ua-supports

check if a range of user agents supports a feature

Installation

$ npm install ua-supports

Usage

ua(useragents?: String) => (Feature) => Boolean

Given a user agent string, returns a function that can check against features if that user agent supports that feature or not.

The feature is just a hash of key => value pairs, where the key is the browser and the value is the lowest version of the browser that supports the feature to be tested.

See the following list of browser identifiers:

// The lowest version of the browser supporting this feature
MinimumVersion: String | Number
 
Feature: {
    ie?:      MinimumVersion,
    firefox?: MinimumVersion,
    chrome?:  MinimumVersion,
    safari?:  MinimumVersion,
    opera?:   MinimumVersion,
    ios_saf?: MinimumVersion,
    op_mini?: MinimumVersion,
    android?: MinimumVersion,
    op_mob?:  MinimumVersion,
    bb?:      MinimumVersion,
    and_chr?: MinimumVersion,
    and_ff?:  MinimumVersion,
    ie_mob?:  MinimumVersion
}

useragents

The useragents string can be either a standard useragent identifier as found in the User-Agent header, or a comma separated list of browser identifiers, with or without versions, or special expressions like last X versions. The syntax is very much like the one used by autoprefixer. If no version is given, it will default to last 2 versions of major browsers.

Example

var supports = ua('Mozilla/5.0 (X11; Linux x86_64; rv:34.0) Gecko/20100101 Firefox/34.0');
 
supports({
    firefox: 34 // feature requires ff 34
}); // => true
 
// with 2 browsers
supports = ua('chrome, firefox');
 
supports({
    firefox: 24 // the feature is only available in firefox, not in chrome
}); // => false

License

LGPLv3