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[lgwebdream]

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[lgwebdream]

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[GuoLizhi]

极简版Pub/Sub

    class Publisher {
        constructor() {
            this._subs = {}
        }
        addSub(type, callback) {
            if (!this._subs[type]) {
                this._subs[type] = []
            }
            this._subs[type].push(callback)
        }
        notify(type) {
            if (!this._subs[type]) return
            const args = Array.prototype.slice.call(arguments, 1)
            this._subs[type].forEach(callback => {
                callback.call(this, args)
            })
        }
        destory(type, func) {
            this._subs[type].forEach((item, index, arr) => {
                if (item === func) {
                    arr.splice(index, 1)
                }
            })
        }
        once(type, func) {
            function onceAdd() {
                func.apply(this, arguments)
                this.destory(type, onceAdd)
            }
            this.addSub(type, onceAdd)
        }
    }