用javascript实现一个 Subscribe/Publish 模式?

用javascript实现一个 Subscribe/Publish 模式,有什么特别的思路没有

阅读 4.2k
2 个回答

这是一个简单的观察者模式的JS代码:

var Observer = (function(){
    var __message = {};
    return {
        //注册信息接口
        regist : function(type, fn) {
            if (typeof __message[type] === 'undefined') {
                __message[type] = [fn];
            }else{
                __message[type].push(fn);
            }
        },
        //发布信息接口
        fire : function(type, args){
            if (!__message[type]) {
                return;
            }
            var events = {
                type : type,
                args :args || {}
            },
            i = 0;
            len = __message[type].length;
            for(; i < len; i++){
                __message[type][i].call(this, events);
            }

        },
        //移除信息接口
        remove : function(type, fn){
            if(__message[type] instanceof Array){
                var i = __message[type].length - 1;
                for (; i >= 0; i--)    {
                    __message[type][i] === fn && __message[type].splice(i,1);
                }    
            }
        }
    }
})();


var Student = function(result) {
    var that = this;
    that.result = result;
    that.say = function(){
        console.log(that.result);
    }
};
Student.prototype.answer = function(question){
    Observer.regist(question,this.say);
}
Student.prototype.sleep = function(question){
    console.log(this.result + "" + question + "已被注销")
    Observer.remove(question, this.say)
}

var Teacher = function(){};
Teacher.prototype.ask = function(question){
    console.log('问题是:' + question);
    Observer.fire(question);
}
var student1 = new Student('学生1回答问题');
var student2 = new Student('学生2回答问题');
var student3 = new Student('学生3回答问题');

student1.answer('什么是设计模式');
student1.answer('简述观察者模式');
student2.answer('什么是设计模式');
student3.answer('什么是设计模式');
student3.answer('简述观察者模式');

student3.sleep('简述观察者模式');
var teacher = new Teacher();
teacher.ask('什么是设计模式');
teacher.ask('简述观察者模式');
撰写回答
你尚未登录,登录后可以
  • 和开发者交流问题的细节
  • 关注并接收问题和回答的更新提醒
  • 参与内容的编辑和改进,让解决方法与时俱进
推荐问题