JavaScript 设计模式入门和框架中的实践

class StateTracker{
    constructor(){
         this.observers = [];
         this.internamState= 10;
     }
     // 改变内部状态，触发状态的观察者列表
     change(val){
         this.internamState= val;
         this.observers.forEach(observer=>observer(val));
     }
     registerObserver(ObserverFn){
       this.obserers.push(ObserverFn)
    }
 }

class PubSubHandler{
   constructor(){
      this.eventPool = {};
    }
    //移除
    off(topicName){
       delete this.observers[topicName]
    }
     //发布
     trigger(topicName,...args){
        this.eventPool[topicName] && 
        this.eventPool[topicName].forEach(callback=>callback(...args));
     }
     //订阅
     on(topicName,callback){
        let topic = this.eventPool[topicName] ;
        if(!topic){
            this.eventPool[topicName] =[]
        }
      this.eventPool[topicName].push(callback)
   }
}

var singleton = ()=>{
    var instance;
    var createInstance = ()=>{
        this.a = 1;
        this.b = 2;
    }
    return {
         getInstance:()=>{
            if(!instance){
               instance = createInstance();
           }
            return instance;
         }
     }
}
var test = singleton();
test.getInstance() == test.getInstance() //true

function decorator(sourceObj,decortorFn){
    decortorFn(sourceObj);
    return sourceObj
}
 var d = {a:1};
 // d变为了{a:1,b:1}
 d = decorator(d,(d)=>{d.b=1});

class StateTracker{
   constructor(){
       this.raw = {
           a:1,
            b:2
         }
     }
   mixin(obj){
        Object.assign(this.raw,obj)
   }
}

var store = createStore(reducer,initialState);//注册redux store，存储在 nextListeners数组
var test = store.subscribe(()=>{console.log('我注册了！')});// 取消注册监听 test.unsubscribe();
　publish/subscribe在jquery中的使用
$(document).on('hello',()=>{console.log('hello')})$(document).trigger('hello');$(document).off('hello')

//装饰器
@connect(state=>state)
class Container extends Component{
  render(){
     return JSON.stringify(this.props)   
   }
}