Прежде всего, вы должны проверить, чтобы URL-адрес не был пустым, используя следующую логику:
if !link.isEmpty{
checkBookFileExists(withLink: link){ [weak self] downloadedURL in
guard let self = self else{
return
}
play(url: downloadedURL)
}
}
Затем функция checkBookFileExists проверит, сохранен ли файл перед загрузкой, или нет:
func checkBookFileExists(withLink link: String, completion: @escaping ((_ filePath: URL)->Void)){
let urlString = link.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed)
if let url = URL.init(string: urlString ?? ""){
let fileManager = FileManager.default
if let documentDirectory = try? fileManager.url(for: .documentDirectory, in: .userDomainMask, appropriateFor:nil, create: false){
let filePath = documentDirectory.appendingPathComponent(url.lastPathComponent, isDirectory: false)
do {
if try filePath.checkResourceIsReachable() {
print("file exist")
completion(filePath)
} else {
print("file doesnt exist")
downloadFile(withUrl: url, andFilePath: filePath, completion: completion)
}
} catch {
print("file doesnt exist")
downloadFile(withUrl: url, andFilePath: filePath, completion: completion)
}
}else{
print("file doesnt exist")
}
}else{
print("file doesnt exist")
}
}
Тогда, если файл не существует, вы загрузите его с помощью следующей функции:
func downloadFile(withUrl url: URL, andFilePath filePath: URL, completion: @escaping ((_ filePath: URL)->Void)){
DispatchQueue.global(qos: .background).async {
do {
let data = try Data.init(contentsOf: url)
try data.write(to: filePath, options: .atomic)
print("saved at \(filePath.absoluteString)")
DispatchQueue.main.async {
completion(filePath)
}
} catch {
print("an error happened while downloading or saving the file")
}
}
}
Эта функция сохранит ее, и вы можете играть с:
func play(url: URL) {
print("playing \(url)")
do {
audioPlayer = try AVAudioPlayer(contentsOf: url)
audioPlayer?.prepareToPlay()
audioPlayer?.delegate = self
audioPlayer?.play()
let percentage = (audioPlayer?.currentTime ?? 0)/(audioPlayer?.duration ?? 0)
DispatchQueue.main.async {
// do what ever you want with that "percentage"
}
} catch let error {
audioPlayer = nil
}
}