问发布/订阅发布后的通知

EN

            var publisher = {
            subscribers: {
                any: [] // event type: subscribers
            },
            publications: {
                any: []
            },
            subscribe: function (fn, type) {
                type = type || 'any';
                if (typeof this.subscribers[type] === "undefined") {
                    this.subscribers[type] = [];
                }

                this.subscribers[type].push(fn);

                if(typeof this.publications[type] === "undefined"){
                    return;
                }

                var pubs = this.publications[type],
                i,
                max = pubs.length

                for(i = 0;i<max;i++){
                    this.subscribers[type][i](pubs[i]);
                }

            },
            unsubscribe: function (fn, type) {
                this.visitSubscribers('unsubscribe', fn, type);
            },
            publish: function (publication, type) {
                var pubtype = type || 'any';
                this.visitSubscribers('publish', publication, type);
                if(typeof this.publications[pubtype] === "undefined") {
                    this.publications[pubtype] = [];
                }
                this.publications[pubtype].push(publication);
            },
            visitSubscribers: function (action, arg, type) {
                var pubtype = type || 'any',
                subscribers = this.subscribers[pubtype],
                i,
                max;

                if(typeof subscribers === 'undefined') {
                    return;
                }

                max = subscribers.length;

                for (i = 0; i < max; i += 1) {
                    if (action === 'publish') {
                        subscribers[i](arg);
                    } else {
                        if (subscribers[i] === arg) {
                            subscribers.splice(i, 1);
                        }
                    }
                }
            }
        };

        function makePublisher(o) {
            var i;
            for (i in publisher) {
                if (publisher.hasOwnProperty(i) && typeof publisher[i] === "function") {
                    o[i] = publisher[i];
                }
            }
            o.subscribers = {any: []};
            o.publications = {any: []};
        }

        var paper = {
            daily: function () {
                this.publish("big news today");
            },
            monthly: function () {
                this.publish("interesting analysis", "monthly");
            },
            yearly: function () {
                this.publish("every year","yearly");
            }
        };

        makePublisher(paper);

        var joe = {
            drinkCoffee: function (paper) {
                console.log('Just read ' + paper);
            },
            sundayPreNap: function (monthly) {
                console.log('About to fall asleep reading this ' + monthly);
            },
            onHolidays: function(yearly) {
                console.log('Holidays!'+yearly);
            }
        };


        paper.daily();
        paper.monthly();
        paper.yearly();

        paper.subscribe(joe.drinkCoffee);
        paper.subscribe(joe.onHolidays,'yearly');
        paper.subscribe(joe.sundayPreNap, 'monthly');