Wait for Swift function to finish
I have a function to get data from json and I add all data to an array. I am trying to create a semaphore and wait for the signal to be sent to the semaphore to continue, but it doesn't work (I'm not sure if I am doing this correctly or not), then I saw a question on Stackoverflow, the answer was a completion handler like this
func application(application: UIApplication!, performFetchWithCompletionHandler completionHandler: ((UIBackgroundFetchResult) -> Void)!) {
getUrunGrup(completionHandler)
}
so i changed my function like this
func getUrunGrup(completionHandler: ((UIBackgroundFetchResult) -> Void)!){
Alamofire.request(.GET, "http://213.136.86.160:27701/Thunder/DataService/GetUrunGrup")
.responseJSON {(request, response, jsonObj, error) in
if let jsonresult:NSDictionary = jsonObj as? NSDictionary{
if let result: AnyObject = jsonresult["Result"] {
let elementCount = result.count
for (var i = 0; i<elementCount; ++i){
if let name: AnyObject = result[i]["Adi"]!{
if let kod:AnyObject = result[i]["Kod"]!{
urunUstGrup.append(["Adi": "\(name)", "Kod": "\(kod)"])
println("getUrunGrup \(i)")
}
}
}
}
}
}
completionHandler(UIBackgroundFetchResult.NewData)
println("Background Fetch Complete")
}
But there is no answer, how can I call this function?
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1 answer
you need to pass your async call function to a handler to call later, like:
func application(application: UIApplication!, performFetchWithCompletionHandler completionHandler: ((UIBackgroundFetchResult) -> Void)!) {
loadShows(completionHandler)
}
func loadShows(completionHandler: ((UIBackgroundFetchResult) -> Void)!) {
//....
//DO IT
//....
completionHandler(UIBackgroundFetchResult.NewData)
println("Background Fetch Complete")
}
OR (cleaner way IMHO)
add intermediate completionHandler
func application(application: UIApplication!, performFetchWithCompletionHandler completionHandler: ((UIBackgroundFetchResult) -> Void)!) {
loadShows() {
completionHandler(UIBackgroundFetchResult.NewData)
println("Background Fetch Complete")
}
}
func loadShows(completionHandler: (() -> Void)!) {
//....
//DO IT
//....
completionHandler()
}
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