Q.all.then doesn't wait for completion - angularjs

Question

I have a service in separate JS file, this service is like OOP class that holds 'methods' to load necessary data from the web.
I want call those 'methods' and get the data in my main JS file, actually I want to load data of three types and force JS flow to wait untill that data is retrieved, here's my code:
services.js
// My 'Class' to load data from the web server
myApp.factory("LoadData", ["_gl", function (_gl) {
return {
GetUsers: function ($http) {
$http({
method: 'POST',
url: 'http://localhost/dgis/ps/select.php',
data: { "action": "GetUsers" }
}).then(function successCallback(response) {
// Save the response JSON object to my global objects
_gl.myUsers = response.data;
}, function errorCallback(response) {
console.log("GetUsersError:" + response);
});
},
GetObGroups: function ($http) {
$http({
method: 'POST',
url: 'http://localhost/dgis/ps/select.php',
data: { "action": "GetObGroups" }
}).then(function successCallback(response) {
// Save the response JSON object to my global objects
// This code fills array because it iterates through it
angular.forEach(response.data, function (value, key) {
_gl.myObGroups.push(value)
});
}, function errorCallback(response) {
console.log("GetObGroups:" + response);
});
},
GetObjects: function ($http) {
$http({
method: 'POST',
url: 'http://localhost/dgis/ps/select.php',
data: { "action": "GetObjects" }
}).then(function successCallback(response) {
_gl.myObjects = response.data;
}, function errorCallback(response) {
console.log("GetObjectsError:" + response);
});
}
}
}]);
// My global variables
myApp.factory('_gl', function () {
return {
myUsers: [],
myOrganisations: [],
myObGroups: [],
myObjects: []
}
});
script.js
Q.all([LoadData.GetUsers($http), LoadData.GetObGroups($http), LoadData.GetObjects($http)]).then(function () {
console.log(_gl.myUsers);
console.log(_gl.myObGroups);
console.log(_gl.myObjects);
});
The problem is, the Q.all won't wait till all http request will get the data, it evaluates calls in then before it happens. Sure, I could use some timer and just wait for a second, but I want more proper way to do that, please share with your knowledge.
And one more thing, if I use forEach in then of my get methods then arrays filling all right, but other arrays are empty and I want to know why it happens.
Thank you.

Answer 1

You have to return the promises in GetUsers, GetObGroups and GetObjects, otherwise Q.all can't do its job.
Therefore, e.g.:
GetUsers: function ($http) {
return $http({
....
should do the trick.