sportsbitenews/getusermedia

Cross-browser getUserMedia shim with a node.js style error-first API

getUserMedia

What is this?

A tiny browser module that gives us a simple API for getting access to a user's camera or microphone by wrapping the navigator.getUserMedia API in modern browsers.

This is important because as of right now, all browsers return errors differently. More on that below.

This lib also gracefully handles the lack of support in a browser. So you never have to check first (see error handling below).

It gives us a cleaner node.js-style, error-first API and cross-browser handling. No browser support checking necessary, lack of support is treated in the same way as when the user rejects the request: the callback gets passed an error as the first argument.

Suitable for use with browserify/CommonJS on the client.

If you're not using browserify or you want AMD support use getusermedia.bundle.js. Note that if no module system is detected it simply attaches a function called getUserMedia to window.

Installing

npm install getusermedia

How to use it

With this helper it's clean/simple to get access to a user's camera, mic, etc.

var getUserMedia = require('getusermedia');

getUserMedia(function (err, stream) {
    // if the browser doesn't support user media
    // or the user says "no" the error gets passed
    // as the first argument.
    if (err) {
       console.log('failed');
    } else {
       console.log('got a stream', stream);  
    }
});

Passing in options is optional. It defaults to {video: true, audio: true};

// optionally pass constraints as the first argument
// they just passed through.
getUserMedia({video: true, audio: false}, function (err, stream) { ... });

Why? Because it's super ugly without this tool

// first deal with browser prefixes
var getUserMedia = navigator.getUserMedia || 
    navigator.mozGetUserMedia || 
    navigator.webkitGetUserMedia;

// make sure it's supported and bind to navigator
if (getUserMedia) {
    getUserMedia = getUserMedia.bind(navigator);
} else {
    // have to figure out how to handle the error somehow
}

// then deal with a weird, positional error handling API
getUserMedia(
    // media constraints
    {video: true, audio: true}, 
    // success callback
    function (stream) {
        // gets stream if successful
    }, 
    // error callback
    function (error) {
        // called if failed to get media
    }
)

Handling errors (summary)

All failed calls to getusermedia in this library will return an error object (of type NavigatorUserMediaError) as the first argument to the callback. All will have a .name according to the specification

License

MIT

Created By

If you like this, follow: @HenrikJoreteg on twitter.