自定义的事件接口，作为其他类的父类使用，API接口与jQ很像

PxerEvent.class.js

class PxerEvent{
    constructor(eventList=[]){
        this.eventList =eventList;

        this._event ={};

        this._oneEvent ={};

        return new Proxy(this ,{
            get(target ,property){
                if(property in target){
                    return target[property];
                };

                let inEvent =target.eventList.some( item => property &&(item===property) );
                if(inEvent){
                    return target.dispatch.bind(target ,property);
                };


            },
        })
    };
}

PxerEvent.prototype.on =function(type, listener){

    if( !( this._checkEventType(type) && this._checkListener(listener) )) return this;

    this._event[type] ||(this._event[type]=[]);

    this._event[type].push(listener);
    return this;

};

PxerEvent.prototype.one =function(type, listener){

    if( !( this._checkEventType(type) && this._checkListener(listener) )) return this;

    this._oneEvent[type] ||(this._oneEvent[type]=[]);

    this._oneEvent[type].push(listener);
    return this;

};

PxerEvent.prototype.off =function(type, listener){

    if( !( this._checkEventType(type) && this._checkListener(listener) )) return this;

    if(type ==='*'){
        this._event ={};
        return this;
    };

    if(typeof listener ==='undefined'){
        delete this._event[type];
        return this;
    };

    let index =this._event[type].lastIndexOf(listener);
    delete this._event[index];
    return this;

};


PxerEvent.prototype._checkEventType =function(type){

    let inEvent =this.eventList.some( item => type &&(item===type) );
    if(!inEvent){
        console.warn(`PxerEvent: "${type}" is not in eventList[${this.eventList}]`);
        return false;
    };

    return true;

};

PxerEvent.prototype._checkListener =function(listener){

    if(typeof listener !=='function'){
        console.warn(`PxerEvent: "${listener}" is not a function`);
        return false;
    };

    return true;

};


PxerEvent.prototype.dispatch =function(type ,data){

    if(!this._checkEventType(type))return this;

    if( Array.isArray(this._event[type]) &&this._event[type].length!==0){
        this._event[type].forEach(function(item){
            item.call(this ,data);
        } ,this)
    };

    if( Array.isArray(this._oneEvent[type]) &&this._oneEvent[type].length!==0){
        this._oneEvent[type].forEach(function(item){
            item.call(this ,data);
        } ,this);
        delete this._oneEvent[type];
    };

    return this;

};





//测试代码
/*
class A extends PxerEvent{
    constructor(){
        super(['say']);
        this.b=2;
    }
}

var a =new A();

a.on('say' ,function(data){
    console.log(this);
    console.log(data);//kkk
    console.log(this.b);//2
});
a.one('say' ,function(data){
    console.log('one:'+data);
});
a.dispatch('say' ,'kkk');
a.say('kkk');

// 输出：*/
//     A
//     kkk
//     2
//     one:kkk
//     A
//     kkk
//     2