的完整资源）PATCH ：----------------------------------------------------------------------------在服务器更新资源（客户端提供改变的属性）DELETE：----------------------------------------------------------------------------从服务器删除资源5:json数据------------------------------------------------------------返回json数据6:status--------------------------------------------------------------状态码200 OK - [GET]：服务器成功返回用户请求的数据，该操作是幂等的（Idempotent）。201 CREATED - [POST/PUT/PATCH]：用户新建或修改数据成功。202 Accepted - [*]：表示一个请求已经进入后台排队（异步任务）204 NO CONTENT - [DELETE]：用户删除数据成功。400 INVALID REQUEST - [POST/PUT/PATCH]：用户发出的请求有错误，服务器没有进行新建或修改数据的操作，该操作是幂等的。401 Unauthorized - [*]：表示用户没有权限（令牌、用户名、密码错误）。403 Forbidden - [*] 表示用户得到授权（与401错误相对），但是访问是被禁止的。404 NOT FOUND - [*]：用户发出的请求针对的是不存在的记录，服务器没有进行操作，该操作是幂等的。406 Not Acceptable - [GET]：用户请求的格式不可得（比如用户请求JSON格式，但是只有XML格式）。410 Gone -[GET]：用户请求的资源被永久删除，且不会再得到的。422 Unprocesable entity - [POST/PUT/PATCH] 当创建一个对象时，发生一个验证错误。500 INTERNAL SERVER ERROR - [*]：服务器发生错误，用户将无法判断发出的请求是否成功。更多看这里：http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html7:aypermedia link-----------------------------------------------------返回链接Hypermedia API，RESTful API最好做到Hypermedia，即返回结果中提供链接，连向其他API方法，使得用户不查文档，也知道下一步应该做什么。{"link": { "rel": "collection https://www.example.com/zoos", "href": "https://api.example.com/zoos", "title": "List of zoos", "type": "application/vnd.yourformat+json"}}8:错误处理错误处理，状态码是4xx时，应返回错误信息，error当做key。{error: "Invalid API key"}为什么做前后端分离？数据的解耦，提高开发效率。
安装：pip3 install djangorestframework -i http://pypi.douban.com/simple/ --trusted-host=pypi.douban.com继承关系：class View(object):-------------------------------------------------viewclass APIView(View):------------------------------------------------APIviewclass GenericAPIView(views.APIView):--------------------------------GenericAPIViewclass GenericViewSet(ViewSetMixin, generics.GenericAPIView)---------GenericViewSetclass ModelViewSet(mixins.CreateModelMixin,-------------------------ModelViewSet(增删改查，genericViewset) mixins.RetrieveModelMixin, mixins.UpdateModelMixin, mixins.DestroyModelMixin, mixins.ListModelMixin, GenericViewSet):Django Rest Framework 的的请求生命周期：hTTP请求 —> wsgi —> 中间件 —> 路由分发 —> 执行对应类的dispatch方法 —> 视图函数 —>返回 采用CBV的请求方式。
源码剖析接收HTTP请求---->wsgi----->中间件------->路由分发---------->执行对应类的dispatch方法------->视图函数------>返回首先执行 as_view 我们可以知道，as_view调用了dispatch.执行：------------------------>执行对应类的dispatch方法：---------------------dispatch一：第一步对------------------------------------------------------------------request二次封装1：--查看initialize_request方法,可以知道这个方法接收客户端的request请求,再重新封装成新的request。def initialize_request(self, request, *args, **kwargs):parser_context = self.get_parser_context(request)
return Request(request,parsers=self.get_parsers(),authenticators=self.get_authenticators(),negotiator=self.get_content_negotiator(),parser_context=parser_context)点击进入Request2:----再查看Request方法的源码，可以知道这个Request类是rest framework中定义的一个类----Rquest类,这来类是经过Request处理过的request已经不再是客户端发送过来的那个request了class Request(object):def __init__(self, request, parsers=None, authenticators=None, negotiator=None, parser_context=None):self._request = requestself.parsers = parsers or ()self.authenticators = authenticators or ()self.negotiator = negotiator or self._default_negotiator()self.parser_context = parser_contextself._data = Emptyself._files = Emptyself._full_data = Emptyself._content_type = Emptyself._stream = Empty
if self.parser_context is None:self.parser_context = {}self.parser_context['request'] = selfself.