Using AngularJS Service to Check if User has Admin Permissions - angularjs

Question

I am building an SharePoint App using AngularJS and am attempting to define a service that retrieves if the user is an Admin or not. The service itself is successfully logging/working as expected, but I am not sure how to use this in a controller. My end goal is that when a page loads that is tied to a controller, that this service checks if they are an admin or not. From that point, I can do all sorts of magic (ex. redirect, etc.). Here is my service:
// Check if user is an admin
appServices.factory('appAdminCheck', ['$resource', 'appCurrentUserProfile', 'appAdmins', function ($resource, appCurrentUserProfile, appAdmins) {
var userAdmin = [];
appCurrentUserProfile.query(function (usercheck) {
var userID = usercheck.Id;
appAdmins.query(function (admins) {
var admins = admins.value; // Data is within an object of "value", so this pushes the server side array into the $scope array
// Foreach type, push values into types array
angular.forEach(admins, function (adminvalue, adminkey) {
if (adminvalue.Admin_x0020_NameId == userID) {
userAdmin = true;
console.log("I'm an Admin" + userAdmin);
}
});
});
});
return userAdmin;
}]);
Update: Upon closer inspection, I would like to return the array of values, but it keeps stating that the array length is 0. I am sure it is because I am not "returning" properly.
Here is my updated service:
appServices.factory('appAdminCheck', ['$resource', 'appCurrentUserProfile', 'appAdmins', function ($resource, appCurrentUserProfile, appAdmins) {
var userAdmin = [];
var checkUser = function() {
appCurrentUserProfile.query(function (usercheck) {
var userID = usercheck.Id;
appAdmins.query(function (admins) {
var admins = admins.value; // Data is within an object of "value", so this pushes the server side array into the $scope array
// Foreach type, push values into types array
angular.forEach(admins, function (adminvalue, adminkey) {
if (adminvalue.Admin_x0020_NameId == userID) {
userAdmin.push({
isAdmin: 'Yes',
role: adminvalue.Role,
});
}
});
});
});
return userAdmin;
}
return {
checkUser: checkUser
};
}]);
Here is a logging call in a controller:
var test = appAdminCheck.checkUser();
console.log(test);

Answer 1

Seeing as there appears to be some asynchronous actions happening, you'll want to return a promise. You can do this by chaining the then promise resolution callbacks from your other services (assuming they're $resource instances or similar). For example...
appServices.factory('appAdminCheck', function (appCurrentUserProfile, appAdmins) {
return function() {
return appCurrentUserProfile.query().$promise.then(function(usercheck) {
return appAdmins.query().$promise.then(function(admins) {
// this needs to change if admins.value is not an array
for (var i = 0, l = admins.value.length; i < l; i++) {
if (admins.value[i].Admin_x0020_NameId === usercheck.Id) {
return true;
}
}
return false;
});
});
};
});
Then, you can use this promise resolution in your controller, eg
appAdminCheck().then(function(isAdmin) {
// isAdmin is true or false
});