Swift:URLSessionDownload file says it exists but it doesn't?












11














Ok, I have succeeded in downloading various m4a files as well as removing them via URLSession. My problem is in the final "completion" function of the URLSessionDownloadDelegate requirement, I sometimes get the following printed to console even though I check in my download func( before downloading) whether the file exists in the directory or not. Very confused. Here is message:



File download succesfully
“CFNetworkDownload_1wGgxs.tmp” couldn’t be moved to “Documents” because an item with the same name already exists.
The task finished successfully


Here is download func where I CHECK EXPLICITLY whether file exists:



func goDownload()
{
if let audioUrl = downloadUrl { //set at beginning

let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
print(destinationUrl)

// to check if it exists before downloading it
if FileManager.default.fileExists(atPath: destinationUrl.path) {
print("********** The file already exists at path")

// if the file doesn't exist
} else {

print("---------------> Starting Download")


currentTask = session.downloadTask(with: audioUrl)
currentTask.resume()
}
}
}


Here is completion func:



func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {

print("File download succesfully")
let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

// lets create your destination file url
let destinationUrl = documentsDirectoryURL.appendingPathComponent((downloadUrl?.lastPathComponent)!)

do {
try FileManager.default.moveItem(at: location, to: destinationUrl)

//success
print("************** SUCCESS File moved to documents folder", downloadUrl)
playModeStreaming = false

self.pausePlay()
AudioPlayerManager.shared.play(url: downloadUrl)

} catch let error as NSError {
print(error.localizedDescription)
}


}


I have even implemented a checking func that returns whether the file exists or not and after getting the above message, it returns false:



func checkIfExists(url: URL)->Bool
{
return FileManager.default.fileExists(atPath: url.path)
}


What is causing this? How can I make sure it downloads so that it can play the m4a?










share|improve this question






















  • Hey! Did you find any solution for this ? I am having same error.
    – Viral Narshana
    Jul 28 '17 at 15:02










  • any solutions to this?
    – swalkner
    Jul 25 at 12:45










  • I am having a hard time reproducing this, is it possible to attach a working example on github?
    – J. Doe
    Nov 27 at 11:07
















11














Ok, I have succeeded in downloading various m4a files as well as removing them via URLSession. My problem is in the final "completion" function of the URLSessionDownloadDelegate requirement, I sometimes get the following printed to console even though I check in my download func( before downloading) whether the file exists in the directory or not. Very confused. Here is message:



File download succesfully
“CFNetworkDownload_1wGgxs.tmp” couldn’t be moved to “Documents” because an item with the same name already exists.
The task finished successfully


Here is download func where I CHECK EXPLICITLY whether file exists:



func goDownload()
{
if let audioUrl = downloadUrl { //set at beginning

let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
print(destinationUrl)

// to check if it exists before downloading it
if FileManager.default.fileExists(atPath: destinationUrl.path) {
print("********** The file already exists at path")

// if the file doesn't exist
} else {

print("---------------> Starting Download")


currentTask = session.downloadTask(with: audioUrl)
currentTask.resume()
}
}
}


Here is completion func:



func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {

print("File download succesfully")
let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

// lets create your destination file url
let destinationUrl = documentsDirectoryURL.appendingPathComponent((downloadUrl?.lastPathComponent)!)

do {
try FileManager.default.moveItem(at: location, to: destinationUrl)

//success
print("************** SUCCESS File moved to documents folder", downloadUrl)
playModeStreaming = false

self.pausePlay()
AudioPlayerManager.shared.play(url: downloadUrl)

} catch let error as NSError {
print(error.localizedDescription)
}


}


I have even implemented a checking func that returns whether the file exists or not and after getting the above message, it returns false:



func checkIfExists(url: URL)->Bool
{
return FileManager.default.fileExists(atPath: url.path)
}


What is causing this? How can I make sure it downloads so that it can play the m4a?










share|improve this question






















  • Hey! Did you find any solution for this ? I am having same error.
    – Viral Narshana
    Jul 28 '17 at 15:02










  • any solutions to this?
    – swalkner
    Jul 25 at 12:45










  • I am having a hard time reproducing this, is it possible to attach a working example on github?
    – J. Doe
    Nov 27 at 11:07














11












11








11


1





Ok, I have succeeded in downloading various m4a files as well as removing them via URLSession. My problem is in the final "completion" function of the URLSessionDownloadDelegate requirement, I sometimes get the following printed to console even though I check in my download func( before downloading) whether the file exists in the directory or not. Very confused. Here is message:



File download succesfully
“CFNetworkDownload_1wGgxs.tmp” couldn’t be moved to “Documents” because an item with the same name already exists.
The task finished successfully


Here is download func where I CHECK EXPLICITLY whether file exists:



func goDownload()
{
if let audioUrl = downloadUrl { //set at beginning

let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
print(destinationUrl)

// to check if it exists before downloading it
if FileManager.default.fileExists(atPath: destinationUrl.path) {
print("********** The file already exists at path")

// if the file doesn't exist
} else {

print("---------------> Starting Download")


currentTask = session.downloadTask(with: audioUrl)
currentTask.resume()
}
}
}


Here is completion func:



func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {

print("File download succesfully")
let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

// lets create your destination file url
let destinationUrl = documentsDirectoryURL.appendingPathComponent((downloadUrl?.lastPathComponent)!)

do {
try FileManager.default.moveItem(at: location, to: destinationUrl)

//success
print("************** SUCCESS File moved to documents folder", downloadUrl)
playModeStreaming = false

self.pausePlay()
AudioPlayerManager.shared.play(url: downloadUrl)

