08 Mu Class Network "Attack on node. JS Foundation (i)" Events

Referencing the Eventemitter in the events module

Monitoring and launching of events

The same number of event launches is limited, and peaks can be set via Setmaxlisteners

var Eventemitter = require (' Events '). Eventemittervarnew  eventemitter ()// plus no warning //  Life.setmaxlisteners(life.on) (' clickevent ',function(WHO) {    Console.log ( ' give ' + who + ' pour water ')}) Life.emit (' clickevent ', ' Man 1 ')

Each emit has a return value indicating whether there is a corresponding listener event

var hasclicklistener = life.emit (' clickevent ', ' Man ')var haschangelistener = Life.emit (' ChangeEvent ', ' sister 1 ') console.log (Hasclicklistener) console.log (Haschangelistener) console.log (Hasputlistener) 

Cancel Monitoring

//can be placed behind on and emit .functionWater (WHO) {Console.log (' Give ' + who + ' pour water ')}life.on (' ChangeEvent ', water)//Has not been canceled, emit cannot be put on beforeLife.emit (' ChangeEvent ', ' Zhang San ')//water can not use anonymous functions, RemoveListener need to be before emitLife.removelistener (' ChangeEvent ', water)//Remove all listeners, you can pass event names as parameters//life.removealllisteners ()varHaschangelistener = Life.emit (' changeevent ', ' sister 1 ')//The listener was canceled .varHasputlistener = Life.emit (' clickevent ', ' Li Bai ')////Whether it is monitoredConsole.log (Haschangelistener) console.log (Hasputlistener)

Number of listeners

Console.log (' changeevent: ' + life.listeners (' ChangeEvent '). Length) Console.log (' clickevent: ' + Life.listeners (' clickevent '). Length) Console.log (' all: ' + life.listeners.length)//  Eventemitter provides the method Console.log (' Eventemitter provides: ') console.log (' changeevent: ' + Eventemitter.listenercount (Life, ' ChangeEvent ')) Console.log (' clickevent: ' + eventemitter.listenercount ( Life, ' clickevent '))

08 Mu Class Network "Attack on node. JS Foundation (i)" Events