Wait for multiple Alamofire request - ios

Question

I'm trying to add data to my data model so to test it I'm printing the info fetched via Alamofire but my problem is since some data needs to call the api again it becomes null when I print it. Here's my code
Code for getting the person's data
func printAPI(){
swApiHandler.requestSWPApi("http://swapi.co/api/people", completionHandler: {(response, error) in
let json = JSON(response!)
let jsonResult = json["results"]
for (index,person):(String, JSON) in jsonResult{
let name = person["name"].stringValue
let height = person["height"].intValue
let mass = person["mass"].intValue
let hairColor = person["hair_color"].stringValue
let skinColor = person["skin_color"].stringValue
let eyeColor = person["eye_color"].stringValue
let birthYear = person["birth_year"].stringValue
let gender = person["gender"].stringValue
let homeWorldUrl = person["homeworld"].stringValue
let homeWorldNameKey = "name"
let homeWorld = self.getSWApiSpecificValue(homeWorldUrl, strKey: homeWorldNameKey)
print("Name: \(name)")
print("Height: \(height)")
print("Mass: \(mass)")
print("Hair Color: \(hairColor)")
print("Skin Color: \(skinColor)")
print("Eye Color: \(eyeColor)")
print("Birth Year: \(birthYear)")
print("Gender: \(gender)")
print("Home World: \(homeWorld)")
print("------------------------------")
}
})
}
Code for getting the specific value
func getSWApiSpecificValue(strUrl: String, strKey: String) -> String{
var name = ""
swApiHandler.requestSWPApi(strUrl, completionHandler: {(response,error) in
let json = JSON(response!)
print(json[strKey].stringValue)
name = json[strKey].stringValue
})
return name
}
If you want to know the JSON Model here it is
And for running the code here's the output

Answer 1

You should make your api call in background and after it's finished populate your data on main queue.
Just change your code to get specific value to this one:
func getSWApiSpecificValue(strUrl: String, strKey: String) -> String{
var name = ""
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)) { () -> Void in
swApiHandler.requestSWPApi(strUrl, completionHandler: {(response,error) in
dispatch_async(dispatch_get_main_queue()) {
let json = JSON(response!)
print(json[strKey].stringValue)
name = json[strKey].stringValue
return name
}
})
}
}
In code above first you get make a request to the server in background and if you get response in main queue will populate you variable name.
Also it's better to change your api call function to something like that:
func getDataFromServer(ulr: String, success: (([AnyObject]) -> Void)?, failure: (error: ErrorType) -> Void){
}
In this way you can handle your errors and if success get your data.