promise for modal action

modalService.js

(function (angular) {
    'use strict';

    angular.module('app').factory('modalService', function ($uibModal) {
        var opened = false;
        var successCallback, errorCallback, finallyCallback;

        var thenFunction = function (success, error) {
            successCallback = success;
            errorCallback = error;
            return {
                finally: finallyFunction
            };
        };

        var finallyFunction = function (response) {
            finallyCallback = response;
            opened = false;
            return {
                then: thenFunction
            };
        };

        var getSuccessCallback = function () {
            if (angular.isFunction(successCallback)) {
                successCallback();
            }
        };

        var getErrorCallback = function () {
            if (angular.isFunction(errorCallback)) {
                errorCallback();
            }
        };

        var getFinallyCallback = function () {
            if (angular.isFunction(finallyCallback)) {
                finallyCallback();
            }
        };

        function open(params) {
            if (!opened) {
                opened = true;
                $uibModal.open(params).result.then(getSuccessCallback, getErrorCallback).finally(function () {
                    opened = false;
                    getFinallyCallback();
                });
            }
            return {
                then: thenFunction,
                finally: finallyFunction
            };
        }

        return {
            open: open
        };
    });
})(angular);