browser

Why?

Why not?

You need to detect the browser, device and platform from the user agent string in many use cases. I have personally come across the following use cases:

1. You want to render different HTML for different browsers, devices or platforms.
2. You want to render OG tags for scraping bots and social media sites.
3. You want to log the browser, device or platform for your analytics.
4. You want your backend to behave differently when a Google bot crawls your site for SEO.

I wanted a relatively extensible package that I could use in all the above use cases. So, I decided to write this package.

Inspiration

The ruby gem fnando/browser inspires this package. I have used the gem in some of my previous projects and liked it. All the credit goes to the author of the ruby gem, who has done a great job.

Design

I have kept the design as similar as possible to the gem but made changes where I felt necessary per the Go.

The following are the sub-packages:

• matchers: This package defines all the browser matchers.
• devices: This package defines all the device matchers.
• platforms: This package defines all the platform matchers.
• bots: This package defines all the bots matchers.

A Matcher interface defines a matching behaviour for a user agent string.

type Matchers interface {
    Match() bool    // Match returns true if the user agent string matches the matcher.
    Name() string   // Name returns the name of the matcher.
}

Matchers

BrowserMatcher interface matches the user agent string with the browser. Implement the BrowserMatcher interface to add a new browser.

type BrowserMatcher interface {
    Matcher
    Version() string // Version returns the full version of the browser.
}

Devices

DeviceMatcher interface matches the user agent string with the device. Implement the DeviceMatcher interface to add a new device.

type DeviceMatcher interface {
    Matcher
}

Platforms

PlatformMatcher interface matches the user agent string with the platform. Implement the PlatformMatcher interface to add a new device.

type PlatformMatcher interface {
    Matcher
    Version() string // Version returns the version of the platform.
}

Bots

BotMatcher interface matches the user agent string with the bot. Implement the BotMatcher interface to add a new bot.

type BotMatcher interface {
    Matcher
}

Browser Struct

Browser struct abstracts a lot of functionality. It uses the BrowserMatcher, DeviceMatcher, PlatformMatcher and BotMatcher interfaces to match the user agent string with the browser, device, platform and bot respectively. All the matchers are executed in the order they are defined in the Browser struct. The first matcher that returns true will be used.

A ton of helper functions are defined in the Browser struct to make it easy to use.

Usage

go get github.com/dineshgowda24/browser

Browser Detection

b, err := browser.NewBrowser("Mozilla/5.0 (Linux; Android 10; SM-A205U) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.210 Mobile Safari/537.36")
 if err != nil {
  // handle error
 }

 // browser level information
 fmt.Println(b.Name())           // Chrome
 fmt.Println(b.Version())        // 90.0.4430.210
 fmt.Println(b.ShortVersion())   // 90
 fmt.Println(b.IsBrowserKnown()) // true
 fmt.Println(b.IsChrome())       // true

 // device level information
 fmt.Println(b.Device().Name())      // Samsung SM-A205U
 fmt.Println(b.Device().IsTablet())  // false
 fmt.Println(b.Device().IsSamsung()) // true

 // platform level information
 fmt.Println(b.Platform().Name())         // Android
 fmt.Println(b.Platform().Version())      // 10
 fmt.Println(b.Platform().IsAndroidApp()) // false

 // bot level information
 fmt.Println(b.Bot().Name())  // ""
 fmt.Println(b.Bot().IsBot()) // false

Bot Detection

b, err := browser.NewBrowser("APIs-Google (https://developers.google.com/webmasters/APIs-Google.html)")
if err != nil {
   // handle error
}

// browser level information
fmt.Println(b.Name())           // Unknown Browser
fmt.Println(b.Version())        // 0.0
fmt.Println(b.ShortVersion())   // 0
fmt.Println(b.IsBrowserKnown()) // false
fmt.Println(b.IsUnknown())      // true

// bot level information
fmt.Println(b.Bot().Name())  // "APIs-Google"
fmt.Println(b.Bot().IsBot()) // true
fmt.Println(b.Bot().Why())   // *bots.Known

Contributing

If you want to contribute to this project, please read the CONTRIBUTING.md file.

Issues

If you find any issues with this package, please raise an issue. I will fix it as soon as possible. Please read the Contributing section if you want to resolve the issue and contribute.

License

This project is licensed under the MIT License - see the LICENSE file for details.