timer code

gistfile1.js

        Timer.prototype.start = function() {
            var self = this;
            (function countdown() {
                if (self.count > 0) {
                    var m = Math.floor(self.count / 60);
                    var s = self.count % 60;
                    self.onTick(formatTime(m),formatTime(s));
                    self.count = self.count - 1;
                    $timeout(countdown, 1000);
                }
                else {
                    self.onComplete(self.tickedAtLeastOnce);
                }
            })();
        };