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,)3:----在initialize_request方法中,有一个方法处理过request,来看看get_parser_context方法的源码在这里,view的值是self,代指的是UsersView这个对象,所以get_parser_context方法把UsersView这个类封装进来然后返回所以get_parser_context方法最后返回的当前对象以及当前对象所传的参数，经过initialize_request函数处理之后的request,现在就变成了Request(request,parsers=self.get_parsers(),authenticators=self.get_authenticators(),negotiator=self.get_content_negotiator(),parser_context=parser_context) def get_parser_context(self, http_request):return {'view': self, #代指的是UsersView这个对象'args': getattr(self, 'args', ()),'kwargs': getattr(self, 'kwargs', {})} 4:----现在再来看看Request的其他参数代指的是什么get_parsers------------------根据字面意思,是解析get请求的意思def get_parsers(self):return [parser() for parser in self.parser_classes]get_content_negotiator-------选择相关def get_content_negotiator(self):if not getattr(self, '_negotiator', None):self._negotiator = self.content_negotiation_class()return self._negotiatorparser_context---------------封闭self和self的参数 parser_context = self.get_parser_context(request) *get_authenticators----------------------认证相关,在get_authenticators这个方法中循环了self.authentication_classes返回了一个列表对象，def get_authenticators(self):return [auth() for auth in self.authentication_classes]----------他是self.找的，所有它先去我们写的那个类中去找authentication_classes，我们写的类中没有才去父类中找，因此我们就可以自定义这个列表类了。 进入APIview类找------------------authentication_classesclass APIView(View):# The following policies may be set at either globally, or per-view.renderer_classes = api_settings.DEFAULT_RENDERER_CLASSESparser_classes = api_settings.DEFAULT_PARSER_CLASSESauthentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES #认证throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES #权限permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES #分流content_negotiation_class = api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASSmetadata_class = api_settings.DEFAULT_METADATA_CLASSversioning_class = api_settings.DEFAULT_VERSIONING_CLASS..............------------authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES由此可以看出:它默认的authentication_classes是从它的配置文件中读出来的。现在就可以去看看它配置文件中的类了。 -------------进入api_settings可以看到api_settings=APISettingsapi_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS)-----------进入APISettings，默认的authentication_classes是从它的配置文件中读出来的。现在就可以去看看它配置文件中的类了DEFAULTS = {# Base API policies'DEFAULT_RENDERER_CLASSES': ('rest_framework.renderers.JSONRenderer','rest_framework.renderers.BrowsableAPIRenderer',),'DEFAULT_PARSER_CLASSES': ('rest_framework.parsers.JSONParser','rest_framework.parsers.FormParser','rest_framework.parsers.MultiPartParser'),'DEFAULT_AUTHENTICATION_CLASSES': ('rest_framework.authentication.SessionAuthentication','rest_framework.authentication.BasicAuthentication'),'DEFAULT_PERMISSION_CLASSES': ('rest_framework.permissions.AllowAny',),'DEFAULT_THROTTLE_CLASSES': (),'DEFAULT_CONTENT_NEGOTIATION_CLASS': 'rest_framework.negotiation.DefaultContentNegotiation','DEFAULT_METADATA_CLASS': 'rest_framework.metadata.SimpleMetadata','DEFAULT_VERSIONING_CLASS': None,
# Generic view behavior'DEFAULT_PAGINATION_CLASS': None,'DEFAULT_FILTER_BACKENDS': (),
# Schema'DEFAULT_SCHEMA_CLASS': 'rest_framework.schemas.AutoSchema',
# Throttling'DEFAULT_THROTTLE_RATES': {'user': None,'anon': None,},'NUM_PROXIES': None,
# Pagination'PAGE_SIZE': None,
# Filtering'SEARCH_PARAM': 'search','ORDERING_PARAM': 'ordering',
# Versioning'DEFAULT_VERSION': None,'ALLOWED_VERSIONS': None,'VERSION_PARAM': 'version',
# Authentication'UNAUTHENTICATED_USER': 'django.contrib.auth.models.AnonymousUser','UNAUTHENTICATED_TOKEN': None,
# View configuration'VIEW_NAME_FUNCTION': 'rest_framework.views.get_view_name','VIEW_DESCRIPTION_FUNCTION': 'rest_framework.views.get_view_description',
# Exception handling'EXCEPTION_HANDLER': 'rest_framework.views.exception_handler','NON_FIELD_ERRORS_KEY': 'non_field_errors',
# Testing'TEST_REQUEST_RENDERER_CLASSES': ('rest_framework.renderers.MultiPartRenderer','rest_framework.renderers.JSONRenderer'),'TEST_REQUEST_DEFAULT_FORMAT': 'multipart',
# Hyperlink settings'URL_FORMAT_OVERRIDE': 'format','FORMAT_SUFFIX_KWARG': 'format','URL_FIELD_NAME': 'url',
# Input and output formats'DATE_FORMAT': ISO_8601,'DATE_INPUT_FORMATS': (ISO_8601,),
'DATETIME_FORMAT': ISO_8601,'DATETIME_INPUT_FORMATS': (ISO_8601,),
'TIME_FORMAT': ISO_8601,'TIME_INPUT_FORMATS': (ISO_8601,),
