FileManager cannot find audio file - ios

Question

Helloo! My ultimate goal is to create a UITableViewController with recordings made in-app, using FileManager to traverse the /Documents/ directory and list all the recordings found there.
The recording and playback are functioning just fine with one recording, with the following setup:
// In VC#1
func setupRecorder(){
let audioSession:AVAudioSession = AVAudioSession.sharedInstance()
do {
try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord)
} catch {
print("Audio Setup Error: \(error)")
}
do {
try audioSession.setActive(true)
} catch {
print("Audio Setup Error: \(error)")
}
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
audioFileName = "test.caf"
audioFileUrl = documentsDirectory.appendingPathComponent(audioFileName)
print("\n\nrecording url :\(audioFileUrl.absoluteString)\n\n")
let recordSettings = [
AVFormatIDKey: Int(kAudioFormatAppleLossless),
AVEncoderAudioQualityKey : AVAudioQuality.max.rawValue,
AVEncoderBitRateKey : 320000,
AVNumberOfChannelsKey: 2,
AVSampleRateKey : 44100.0
] as [String : Any]
do {
audioRecorder = try AVAudioRecorder(url: audioFileUrl, settings: recordSettings)
} catch let error as NSError{
print("Audio Setup Error: \(error)")
audioRecorder = nil
}
audioRecorder.delegate = self
audioRecorder.isMeteringEnabled = true
audioRecorder.prepareToRecord()
}
...
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == GraphViewController.getEntrySegue() {
let navController = segue.destination as! UINavigationController
let destination = navController.topViewController as! GraphViewController
destination.audioFileName = audioFileName
destination.audioFileUrl = audioFileUrl
}
// In VC#2
func setupAudioPlayer() {
do {
try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)
} catch {
print(error)
}
do {
try AVAudioSession.sharedInstance().setActive(true)
} catch {
print(error)
}
do {
audioPlayer = try AVAudioPlayer(contentsOf: audioFileUrl)
} catch {
print("Audio Player Setup Error: \(error)")
}
audioPlayer.prepareToPlay()
}
This is working all fine and dandy; it plays the recorded audio file with no problems whatsoever. However, when I try to find the file via FileManager, FileManager cannot find it. Listed below are my attempts to find this file.
print("\(FileManager.default.fileExists(atPath: audioFileUrl.absoluteString))") // -> False
print("\(FileManager.default.contents(atPath: audioFileUrl.absoluteString))") // -> nil
Clearly I must be missing something... especially given AVAudioPlayer is successfully reading the audio file with the exact same url. The path prints as:
file:///var/mobile/Containers/Data/Application/1DA6BD0F-5A23-4228-92A9-A083E55ACE21/Documents/test.caf
Any ideas? 🧐🤔
Many thanks!
EDIT: Before storing the url as a property, I was doing the following, recalculating the documentsDirectory in VC#2 however was also not succesfull:
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
let results = try? FileManager.default.contentsOfDirectory(atPath: documentsDirectory.absoluteString)

Answer 1

You cannot save a sandboxed file URL or path string for later use, because the sandbox can move. You need to do what you were doing before, successfully: calculate the documents directory URL and then examine it. You should work entirely with URLs and never call absoluteString at all; it is the wrong call entirely and is letting you down here.
In this example, I check the documents directory for any files whatever:
let documentsDirectory =
FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
let results =
try? FileManager.default.contentsOfDirectory(at: documentsDirectory,
includingPropertiesForKeys: nil)