AngularJS – 控制器不等待条件语句中的服务返回值

我正在尝试将登录用户重定向远离登录页面,如果他们尝试在应用程序中访问它.与登录页面关联的控制器 – Login_controller调用授权服务中的函数 – Authorisation_service.isLoggedIn().如果此服务返回true,则应将用户重定向到登录的概述页面.

通过登录到控制台,我可以看到在服务返回true之前,条件语句已经声明从服务返回的值是未定义的.之后服务确实返回true,但为时已晚.

如何让控制器的条件语句等待服务的返回值？

Authorise_service.js

myApp.factory('Authorise',['User','$http','$location','$rootScope',function( User,$http,$location,$rootScope ) {
    return {
        isLoggedIn: function() {
            if( ((sessionStorage.username && sessionStorage.authKey) && (sessionStorage.username !== "null" && sessionStorage.authKey !== "null")) || ((localStorage.username && localStorage.authKey) && (localStorage.username !== "null" && localStorage.authKey !== "null" )) ) {
                if( sessionStorage.username ) {
                    var usernameLocal = sessionStorage.username;
                    var authKeyLocal = sessionStorage.authKey;
                } else {
                    var usernameLocal = localStorage.username;
                    var authKeyLocal = localStorage.authKey;
                }
                //pass to server
                var user = User.query({ usernameLocal: usernameLocal,authKeyLocal: authKeyLocal },function(user) {
                    if( user.loginSuccess === 1 ) {
                        return true;
                    } else {
                        return false;
                    }
                });
            } else {
                return false;
            }
        }
    };
}]);

Login_controller.js

myApp.controller( 'Login_controller',function( Authorise,$scope,$location ) {
    if( Authorise.isLoggedIn() === true ) {
        console.log("Authorise.isLoggedIn() = true");
        $location.path('/teach/overview');
    }
});

function myFunc() {
   var result = false;

   // You are calling async request to the server,so the execution won't wait for the
   // results. It will simply fire server request and proceed to next lines.
   serverCall(function(srvResponse){

      result = srvResponse.everythingIsGood; // This will be called after the whole method finishes!
   });

   return result; // This will MOST PROBABLY return 'false' all the times.
}

function theRealLogicYouWantToDo(result) {
   if (result) {
      // ...
   } else {
      // ...
   }
}

serverCall(function(srvResponse) {
   theRealLogicYouWantToDo(srvResposne.everythingIsGood);
});