Getting values from Facebook FBSDK iOS 4.x (with Swift)? - ios

Question

How do I make all of the functions wait for a little before they access the facebookData variable? Since the network call is asynchronous, facebookData is being accessed before it is getting the values from the Facebook.
Please find the below code from information.
func graphRequestToReturnUserData(graphParameters: Dictionary<String, String>) {
let graphRequest : FBSDKGraphRequest = FBSDKGraphRequest(graphPath: "me", parameters: graphParameters)
graphRequest.startWithCompletionHandler({ (connection, result, error) -> Void in
if ((error) != nil) {
print("Error: \(error.localizedDescription)") /*Error Handling*/
}else {
self.facebookData = result as! NSDictionary
}
})
}
I don't want to invoke the function like this :-
if ((error) != nil) {
print("Error: \(error.localizedDescription)") /*Error Handling*/
}else {
self.facebookData = result as! NSDictionary
self.printFacebookData()
}
})
}
func printFacebookData() {
print(self.facebookData)
}

Answer 1

Since I have found a solution that is working good in my situation, I am going to post it here for more to read, and possibly comment on it to improve further.
The simple solution here would be to use the property observer and call a function soon the property is changed. No need to mess up with the threads, or use of semaphores.
The solution code now looks like this: -
class facebookGraphRequest {
static var facebookData = NSDictionary()
//Property Observer, willSet-didSet
var facebookD = NSDictionary() {
didSet {
facebookGraphRequest.facebookData = facebookD //Assigning values to the static class variable
facebookUserSignUpLogIn().checkUserExistsOrNot() //Calling a function from the other class
}
}
//Mark: GraphRequestForFetchingUserData
func graphRequestToReturnUserData(graphParameters: Dictionary<String, String>) {
let graphRequest : FBSDKGraphRequest = FBSDKGraphRequest(graphPath: "me", parameters: graphParameters)
graphRequest.startWithCompletionHandler({ (connection, result, error) -> Void in
if ((error) != nil) {
print("Error: \(error.localizedDescription)") //Error Handling
} else {
self.facebookD = result as! NSDictionary
}
})
}
}
Here, the first part is the property observer (willSet-didSet), and then the GraphAPI call for getting the user data. Soon the facebookD variable is set to a value; the function checkUserExistsOrNot() is called from the class facebookUserSignUpLogIn for further actions.