How to check authorization at startup in Angular?

Question

Angular

Good afternoon.
Tell me how to properly implement user authentication checks at application startup? I use jwt on the backend to create a token. When I log in, I get a token and store it and data about the user in session storage, but when I close and open the browser, I need to check the authenticity of the token on the back end. I want to do this in the run block, but how can I do it so that I don't get the opportunity to work with the application until the authentication is checked? Suddenly, the user starts not from the first page, but from the "closed" one. Need something like resolve in state

Answer 1

something like this in the module's run method

function run($rootScope, auth) {
// ...
        var noAuth = ['page.login','page.404'];
        $rootScope.$on('$stateChangeStart', function (event, toState, toParams) {
            var isAuth = auth.isAuth();
            if (toState.name === 'page.login' && isAuth) {
                event.preventDefault();
                $rootScope.$state.go('app.home');
            }
            else if (!(toState.name in noAuth)  && !isAuth) {
                event.preventDefault();
                $rootScope.$state.go('page.login');
            }
        });
    };

I store jwt in local storage, it has expired, that is, you can check in the getter, if the user changed it manually, then the server will return 401

function sessionservice($localStorage) {
        var service = {
            setAccessToken: setAccessToken,
            clearAccessToken: clearAccessToken,
            getAccessToken: getAccessToken,
            getTokenInfo: getAccessTokenOpenInfo
        };

        return service;

        function setAccessToken(tokenData) {
            $localStorage.auth = tokenData;
            if ($localStorage.auth.expires_in)
                $localStorage.auth.expires_in = $localStorage.auth.expires_in * 10e3 + Date.now();
        }
        function clearAccessToken() {
            delete $localStorage.auth;
        }
        function getAccessToken() {
            if (!$localStorage.auth || !$localStorage.auth.expires_in || $localStorage.auth.expires_in < Date.now()) {
                clearAccessToken();
                return undefined;
            }
            else
                return $localStorage.auth.access_token;
        }
        function getAccessTokenOpenInfo() {
            var token = getAccessToken();
            return !token ? undefined : JSON.parse(atob(token.split('.')[1]));
        }
    }

function authinterceptor($q, $rootScope, session) {
        var request = function (config) {
            config.headers = config.headers || {};
            var token = session.getAccessToken();
            if (token) {
                config.headers.Authorization = 'Bearer ' + token;
            }
            return config || $q.when(config);
        };
        var responseError = function (rejection) {
            if (rejection.status === 401) {
                session.clearAccessToken();
                $rootScope.$state.go('page.login');
            }
            return $q.reject(rejection);
        };
        return {
            request: request,
            responseError: responseError
        };
    }