状态模式

statusMode.js

//状态模式
//重点在于状态机的切换逻辑，以及有相同的方法代理操作（如这里的btnpressed）
var STATUS = {
  on: {
    btnpressed: function(){
      console.log('关灯了');
      this.button.innerHTML = 'ON';
      this.currentstatus = STATUS.off;
    }
  },
  off:{
    btnpressed: function(){
      console.log('开灯了');
      this.button.innerHTML = 'OFF';
      this.currentstatus = STATUS.on;
    }
  }
}

function Light(){
  this.currentstatus = STATUS.off;
  this.button = null;
}
Light.prototype.init = function(){
  var that = this;
  var btn = document.createElement('button');
  btn.innerHTML = 'ON';
  document.body.appendChild(btn);
  this.button = btn;
  this.button.onclick = function(){
    //绑定this，避免丢失
    that.currentstatus.btnpressed.call(that);
  }
}
var light = new Light();
light.init();