Have fun!

promises-for-the-win.js

cramo.service('Cart', function($http, $q, $localStorage) {

    var _cart = null,
        _items = null,
        self = this,
        getCart = function(userID) {
            var deferred = $q.defer();

            if(_cart) {
                deferred.resolve(_cart);
            } else {

                $http({
                    method: "GET",
                    url: api.cart.getLocal
                })
                .success(function(cart) {
                    if(cart) {
                        _cart = cart;
                        deferred.resolve(cart);
                    } else {
                        deferred.reject(new Error('Cart response was empty'));                        
                    }
                })
                .error(function() {
                    deferred.reject(new Error('Error when caling for cart'));
                });

            }

            return deferred.promise;
        },
        getItems = function() {

        var deferred = $q.defer();

        if(items) {
            deferred.resolve(items);
        } else {
            items = [];

            getCart().then(function(data) {
                for (var i = 0; i < data.length; i++) {
                    items.push(data[i].products.length);
                }

                deferred.resolve(items);
            });

        }

        getCart().then(function(data) {
            for (var i = 0; i < data.length; i++) {
                items += data[i].products.length;
            }

            return items;
            deferred.resolve(items);
        });

        return deferred.promise;
    };


    return {
        items: getItems
    };
});