refactoring Camera.checkAlreadyCaptured

Author: Connormiha

lib/FileAPI.Camera.js

@@ -210,37 +210,33 @@
 };
 
 Camera.checkAlreadyCaptured = (function () {
-var enumerateDevices;
+var mediaDevices = navigator.mediaDevices,
+MediaStreamTrack = window.MediaStreamTrack,
+navigatorEnumerateDevices = navigator.enumerateDevices,
+enumerateDevices;
 
-if (navigator.mediaDevices && navigator.mediaDevices.enumerateDevices) {
+if (mediaDevices && mediaDevices.enumerateDevices) {
 enumerateDevices = function (callback) {
-navigator.mediaDevices.enumerateDevices().then(callback);
+mediaDevices.enumerateDevices().then(callback);
 };
-} else if (!enumerateDevices && window.MediaStreamTrack && window.MediaStreamTrack.getSources) {
-enumerateDevices = window.MediaStreamTrack.getSources.bind(window.MediaStreamTrack);
-} else if (!enumerateDevices && navigator.enumerateDevices) {
-enumerateDevices = enumerateDevices.bind(navigator);
+} else if (MediaStreamTrack && MediaStreamTrack.getSources) {
+enumerateDevices = MediaStreamTrack.getSources.bind(MediaStreamTrack);
+} else if (navigatorEnumerateDevices) {
+enumerateDevices = navigatorEnumerateDevices.bind(navigator);
 }
 
 return function (callback) {
 if (!enumerateDevices) {
-callback && callback(false);
+callback(false);
 return;
 }
 
 enumerateDevices(function (devices) {
-var device;
+var deviceExists = devices.some(function (device) {
+return (device.kind === 'videoinput' || device.kind === 'video') && device.label;
+});
 
-for (var i = 0; i < devices.length; i++) {
-device = devices[i];
-
-if ((device.kind === 'videoinput' || device.kind === 'video') && device.label) {
-callback && callback(true);
-return;
-}
-}
-
-callback && callback(false);
+callback(deviceExists);
 });
 };