$window.requestFileSystem($window.LocalFileSystem.PERSISTENT, 0, function(fs) {
                    console.log("fs", fs);

                    var directoryReader = fs.root.createReader();

                    directoryReader.readEntries(function(entries) {
                            var arr = [];
                            processEntries(entries, arr); // arr is pass by refrence
                            $scope.files = arr;
//                            $rootScope.hide();
                        },
                        function(error) {
                            console.log(error);
                        });
                },
                function(error) {
                    console.log(error);
                });