express-useragent

What is express-useragent?

The express-useragent npm package is a middleware for Express.js that allows you to parse the user-agent header to identify the user's browser, operating system, and device type. This can be useful for tailoring responses based on the client's environment.

What are express-useragent's main functionalities?

Detect Browser

This feature allows you to detect the browser being used by the client. The code sample demonstrates how to set up an Express.js server that responds with the client's browser name.

const express = require('express');
const useragent = require('express-useragent');
const app = express();

app.use(useragent.express());

app.get('/', (req, res) => {
  res.send(`You are using ${req.useragent.browser}`);
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

Detect Operating System

This feature allows you to detect the operating system of the client. The code sample shows how to set up an Express.js server that responds with the client's operating system.

const express = require('express');
const useragent = require('express-useragent');
const app = express();

app.use(useragent.express());

app.get('/', (req, res) => {
  res.send(`You are using ${req.useragent.os}`);
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

Detect Device Type

This feature allows you to detect whether the client is using a mobile or desktop device. The code sample demonstrates how to set up an Express.js server that responds with the type of device being used.

const express = require('express');
const useragent = require('express-useragent');
const app = express();

app.use(useragent.express());

app.get('/', (req, res) => {
  res.send(`You are using a ${req.useragent.isMobile ? 'mobile' : 'desktop'} device`);
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

Other packages similar to express-useragent

useragent

The useragent package is a standalone library for parsing user-agent strings. It provides similar functionality to express-useragent but is not specifically designed for use with Express.js. It can be used in any Node.js application to parse user-agent strings and extract information about the client's browser, operating system, and device.

ua-parser-js

The ua-parser-js package is a JavaScript library for parsing user-agent strings. It provides detailed information about the client's browser, operating system, and device. Unlike express-useragent, it is not tied to Express.js and can be used in both client-side and server-side JavaScript applications.

detect-browser

The detect-browser package is a lightweight library for detecting the client's browser and version. It is less comprehensive than express-useragent but can be useful for simple use cases where only browser detection is needed. It can be used in both Node.js and browser environments.

README

Middleware exposing user-agent for ExpressJS

express-useragent is a simple ExpressJS user-agent middleware exposing user-agent details to your application and views.

Installation

Installation is done using the Node Package Manager (npm). If you don't have npm installed on your system you can download it from npmjs.org To install express-useragent:

$ npm install -g express-useragent

Usage overview

Simple

var http = require('http')
  , useragent = require('express-useragent');

var srv = http.createServer(function (req, res) {
  var source = req.headers['user-agent'],
  ua = useragent.parse(source);
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end(JSON.stringify(ua));
});

srv.listen(3000);

for Express

var express = require('express')
  , app = express.createServer()
  , useragent = require('express-useragent');

app.use(useragent.express());
app.get('/', function(req, res){
    res.send(req.useragent);
});
app.listen(3000);

module provides details such as the following:

{
  "isMobile":false,
  "isDesktop":true,
  .....
  "Browser":"Chrome",
  "Version":"17.0.963.79",
  "OS":"Windows 7",
  "Platform":"Microsoft Windows",
  "source":"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.79 Safari/535.11"
}

Accessing the User-Agent

If you are using express or connect, then express-useragent provides an easy way to access the user-agent as:

• req.useragent from your app server
• useragent helper accessible from your express views.

In the Wild

The following projects use express-useragent.

If you are using express-useragent in a project, app, or module, get on the list below by getting in touch or submitting a pull request with changes to the README.

Startups & Apps

• TViMama
• GorkaTV

Author

Aleksej Gordejev ([e-mail]).

License

(The MIT License)

Copyright (c) 2012 Aleksej Gordejev [e-mail]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Resources

• Visit the author website.
• Follow @biggora on Twitter for updates.
• Report issues on the github issues page.