Basic service exposing a $resource in angular

service.js

(function () {

    // @ngInject
    function Book($resource){
        var resource = $resource('/api/books/:id', {id: '@id'}, {
            update: {method: 'PUT'},
            subscribe: {method: 'GET', id: '@id', url: '/api/books/:id/subscribe'},
        });

        return {
            query: function() {
                return resource.query().$promise;
            },
            get: function(id) {
                return resource.get({id: id}).$promise;
            },
            save: function(data) {
                return resource.save(data).$promise;
            },
            update: function(data) {
                return resource.update(data).$promise;
            },
            delete: function(id) {
                return resource.delete({id: id}).$promise;
            },
            subscribe: function(id) {
                return resource.subscribe({id: id}).$promise
            }
        };
    }

    angular
        .module('app')
        .service('Book', Book)

})();