Flask 信号机制

flask信号

信号使用详解:

• 信号使用分为三步

• 定义信号

  • ```python
    from flask import Flask
    from signal import visit_signalapp = Flask(name)@app.route(‘/‘)
    def func1():

    username = request.args.get('username')
    if username:
        g.user = username
        visit_signal.send()
    else:
        return 'hello world'
    

    - ```python
      from blinker import Namespace
      my_pace = Namepace()
      visit_signal = my_pace.signal('visit-signal')
      def func(sender):
          from flask import g
          print(g.user)
      visit_signal.connect(func)

• 监听信号

  • ```python
    visit_signal.send()
    #设置监听

    ------
    
    ### flask自带的信号机制:
    
    #### 		模板渲染时传出的信号:
    
    - ```python
      #正常信号监听
      from flask import Flask,render_template,template_rendered
      app = Flask(__name__)
      ***********************************************************
      #其一
      def template_rendered_func(sender,template,context):
          print('sender:',sender)
          print('template:',template)
          print('context',context)
      template_randered.context(template_rendered_func)
      ***********************************************************
      @app.route('/')
      def func1():
          return render_template('index.html')

• #异常信号监听
  from flask import Flask,render_template,template_rendered,got_request_exception
  app = Flask(__name__)
  ***********************************************************
  #其二  
  def request_exception_log(sender,*args,**kwargs):
      print(sender)
      print(args)
      print(kwargs)
  got_request_exception.connect(request_exception_log)
  ***********************************************************
  @app.route('/')
  def func1():
      return render_template('index.html')