Interval Loop (Loop array with delay & callback)

IntervalLoop.js

var IntervalLoop = function (arrData, looper, delay) {
	if (!(this instanceof IntervalLoop))
		return new IntervalLoop (arrData, looper, delay);

	/**
	 * Status
	 * @type Number
	 * 0: 循环未开始
	 * 1: 正在循环
	 * 2: 循环结束
	 */
	this.status = 0;
	this.next = this._next.bind (this);
	this.index = 0;

	this.setDelay (delay || 50);
	this.data = (arrData instanceof Array) ? arrData : [];
	this.setLooper (looper);
};

IntervalLoop.prototype = {
	_getDelay: function () {
		if (!this.delay)
			return 50;

		if (this.delay.apply)
			return this.delay();

		return this.delay;
	},
	_next: function () {
		// 状态改为 进行中
		this.status = 1;
		if (this.index < this.data.length) {
			setTimeout (this.looper.bind(this, this.data[this.index]), this.delay);
			this.index ++;
		} else {
			this.status = 2;
		}
	},
	cleanup: function () {
		if (this.status == 2) {
			// 已经用过的数据就清掉。
			this.data.splice(0, this.index);
			this.index = 0;
			this.status = 0;
		}

		return this;
	},
	add: function () {
		if (arguments.length > 0) {
			// 将所有参数作为数据推入 this.data
			for (var i = 0; i<arguments.length; i++)
				this.data.push (arguments[i]);

			// 整个组已经完结，清理后自动继续
			if (this.status == 2)
				this.cleanup().next();
		}

		// 连锁
		return this;
	},
	setDelay: function (newDelay) {
		if (newDelay) this.delay = parseInt (newDelay);
		return this;
	},
	setLooper: function (fooCallback) {
		if (fooCallback && fooCallback.apply)
			this.looper = fooCallback.bind(this, this.next);

		return this;
	},
	loop: function () {
		if (this.status == 0)
			// 尚未启动, 从头开始
			this.next ();

		return this;
	}
};

// 用法:
var loop = new IntervalLoop ([1, 2, 3], function (next, item) {
	$.ajax ({
		url: 'http://example.com/?id=' + item
	}).success (function (r) {
		// TODO: 处理抓取的数据
		// ...
		
		next ();
	});
}, 500).add (1, 2, 3).add (999).loop ();

// TODO: 监听节点更新
var xyz = document.addEventListener ('xyz', function (eve) {
	// TODO: 解析数据并传递需要的值
	loop.add(eve.target);
}, false);