# Encoding'UNICODE_JSON': True,'COMPACT_JSON': True,'STRICT_JSON': True,'COERCE_DECIMAL_TO_STRING': True,'UPLOADED_FILES_USE_URL': True,
# Browseable API'HTML_SELECT_CUTOFF': 1000,'HTML_SELECT_CUTOFF_TEXT': "More than {count} items...",
# Schemas'SCHEMA_COERCE_PATH_PK': True,'SCHEMA_COERCE_METHOD_NAMES': {'retrieve': 'read','destroy': 'delete'},}-----------找到DEFAULT_AUTHENTICATION_CLASSES可以看出他有两个类是在authentication中：SessionAuthentication，BasicAuthentication，'DEFAULT_AUTHENTICATION_CLASSES': ('rest_framework.authentication.SessionAuthentication','rest_framework.authentication.BasicAuthentication'),--------------from rest_framework import authentication进入--------------SessionAuthentication class SessionAuthentication(BaseAuthentication):"""Use Django's session framework for authentication."""
def authenticate(self, request):"""Returns a `User` if the request session currently has a logged in user.Otherwise returns `None`."""
# Get the session-based user from the underlying HttpRequest objectuser = getattr(request._request, 'user', None)
# Unauthenticated, CSRF validation not requiredif not user or not user.is_active:return None
self.enforce_csrf(request)
# CSRF passed with authenticated userreturn (user, None)
def enforce_csrf(self, request):"""Enforce CSRF validation for session based authentication."""reason = CSRFCheck().process_view(request, None, (), {})if reason:# CSRF failed, bail with explicit error messageraise exceptions.PermissionDenied('CSRF Failed: %s' % reason)--------------BasicAuthentication 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 suppliedusing HTTP Basic authentication. Otherwise returns `None`."""auth = get_authorization_header(request).split()
if not auth or auth[0].lower() != b'basic':return None
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(':')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]return self.authenticate_credentials(userid, password, request)
def authenticate_credentials(self, userid, password, request=None):"""Authenticate the userid and password against username and passwordwith 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 --------------可以看出他们都继承了一个BaseAuthentication的类并且都实现了authenticate方法。 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 theauthentication scheme should return `403 Permission Denied` responses."""pass--------------进入authenticate，由此可以看出BaseAuthentication类其实是一个接口类，让继承它的类必须实现authenticate方法。 最后就是在request对象中的authenticatotes中封装了一些关于认证的对。def authenticate(self, request):"""Authenticate the request and return a two-tuple of (user, token)."""raise NotImplementedError(".authenticate() must be overridden.") -----------自己添加配置文件-------settings:若将自己定义的认证类添加的返回的列表，就通过seettings的配置走自己的定义的认证类EST_FRAMEWORK = {'UNAUTHENTICATED_USER': None,'UNAUTHENTICATED_TOKEN': None,"DEFAULT_AUTHENTICATION_CLASSES": [# "app01.utils.MyAuthentication",],'DEFAULT_PERMISSION_CLASSES':[
],'DEFAULT_THROTTLE_RATES':{'wdp_anon':'5/minute','wdp_user':'10/minute',
}}5:---再来看看UsersView这个类中的get方法和post方法----------------------------------------------------------------UserView可以看到get方法的参数中有一个request,通过前面可以知道这个request已经不是最开始时到达服务端的request了这个request方法中已经被REST framework封装了解析,认证和选择等相关的方法def get(self,request,*args,**kwargs):passdef post(self,request,*args,**kwargs):pass6：---efault_response_headers这个方法从它的注释可以看出已经被丢弃了.二：初始化--------------------------------------------------------------------获取版本-----认证-----权限-----分流7：---再来看initial这个方法def initial(self, request, *args, **kwargs):self.format_kwarg = self.get_format_suffix(**kwargs)# Perform content negotiation and store the accepted info on the request#执行内容协商并将接受的信息存储在请求上neg = self.perform_content_negotiation(request)request.accepted_renderer, request.accepted_media_type = neg# Determine the API version, if versioning is in use.#如果正在使用版本控制，请确定API版本。version, scheme = self.determine_version(request, *args, **kwargs)request.version, request.versioning_scheme = version, scheme# Ensure that the incoming request is permitted#确保传入的请求是允许的。self.perform_authentication(request)self.check_permissions(request)self.check_throttles(request)----先执行get_format_suffix-------------------------------------------------------------来获取客户端所发送的url的后缀
