updating variable after ajax call made in angularjs - ajax

Question

I use factory to make database calls in angularjs
var app = angular.module('myApp', []);
app.factory("Service", function ($http) {
var obj = {};
$http.get('test.txt').then(function (data) {
obj.getApiKey = {'Authorization' : data.data};
});
return obj;
});
app.factory("Orders", function ($http, Service) {
var obj = {};
var api_key = Service.getApiKey;
console.log(api_key);
return obj;
});
In the above program, when i call property of Service factory and log the value of api_key = Service.getApiKey; it shows undefined. Probably its because the data is not received from $http call. How to perform the AJAX call synchronously.

Answer 1

var app = angular.module('myApp', []);
app.factory("Service", function ($http) {
var obj = {};
factory.get=function(success,error){
$http.get('test.txt').then(function (data) {
obj.getApiKey = {'Authorization' : data.data};
});
return obj;
}
});
app.factory("Orders", function ($http, Service) {
Service.get(suc,err);
var suc=function()
{
var obj = {};
var api_key = Service.getApiKey;
console.log(api_key);
return obj;
}
});

Answer 2

As noted by Jonathan, it's not best practice you not use synchronous calls with AJAX, instead, you can return a promisse as a funcion and use it later:
var app = angular.module('myApp', []);
app.factory("Service", function ($http) {
var obj = {};
obj.getApiKey = $http.get('test.txt').then(function (data) {
return {'Authorization' : data.data};
});
return obj;
});
app.factory("Orders", function ($http, Service) {
var obj = {};
obj.getApiKey = Service.getApiKey.then(function(data){
console.log(data);
return data;
});
return obj;
});
In this case, the service is returning a promisse object, this way you can ensure values will be called successfully and data will be available after the call.

Answer 3

Return a Promise from your service:
app.factory("Service", function ($http) {
return {
getApiKey: function() {
return $http.get('test.txt');
}
};
});
Inject your service, and use the Promise API to get your data asynchronously:
app.factory("Orders", function ($http, Service) {
var obj = {};
var api_key = {};
Service.getApiKey().then(function(apiKey) {
api_key = apiKey.data;
});
});