XMLHttpRequest中止

Question

我正在创建包含XMLHttpRequest的小函数。我需要实现abort，error和timeout处理程序，但是当我调用request.abort（）时;它被处理为超时或错误，我需要以某种方式区分这些条件，我该怎么做？

编辑：

Request = (function () {
    var call;

    function Request(args) {
        if (!(this instanceof Request)) {
            return new Request(args);
        }

        call = new XMLHttpRequest();

        args.async = args.async || true;
        args.method = args.method || 'GET';

        call.open(args.method, args.url, args.async);

        if (args.async) {
            call.timeout = args.timeout || call.timeout;
        }

        call.onreadystatechange = function () {
            if (call.readyState === 4 && call.status === 200) {
                return args.success && args.success(call.responseText, call);
            }
            //I tried with "readyState === 0" but result was the same
            if (call.readyState === 4 && call.status !== 200) {
                return args.error && args.error(call);
                //here error is callback that passed call for furher handling
                //next I should check "call" object to see if was aborted or true error or timeout
            }
        };

        try {
            return call.send();
        } catch (error) {
            return args.error(call.responseText, call);
        }
    }

    Request.prototype.abort = function () {
        return call.abort();
    };

    return Request;
}());