为什么我收到TypeError：onSuccess不是我的angularjs服务中的函数

Question

I have an angularjs services that leverages restangular to make calls.

angular.module('app.userSvc', [])
    .factory('userSvc', ['localStorageService', '$rootScope', 'Restangular',
        function(localStorageService, $rootScope, Restangular) {
            function checkIfLoggedIn() {
                return localStorage.getItem('token');
            }

            function login(email, password, onSuccess, onError) {
                Restangular.all('api/authenticate')
                    .post({
                        email: email,
                        password: password
                    })
                    .then(
                        function(response) {
                            localStorage.setItem('token', response.token);
                            onSuccess(response);
                        },
                        function(response) {
                            onError(response);
                        });
            }

            function logout() {
                localStorageService.remove('token');
            }

            function getCurrentToken() {
                return localStorage.getItem('token');
            }

            function getAuthenticatedUser(onSuccess, onError) {
                Restangular.one('api/authenticated_user?token=' + getCurrentToken()).get().then(function(response) {
                    onSuccess(response.user);
                }, function(response) {
                    onError(response);
                });
            }
            Restangular.setDefaultHeaders({
                'Authorization': 'Bearer ' + getCurrentToken()
            });
            return {
                checkIfLoggedIn: checkIfLoggedIn,
                login: login,
                logout: logout,
                getCurrentToken: getCurrentToken,
                getAuthenticatedUser: getAuthenticatedUser
            };
        }
    ]);

But when i call the userSvc.getAuthenticatedUser() method in a controller i get TypeError: onSuccess is not a function This is how am calling it.

console.log(userSvc.getAuthenticatedUser());

What am i doing wrong. I am using angular 1.6

Answer 1

You HAVE to set a callback function as the first argument, because inside getAuthenticatedUser() , there is no check to see whether the onSuccess argument is set or not. (The same is actually true for the onError callback, so you need to provide that second argument, too)

So, either implement such a check (eg onSuccess && onSuccess() ) inside the getAuthenticatedUser function, or provide a callback function (even if it's an anonymous one that doesn't to anything) in order to prevent that error.

userSvc.getAuthenticatedUser(function() {}, function() {});

Answer 2

Error is expected, As your service method expected callback method so pass them

function getAuthenticatedUser(onSuccess, onError){
}

So you need to pass the callback methods

userSvc.getAuthenticatedUser(function() {}, function() {})

---

Or, You can check whether argument is defined and a angular.isFunction

function getAuthenticatedUser(onSuccess, onError) {
    Restangular.one('api/authenticated_user?token=' + getCurrentToken()).get().then(function (response) {
        !!onSuccess && angular.isFunction(onSuccess) && onSuccess(response.user);
    }, function (response) {
        !!onError && angular.isFunction(onError) &&
        onError(response);
    });
}