----然后执行perform_content_negotiation方法,--------------------------------------------这个方法的主要作用是执行内容选择,并把服务端接收到的信息保存在request中获取版本----然后再执行determine_version方法---------------------------------------------如果url中有版本信息,就获取发送到服务端的版本,返回一个元组 -------version,schemas是执行determine_version获得的，versioning_scheme是设置类的对象也就是QueryParameterVersioning。request.version就是QueryParameterVersioning执行etermine_version version, scheme = self.determine_version(request, *args, **kwargs) request.version, request.versioning_scheme = version, scheme--------执行determine_version，如果versioning是空的，就返回两个空。，不为空走versioning设置值。def determine_version(self, request, *args, **kwargs):if self.versioning_class is None:return (None, None)scheme = self.versioning_class()return (scheme.determine_version(request, *args, **kwargs), scheme)---------走versiong_class设置值，走api_settings配置找DEFAULT_VERSIONING_CLASS versioning_class = api_settings.DEFAULT_VERSIONING_CLASS ----------走api_settings寻找配置 api_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS)---------api_settings = APISettings，走APISettings找DEFAULT_VERSIONING_CLASS。默认为空，需自己设置。 'DEFAULT_VERSIONING_CLASS': None,---------进入QueryParameterVersioningclass QueryParameterVersioning(BaseVersioning):"""GET /something/?version=0.1 HTTP/1.1Host: example.comAccept: application/json"""invalid_version_message = _('Invalid version in query parameter.')
def determine_version(self, request, *args, **kwargs):version = request.query_params.get(self.version_param, self.default_version)if not self.is_allowed_version(version):raise exceptions.NotFound(self.invalid_version_message)return version
def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):url = super(QueryParameterVersioning, self).reverse(viewname, args, kwargs, request, format, **extra)if request.version is not None:return replace_query_param(url, self.version_param, request.version)return url---------获取version,version_param就是配置def determine_version(self, request, *args, **kwargs):version = request.query_params.get(self.version_param, self.default_version)if not self.is_allowed_version(version):raise exceptions.NotFound(self.invalid_version_message)return version---------进入version_param，在配置中找VERSION_PARAM version_param = api_settings.VERSION_PARAM ---------由配置可知VERSION_PARAM等于version.'VERSION_PARAM': 'version',---------default_version=配置中的DEFAULT_VERSIONdefault_version = api_settings.DEFAULT_VERSION ---------进入配置找DEFAULT_VERSION，可以知道我们可以在setting中自己配置---------is_allowed_version是允许的版本，也可自己在seettings中配置。流程相似 -------from rest_framework.versioning import QueryParameterVersioning,URLPathVersioning---------QueryParameterVersioningclass QueryParameterVersioning(BaseVersioning):"""GET /something/?version=0.1 HTTP/1.1Host: example.comAccept: application/json"""invalid_version_message = _('Invalid version in query parameter.')
def determine_version(self, request, *args, **kwargs):version = request.query_params.get(self.version_param, self.default_version)if not self.is_allowed_version(version):raise exceptions.NotFound(self.invalid_version_message)return version
def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):url = super(QueryParameterVersioning, self).reverse(viewname, args, kwargs, request, format, **extra)if request.version is not None:return replace_query_param(url, self.version_param, request.version)return url--------执行determine_version获取版本def determine_version(self, request, *args, **kwargs):version = request.query_params.get(self.version_param, self.default_version)if not self.is_allowed_version(version):raise exceptions.NotFound(self.invalid_version_message)return version--------执行reverse反向生成urldef reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):url = super(QueryParameterVersioning, self).reverse(viewname, args, kwargs, request, format, **extra)if request.version is not None:return replace_query_param(url, self.version_param, request.version)return url---------URLPathVersioningclass URLPathVersioning(BaseVersioning):"""To the client this is the same style as `NamespaceVersioning`.The difference is in the backend - this implementation usesDjango's URL keyword arguments to determine the version.
