Flask请求上下文源码解析
from flask import Flask,request
app=Flask(__name__)
@app.route("/")
def index():
print(request.form)
return "1"
if __name__ == '__main__':
#self,是app,app(),--->Flask对象，Flask的__call__
app.__call__
app.run()
'''
1 app.__call__
2 wsgi_app(environ, start_response)
2.1 ctx = self.request_context(environ)
2.1.1 return RequestContext(self, environ)
这里的self是app,environ请求相关
2.1.2 return RequestContext(self, environ)
得到了RequestContext的对象，而且有request属性
2.2 2.1中的ctx就是RequestContext的对象
2.3 ctx.push()执行这个，就是RequestContext的对象的push方法
2.3.1 #执行这个，self-->ctx
_request_ctx_stack.push(self)
2.3.1.1 我们发现_request_ctx_stack = LocalStack()
他的push方法的源码：
def push(self, obj):
rv = getattr(self._local, "stack", None)
if rv is None:
# self._local=>stack-->storage['线程id']['stack']=[ctx,]
self._local.stack = rv = []
rv.append(obj)
return rv
3在请求中获取request.form
3.1 request是LocalProxy的对象，当获取属性的时候会走__getattr__
def __getattr__(self, name):
if name == "__members__":
return dir(self._get_current_object())
#name-->form,
#self._get_current_object()===>ctx.request,form
#_get_current_object()---》self.__local()
return getattr(self._get_current_object(), name)
3.1.1 self._get_current_object():源码：最终：partial(_lookup_req_object, "request")
def _get_current_object(self):
if not hasattr(self.__local, "__release_local__"):
#local==>partial(_lookup_req_object, "request")
#def __init__(self, local, name=None):
# object.__setattr__(self, "_LocalProxy__local", local)
#self.__local()===>local()
return self.__local()
try:
return getattr(self.__local, self.__name__)
except AttributeError:
raise RuntimeError("no object bound to %s" % self.__name__)
4 partial(_lookup_req_object, "request")偏函数的源码
def _lookup_req_object(name):
#name是request
#ctx
top = _request_ctx_stack.top
if top is None:
raise RuntimeError(_request_ctx_err_msg)
#ctx-->request
return getattr(top, name)
4.1中_request_ctx_stack.top
@property
def top(self):
try:
return self._local.stack[-1]
except (AttributeError, IndexError):
return None
'''
