Ping.js

Ping.js is a small and simple Javascript library for the browser to “ping” response times to web servers in Javascript! This is useful for when you want to display realtime ping times on a status page which are relative to the user.

See Notes below for how this works.

JS Fiddle Example: http://jsfiddle.net/alfg/sr0tpn4x/

Example in jQuery: http://jsfiddle.net/alfg/xjqbvt2o/

Usage

This module is for the browser only as it depends on the brower’s Image API.

Download the distribution files in dist to your project.

var p = new Ping();
// Using callback
p.ping("https://github.com", function(err, data) {
  // Also display error if err is returned.
  if (err) {
    console.log("error loading resource")
    data = data + " " + err;
  }
  document.getElementById("ping-github").innerHTML = data;
});
// You may use Promise if the browser supports ES6
p.ping("https://github.com")
  .then(data => {
    console.log("Successful ping: " + data);
  })
  .catch(data => {
    console.error("Ping failed: " + data);
  })

or import as a module:

$ npm install ping.js

import Ping from 'ping.js';

or use the jsdelivr CDN:

<script src="https://cdn.jsdelivr.net/gh/alfg/ping.js@0.2.2/dist/ping.min.js" type="text/javascript"></script>

See demo/react-example for an example in React.

API

var p = new Ping(opt);

Ping([options])

Create Ping instance.

`options`

Type: Object
favicon: Override the default favicon.ico image location.
timeout: Optional - Set a timeout in milliseconds.

p.ping(source, callback)

Creates a ping request to the source. Returns a promise that resolves and rejects to the response time in milliseconds, or if the browser does not supports Promise, returns undefined.

source: IP address or website URL, including protocol and port (optional). Example: https://example.com:8080
callback(err, ping): Optional - Callback function which returns an error and the response time in milliseconds.

Development

Install project:

git clone https://github.com/alfg/ping.js.git
cd ping.js
npm install
npm install -g grunt-cli

Run grunt to build distribution files:

grunt

Open demo/index.html in a browser to test results.

Notes

Javascript itself doesn’t have a native way of sending a “ping”, so results may not be completely accurate. Since xhr requests are affected by cross-domain issues (CORS), they are blocked by default. ping.js is using a method of loading a favicon.ico image from any host and timing the response time. If the favicon image doesn’t exist, an error is returned along with the ping value. If there’s a better way to do this in Javascript, feel free to create an issue, or pull request so I can review.