An example URL conf for two views that accept two different versions.
urlpatterns = [url(r'^(?P<version>[v1|v2]+)/users/$', users_list, name='users-list'),url(r'^(?P<version>[v1|v2]+)/users/(?P<pk>[0-9]+)/$', users_detail, name='users-detail')]
GET /1.0/something/ HTTP/1.1Host: example.comAccept: application/json"""invalid_version_message = _('Invalid version in URL path.')
def determine_version(self, request, *args, **kwargs):version = kwargs.get(self.version_param, self.default_version)if not self.is_allowed_version(version):raise exceptions.NotFound(self.invalid_version_message)return version
def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):if request.version is not None:kwargs = {} if (kwargs is None) else kwargskwargs[self.version_param] = request.version
return super(URLPathVersioning, self).reverse(viewname, args, kwargs, request, format, **extra) ---------自己在settings中配置REST_FRAMEWORK = {'VERSION_PARAM':'version','DEFAULT_VERSION':'v1','ALLOWED_VERSIONS':['v1','v2'],# 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.HostNameVersioning"'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.URLPathVersioning"}--------执行determine_version获取版本def determine_version(self, request, *args, **kwargs):version = kwargs.get(self.version_param, self.default_version)if not self.is_allowed_version(version):raise exceptions.NotFound(self.invalid_version_message)return version---------执行reverse反向生成urldef reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra):if request.version is not None:kwargs = {} if (kwargs is None) else kwargskwargs[self.version_param] = request.version
return super(URLPathVersioning, self).reverse(viewname, args, kwargs, request, format, **extra) -------自定制settingsREST_FRAMEWORK = {'VERSION_PARAM':'version','DEFAULT_VERSION':'v1','ALLOWED_VERSIONS':['v1','v2'],# 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.HostNameVersioning"# 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.URLPathVersioning"}认证-----执行完上面的方法,再执行perform_authentication方法来进行认证操作----------------执行认证功能,确认进行后续操作的用户是被允许的，perform_authentication方法返回经过认证的用户对象，传入的request是重新封装过的。def perform_authentication(self, request):request.user------然后就在request.user中执行authenticate这个方法进行认证 def user(self):"""Returns the user associated with the current request, as authenticatedby the authentication classes provided to the request."""if not hasattr(self, '_user'):with wrap_attributeerrors():self._authenticate()return self._user检查权限-----执行check_permissions方法--------------------------------------------------如果用户通过认证,检查用户是否有权限访问url中所传的路径，如用用户访问的是没有没有权限的路径,则会抛出异常. def check_permissions(self, request):for permission in self.get_permissions():if not permission.has_permission(request, self):self.permission_denied(request, message=getattr(permission, 'message', None))------循环，执行get_permissions返回一个列表对象。 def get_permissions(self):return [permission() for permission in self.permission_classes]--------执行permission_classes，self是当前类，所以是去当前类中找，当前类中没有去父类(APIView)中找,所以可以自己定制。permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES----------可以看出是从api_settings中找到，我们执行api_settingsapi_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS)-------------进入APISettings，在DEFAULTS配置文件中找DEFAULT_PERMISSION_CLASSES，若自定制，自己在setting中配置。'DEFAULT_PERMISSION_CLASSES': ('rest_framework.permissions.AllowAny',-------------根据配置文件可知：我们走permissions的AllowAny类。from rest_framework.permissions import AllowAny进入-------------AllowAny执行了has_permission，返回True.class AllowAny(BasePermission):"""Allow any access.This isn't strictly required, since you could use an emptypermission_classes list, but it's useful because it makes the intentionmore explicit."""
def has_permission(self, request, view):return True),-------------可以看出AllowAny继承了BasePermission，由此我们可以知道必须执行一个AllowAny自己有执行自己的，自己没有没有执行父类的，都返回Trueclass BasePermission(object):"""A base class from which all permission classes should inherit."""
