jquery在线Ping工具

使用方法

/**
 * Creates a Ping instance.
 * @returns {Ping}
 * @constructor
 */
var Ping = function(opt) {
    this.opt = opt || {};
    this.favicon = this.opt.favicon || "/favicon.ico";
    this.timeout = this.opt.timeout || 0;
    this.logError = this.opt.logError || false;
};

/**
 * Pings source and triggers a callback when completed.
 * @param source Source of the website or server, including protocol and port.
 * @param callback Callback function to trigger when completed. Returns error and ping value.
 * @param timeout Optional number of milliseconds to wait before aborting.
 */
Ping.prototype.ping = function(source, callback) {
    var self = this;
    self.wasSuccess = false;
    self.img = new Image();
    self.img.onload = onload;
    self.img.onerror = onerror;

    var timer;
    var start = new Date();

    function onload(e) {
        self.wasSuccess = true;
        pingCheck.call(self, e);
    }

    function onerror(e) {
        self.wasSuccess = false;
        pingCheck.call(self, e);
    }

    if (self.timeout) {
        timer = setTimeout(function() {
            pingCheck.call(self, undefined);
    }, self.timeout); }


    /**
     * Times ping and triggers callback.
     */
    function pingCheck() {
        if (timer) { clearTimeout(timer); }
        var pong = new Date() - start;

        if (typeof callback === "function") {
            // When operating in timeout mode, the timeout callback doesn't pass [event] as e.
            // Notice [this] instead of [self], since .call() was used with context
            if (!this.wasSuccess) {
                if (self.logError) { console.error("error loading resource"); }
                return callback("error", pong);
            }
            return callback(null, pong);
        }
    }

    self.img.src = source + self.favicon + "?" + (+new Date()); // Trigger image load with cache buster
};

if (typeof exports !== "undefined") {
    if (typeof module !== "undefined" && module.exports) {
        module.exports = Ping;
    }
} else {
    window.Ping = Ping;
}