PollAjax

PollAjax.js

/**
 * 轮询ajax请求
 * @param fn
 * @param [delay = 500]
 * @constructor
 * @example
 *  var pa = new PollAjax(function (continueNext, done) {
        $.get('../')
            .done(function (data) {
                if (data.success) {
                   done();
                }
            })
            .always(function () {
                continueNext();
            });
    }, 1000);
 pa.start(5, cb);
 pa.always(cb);
 */
function PollAjax (fn, delay) {
    this.finish = false;
    this.progress = false;
    this.delay = delay || 500;
    this.fns = [];

    this.fn = fn;
}

/**
 * 次数
 * @param time
 * @param cb 完成后的回调
 */
PollAjax.prototype.start = function (time, cb) {
    var that = this;

    for (var i = 0; i < time; i++) {
        that.fns.push(that.fn);
    }

    that.next();
    that.cb = cb;
};

/**
 * 手动触发的完成
 */
PollAjax.prototype.done = function () {
    this.progress = false;
    this.finish = true;
    this.fns = [];

    if(this.cb) this.cb();
};

/**
 * 继续下一个fn
 */
PollAjax.prototype.continueNext = function () {
    var that = this;
    that.progress = false;

    if(that.fns.length) {
        that.next();
    } else {
        if(that.alwaysCB) that.alwaysCB();
    }
};

/**
 * 队列结束时的回调
 * @param [cb]
 */
PollAjax.prototype.always = function (cb) {
    this.alwaysCB = cb;
};

/**
 * 执行下一个fn
 */
PollAjax.prototype.next = function () {
    var that = this;

    if(!that.progress & !that.finish && that.fns.length != 0) {
        that.progress = true;

        setTimeout(function () {
            (that.fns.pop())(that.continueNext.bind(that),that.done.bind(that));
        }, that.delay);
    }
};