JS观察者模式

观察者模式

// 观察者
var observer = {
    // 订阅集合
    subscribes: [],
    subscribe:function(type,fn){
        if (!this.subscribes[type]) {
            this.subscribes[type] = [];
        }
        typeof fn === 'function' && this.subscribes[type].push(fn);
    },

    publish:function(){
        var type = [].shift.call(arguments);
        var fns = this.subscribes[type];
        if (!fns && !fns.length) {
            return;
        }
        for (let index = 0; index < fns.length; index++) {
            fns[index].apply(this,arguments);
        }
    },

    remove:function(type,fn)
    {
        if (typeof type === 'undefined') {
            this.subscribes = [];
            return;
        }
        if (typeof fn === 'undefined') {
            fn.length = 0;
            return;
        }

        var fns = this.subscribes[type];
        if (!fns && !fns.length) {
            return;
        }
        for (let index = 0; index < fns.length; index++) {
                if (fns[index] === fn) {
                    fns.splice(index,1);
                }
        }
    }
}

// 订阅岗位列表
function jobListForA(jobs) {
    console.log('A', jobs);
}

function jobListForB(jobs) {
    console.log('B', jobs);
}

// A订阅了笔试成绩
observer.subscribe('job', jobListForA);
// B订阅了笔试成绩
observer.subscribe('job', jobListForB);


// A订阅了笔试成绩
observer.subscribe('examinationA', function(score) {
    console.log(score);
});

// B订阅了笔试成绩
observer.subscribe('examinationB', function(score) {
    console.log(score);
});

// A订阅了面试结果
observer.subscribe('interviewA', function(result) {
    console.log(result);
});

observer.publish('examinationA', 100); // 100
observer.publish('examinationB', 80); // 80
observer.publish('interviewA', '备用'); // 备用