index-browser.js

// getUserMedia helper by @HenrikJoreteg
var func = (window.navigator.getUserMedia ||
            window.navigator.webkitGetUserMedia ||
            window.navigator.mozGetUserMedia ||
            window.navigator.msGetUserMedia);


module.exports = function (constraints, cb) {
    var options;
    var haveOpts = arguments.length === 2;
    var defaultOpts = {video: true, audio: true};
    var error;
    var denied = 'PermissionDeniedError';
    var notSatified = 'ConstraintNotSatisfiedError';

    // make constraints optional
    if (!haveOpts) {
        cb = constraints;
        constraints = defaultOpts;
    }

    // treat lack of browser support like an error
    if (!func) {
        // throw proper error per spec
        error = new Error('MediaStreamError');
        error.name = 'NotSupportedError';
        return cb(error);
    }

    if (localStorage && localStorage.useFirefoxFakeDevice === "true") {
        constraints.fake = true;
    }

    func.call(window.navigator, constraints, function (stream) {
        cb(null, stream);
    }, function (err) {
        var error;
        // coerce into an error object since FF gives us a string
        // there are only two valid names according to the spec
        // we coerce all non-denied to "constraint not satisfied".
        if (typeof err === 'string') {
            error = new Error('MediaStreamError');
            if (err === denied) {
                error.name = denied;
            } else {
                error.name = notSatified;
            }
        } else {
            // if we get an error object make sure '.name' property is set
            // according to spec: http://dev.w3.org/2011/webrtc/editor/getusermedia.html#navigatorusermediaerror-and-navigatorusermediaerrorcallback
            error = err;
            if (!error.name) {
                // this is likely chrome which
                // sets a property called "ERROR_DENIED" on the error object
                // if so we make sure to set a name
                if (error[denied]) {
                    err.name = denied;
                } else {
                    err.name = notSatified;
                }
            }
        }

        cb(error);
    });
};