def has_permission(self, request, view):"""Return `True` if permission is granted, `False` otherwise."""return True
def has_object_permission(self, request, view, obj):"""Return `True` if permission is granted, `False` otherwise."""return True检查限制访问(分流)-----就会执行check_throttles方法--------------------------------------作用是检查用户是否被限制了访问主机的次数self.check_throttles(request) 如果用户访问服务器的次数超出设定值,则会抛出一个异常---------例如,如果想限制一个ip地址每秒钟只能访问几次,一个小时之内最多可以访问多少次,就可以在settings.py文件中进行配置 def check_throttles(self, request):for throttle in self.get_throttles():if not throttle.allow_request(request, self):self.throttled(request, throttle.wait())----------循环执行，执行get_throttles,返回一个列表对象 def get_throttles(self):"""Instantiates and returns the list of throttles that this view uses."""return [throttle() for throttle in self.throttle_classes]----------执行throttle_classes，self是当前类，请求过来首先在自己的类中找，没有去父类中找(APIView) throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES----------可以看出是从api_settings中找到，我们执行api_settings api_settings = APISettings(None, DEFAULTS, IMPORT_STRINGS)----------进入APISettings，在DEFAULTS配置文件中找DEFAULT_PERMISSION_CLASSES，若自定制，自己在setting中配置'DEFAULT_THROTTLE_CLASSES': (),'DEFAULT_CONTENT_NEGOTIATION_CLASS': 'rest_framework.negotiation.DefaultContentNegotiation','DEFAULT_METADATA_CLASS': 'rest_framework.metadata.SimpleMetadata','DEFAULT_VERSIONING_CLASS': None,----------根据配置文件可知：from rest_framework.permissions import AllowAny进入三：执行对应的视图函数8：---initial这个方法执行完成后,request.method.lower把请求的方法转换成小写 Get the appropriate handler methodif 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)9：---再通过通过反射的方式来执行UsersView类中的get或post等自定义方法要注意的是,在执行initial方法之前,使用了try/except方法来进行异常处理 如果执行initial方法的时候出现错误,就调用handle_exception来处理initial方法抛出的异常,返回正确的响应信息def handle_exception(self, exc):if isinstance(exc, (exceptions.NotAuthenticated,exceptions.AuthenticationFailed)):# WWW-Authenticate header for 401 responses, else coerce to 403auth_header = self.get_authenticate_header(self.request)
if auth_header:exc.auth_header = auth_headerelse: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 = Truereturn response10:---在前面,如果initial方法执行完成没有抛出异常,则根据反射执行自定义的请求方法,然后返回响应信息如果initial方法抛出异常则执行handle_exception 方法处理抛出的异常,也返回响应信息等到上面的过程执行完成后,再执行finalize_response方法把最终的响应信息返回给客户端的浏览器 def finalize_response(self, request, response, *args, **kwargs):# Make the error obvious if a proper response is not returnedassert 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_rendererresponse.accepted_media_type = request.accepted_media_typeresponse.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 responsedef dispatch(self, request, *args, **kwargs):self.args = argsself.kwargs = kwargs# ####################### 第一步 request二次封装 #######################"""return Request(request,parsers=self.get_parsers(), 解析相关 对象列表authenticators=self.get_authenticators(), 认证相关 对象列表negotiator=self.get_content_negotiator(), 选择相关 选择对象parser_context=parser_context 解析内容)"""request = self.initialize_request(request, *args, **kwargs)self.request = requestself.headers = self.default_response_headers # deprecate?
# ####################### 第二步 初始化 #######################"""2.1 获取版本返回(scheme.determine_version(request, *args, **kwargs), scheme)request.version, request.versioning_scheme =版本号，检查版本的对象2.2 认证 self.perform_authentication(request)调用request.user方法2.3 检查权限self.check_permissions(request) 获取权限的对象列表 执行对象.has_permission方法 返回True有权限，返回False没有权限，抛出异常，message定制错误信息。2.4 检查限制访问self.check_throttles(request)获取限制类的对象列表执行对象.allow_request(request, self) 返回True可以访问，返回False限制访问。
"""try:self.initial(request, *args, **kwargs)# ####################### 第三步 执行对应的视图函数 #######################
# Get the appropriate handler methodif 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
基本流程1：请求到来之后，都要执行dispatch方法，dispatch方法根据请求方式不同触发。2：重要的功能是在APIView的dispatch中触发。url.pyfrom django.conf.urls import url, includefrom web.views.s1_api import TestViewurlpatterns = [url(r'^test/', TestView.as_view()),]views.pyfrom rest_framework.views import APIViewfrom rest_framework.response import Responseclass TestView(APIView):def dispatch(self, request, *args, **kwargs):"""请求到来之后，都要执行dispatch方法，dispatch方法根据请求方式不同触发 get/post/put等方法注意：APIView中的dispatch方法有好多好多的功能"""return super().dispatch(request, *args, **kwargs) def get(self, request, *args, **kwargs):return Response('GET请求，响应内容') def post(self, request, *args, **kwargs):return Response('POST请求，响应内容') def put(self, request, *args, **kwargs):return Response('PUT请求，响应内容')