Cordova - Angular app - Exit app clicking back button if there is no history back

cordova.exitApp.js

//  FACTORY ____________________________________________________________________________________________________________
/**
 @ngdoc              factory
 @name               cordova.factory:cordovaExitApp

 @description        Adds events to exit app on Android
 http://stackoverflow.com/questions/18184497/backbutton-confirm-exit-app-android-phonegap-jquery

 */
//  DEFINITION _________________________________________________________________________________________________________

    function cordovaExitApp($window) {

        var self = this;


        this.onBackKeyDown = function(e) {
            //e.preventDefault();

            // if there's no history back
            if (parseInt($window.history.length) <= 2 ) {
                // Prompt the user with the choice
                //navigator.notification.confirm("¿Seguro que quieres salir de sportmaniacs?", self.onConfirm, "Salir", "Sí,No");
                navigator.app.exitApp();
            } else {
                $window.history.back();
            }

        };
        this.init = function() {
            document.addEventListener("backbutton", self.onBackKeyDown, false); //Listen to the User clicking on the back button
        };

        this.onConfirm = function(button) {
            if(button ===2 ) {
                //If User selected No, then we just do nothing
                return;
            }else {
                // Otherwise we quit the app.
                navigator.app.exitApp();
            }
        };

        return {
            init: self.init
        };

    }

//  MODULE ASSIGNEMENT _________________________________________________________________________________________________

    angular.module('cordova')
        .factory('cordovaExitApp', cordovaExitApp);