enumerate-devices/index.js

A small project to normalize browser differences for enumerating media devices

module.exports = function (cb) {
    if (typeof Promise !== 'function') {
      var err = new Error('Device enumeration not supported.');
      err.kind = 'METHOD_NOT_AVAILABLE';
      if (cb) {
          console.warn('module now uses promise based api - callback is deprecated');
          return cb(err);
      }
      throw err;
    }

    return new Promise(function(resolve, reject) {
        var processDevices = function (devices) {
            var normalizedDevices = [];
            for (var i = 0; i < devices.length; i++) {
                var device = devices[i];
                //make chrome values match spec
                var kind = device.kind || null;
                if (kind && kind.toLowerCase() === 'audio') {
                    kind = 'audioinput';
                } else if (kind && kind.toLowerCase() === 'video') {
                    kind = 'videoinput';
                }
                normalizedDevices.push({
                    facing: device.facing || null,
                    deviceId: device.id || device.deviceId || null,
                    label: device.label || null,
                    kind: kind,
                    groupId: device.groupId || null
                });
            }
            resolve(normalizedDevices);
            if (cb) {
                console.warn('module now uses promise based api - callback is deprecated');
                cb(null, normalizedDevices);
            }
        };

        if (window.navigator && window.navigator.mediaDevices && window.navigator.mediaDevices.enumerateDevices) {
            window.navigator.mediaDevices.enumerateDevices().then(processDevices);
        } else if (window.MediaStreamTrack && window.MediaStreamTrack.getSources) {
            window.MediaStreamTrack.getSources(processDevices);
        } else {
            var err = new Error('Device enumeration not supported.');
            err.kind = 'METHOD_NOT_AVAILABLE';
            reject(err);
            if (cb) {
                console.warn('module now uses promise based api - callback is deprecated');
                cb(err);
            }
        }
    });
};