标签：fun patch spl function pre pip3 sage from response
Flask本身没有信号，需要安装第三方组件。Flask框架中的信号基于blinker，其主要就是让开发者可是在flask请求过程中定制一些用户行为。
pip3 install blinker
request_started = _signals.signal(‘request-started‘) # 请求到来前执行 request_finished = _signals.signal(‘request-finished‘) # 请求结束后执行 before_render_template = _signals.signal(‘before-render-template‘) # 模板渲染前执行 template_rendered = _signals.signal(‘template-rendered‘) # 模板渲染后执行 got_request_exception = _signals.signal(‘got-request-exception‘) # 请求执行出现异常时执行 request_tearing_down = _signals.signal(‘request-tearing-down‘) # 请求执行完毕后自动执行（无论成功与否） appcontext_tearing_down = _signals.signal(‘appcontext-tearing-down‘)# 应用上下文执行完毕后自动执行（无论成功与否） appcontext_pushed = _signals.signal(‘appcontext-pushed‘) # 应用上下文push时执行 appcontext_popped = _signals.signal(‘appcontext-popped‘) # 应用上下文pop时执行 message_flashed = _signals.signal(‘message-flashed‘) # 调用flask在其中添加数据时，自动触发
部分源码流程：
class Flask(_PackageBoundObject): def full_dispatch_request(self): self.try_trigger_before_first_request_functions() try: ########## 触发request_started信号 ########## request_started.send(self) rv = self.preprocess_request() if rv is None: rv = self.dispatch_request() except Exception as e: rv = self.handle_user_exception(e) return self.finalize_request(rv) def wsgi_app(self, environ, start_response): ctx = self.request_context(environ) error = None try: try: ctx.push() response = self.full_dispatch_request() except Exception as e: error = e response = self.handle_exception(e) except: error = sys.exc_info()[1] raise return response(environ, start_response) finally: if self.should_ignore_error(error): error = None ctx.auto_pop(error)
class Flask(_PackageBoundObject): def finalize_request(self, rv, from_error_handler=False): response = self.make_response(rv) try: response = self.process_response(response) ########## request_finished信号 ########## request_finished.send(self, response=response) except Exception: if not from_error_handler: raise self.logger.exception(‘Request finalizing failed with an error while handling an error‘) return response
from flask import Flask, current_app, flash, render_template from flask.signals import _signals app = Flask(import_name=__name__) # 自定义信号 xx = _signals.signal("xx") def func(sender, *args, **kwargs): print(sender, args, kwargs) # 123 () {‘k1‘: ‘v1‘} # 自定义信号中注册函数 xx.connect(func) @app.route("/index") def index(): # 触发信号 xx.send("123", k1="v1") return "index" if __name__ == "__main__": app.run()
标签：fun patch spl function pre pip3 sage from response
原文地址：https://www.cnblogs.com/believepd/p/10397069.html