} catch let error as NSError {
print(error.localizedDescription)
}


}


I have even implemented a checking func that returns whether the file exists or not and after getting the above message, it returns false:



func checkIfExists(url: URL)->Bool
{
return FileManager.default.fileExists(atPath: url.path)
}


What is causing this? How can I make sure it downloads so that it can play the m4a?










share|improve this question













Ok, I have succeeded in downloading various m4a files as well as removing them via URLSession. My problem is in the final "completion" function of the URLSessionDownloadDelegate requirement, I sometimes get the following printed to console even though I check in my download func( before downloading) whether the file exists in the directory or not. Very confused. Here is message:



File download succesfully
“CFNetworkDownload_1wGgxs.tmp” couldn’t be moved to “Documents” because an item with the same name already exists.
The task finished successfully


Here is download func where I CHECK EXPLICITLY whether file exists:



func goDownload()
{
if let audioUrl = downloadUrl { //set at beginning

let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
print(destinationUrl)

// to check if it exists before downloading it
if FileManager.default.fileExists(atPath: destinationUrl.path) {
print("********** The file already exists at path")

// if the file doesn't exist
} else {

print("---------------> Starting Download")


currentTask = session.downloadTask(with: audioUrl)
currentTask.resume()
}
}
}


Here is completion func:



func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {

print("File download succesfully")
let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

// lets create your destination file url
let destinationUrl = documentsDirectoryURL.appendingPathComponent((downloadUrl?.lastPathComponent)!)

do {
try FileManager.default.moveItem(at: location, to: destinationUrl)

//success
print("************** SUCCESS File moved to documents folder", downloadUrl)
playModeStreaming = false

self.pausePlay()
AudioPlayerManager.shared.play(url: downloadUrl)

} catch let error as NSError {
print(error.localizedDescription)
}


}


I have even implemented a checking func that returns whether the file exists or not and after getting the above message, it returns false:



func checkIfExists(url: URL)->Bool
{
return FileManager.default.fileExists(atPath: url.path)
}


What is causing this? How can I make sure it downloads so that it can play the m4a?







ios swift nsurlsession nsurlsessiondownloadtask






share|improve this question













share|improve this question











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share|improve this question










asked Jul 1 '17 at 19:06









skyguy

2,50172971




2,50172971












  • Hey! Did you find any solution for this ? I am having same error.
    – Viral Narshana
    Jul 28 '17 at 15:02










  • any solutions to this?
    – swalkner
    Jul 25 at 12:45










  • I am having a hard time reproducing this, is it possible to attach a working example on github?
    – J. Doe
    Nov 27 at 11:07


















  • Hey! Did you find any solution for this ? I am having same error.
    – Viral Narshana
    Jul 28 '17 at 15:02










  • any solutions to this?
    – swalkner
    Jul 25 at 12:45










  • I am having a hard time reproducing this, is it possible to attach a working example on github?
    – J. Doe
    Nov 27 at 11:07
















Hey! Did you find any solution for this ? I am having same error.
– Viral Narshana
Jul 28 '17 at 15:02




Hey! Did you find any solution for this ? I am having same error.
– Viral Narshana
Jul 28 '17 at 15:02












any solutions to this?
– swalkner
Jul 25 at 12:45




any solutions to this?
– swalkner
Jul 25 at 12:45












I am having a hard time reproducing this, is it possible to attach a working example on github?
– J. Doe
Nov 27 at 11:07




I am having a hard time reproducing this, is it possible to attach a working example on github?
– J. Doe
Nov 27 at 11:07












1 Answer
1






active

oldest

votes


















3





+25









Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



The checking code from Apple's site:



...
didFinishDownloadingTo location: URL) {

guard let httpResponse = downloadTask.response as? HTTPURLResponse,
(200...299).contains(httpResponse.statusCode) else {
print ("server error")
return
}

... now do the FileManager code





share|improve this answer





















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    1 Answer
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    active

    oldest

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    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    3





    +25









    Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



    The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



    You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



    The checking code from Apple's site:



    ...
    didFinishDownloadingTo location: URL) {

    guard let httpResponse = downloadTask.response as? HTTPURLResponse,
    (200...299).contains(httpResponse.statusCode) else {
    print ("server error")
    return
    }

    ... now do the FileManager code





    share|improve this answer


























      3





      +25









      Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



      The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



      You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



      The checking code from Apple's site:



      ...
      didFinishDownloadingTo location: URL) {

      guard let httpResponse = downloadTask.response as? HTTPURLResponse,
      (200...299).contains(httpResponse.statusCode) else {
      print ("server error")
      return
      }

      ... now do the FileManager code





      share|improve this answer
























        3





        +25







        3





        +25



        3




        +25




        Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



        The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



        You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



        The checking code from Apple's site:



        ...
        didFinishDownloadingTo location: URL) {

        guard let httpResponse = downloadTask.response as? HTTPURLResponse,
        (200...299).contains(httpResponse.statusCode) else {
        print ("server error")
        return
        }

        ... now do the FileManager code





        share|improve this answer












        Your code is very close to Apple's sample code in the section titled "Handle Download Completion and Errors". But not quite... your print("File download succesfully") is making a big assumption!



        The delta I see in urlSession:... didFinishDownloadingTo: is that you're skipping the check of downloadTask.response.statusCode to ensure the download was successful. Apple checks it's in the range 200...299.



        You might try adding this HTTP status code check, in case the error message you're getting is bogus and you're actually experiencing network failures.



        The checking code from Apple's site:



        ...
        didFinishDownloadingTo location: URL) {

        guard let httpResponse = downloadTask.response as? HTTPURLResponse,
        (200...299).contains(httpResponse.statusCode) else {
        print ("server error")
        return
        }

        ... now do the FileManager code






        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 22 at 14:44









        Graham Perks

        16.9k64471




        16.9k64471






























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