We are writing an iOS app that uploads data to Google Firebase storage. We use the code below to upload text data to the location we specify. It works fine, except when we are not connected to the internet.

For the case of not being connected to the internet, we are having trouble trapping and handling the error. As far as we can tell, the delegate is never called (MyFirebaseProtocol_UploadTextComplete doesn't fire until much later, perhaps after a timeout) , and it just tries to upload repeatedly. If we are connected to the Mac and watching the debug window, it continuously generates errors in a loop, indefinitely. These certainly look like they are intended to be trappable (class names like NSErrorFailingURLStringKey, and helpful error messages and codes), but so far we are unable to trap them as they occur.

We are relatively new at swift, but is there some syntax, something like exception handling, that will allow us to trap and handle these errors, rather than just loop indefinitely?

Thanks!

func UploadTextFile(filepath : String, text: String, delegate : MyFirebaseProtocol)
{
    let storage = Storage.storage()
    let storageRef = storage.reference()
    let textfileref = storageRef.child(filepath)
    let data: Data? = text.data(using: .utf8)
    
    textfileref.putData(data!, metadata: nil)
    {
        (metadata, error) in
        delegate.MyFirebaseProtocol_UploadTextComplete(error: error)
    }
}

Error messages in Xcode debug window:

2022-01-20 15:15:38.553528-0500 GarmentTest[431:60410] Connection 1: received failure notification

2022-01-20 15:15:38.553552-0500 GarmentTest[431:60410] Connection 1: failed to connect 1:50, reason -1

2022-01-20 15:15:38.553564-0500 GarmentTest[431:60410] Connection 1: encountered error(1:50)

2022-01-20 15:15:38.555426-0500 GarmentTest[431:60410] Connection 2: received failure notification

2022-01-20 15:15:38.555442-0500 GarmentTest[431:60410] Connection 2: failed to connect 1:50, reason -1

2022-01-20 15:15:38.555452-0500 GarmentTest[431:60410] Connection 2: encountered error(1:50)

2022-01-20 15:15:38.557057-0500 GarmentTest[431:60410] Task .<1> HTTP load failed, 0/0 bytes (error code: -1009 [1:50])

2022-01-20 15:15:38.557104-0500 GarmentTest[431:60410] Task <1D0E3033-5A15-4435-AF3D-99A06EAB4C3C>.<2> HTTP load failed, 0/0 bytes (error code: -1009 [1:50])

2022-01-20 15:15:38.557485-0500 GarmentTest[431:60410] Connection 3: received failure notification

2022-01-20 15:15:38.557544-0500 GarmentTest[431:60410] Connection 3: failed to connect 1:50, reason -1

2022-01-20 15:15:38.557664-0500 GarmentTest[431:60410] Connection 3: encountered error(1:50)

2022-01-20 15:15:38.558844-0500 GarmentTest[431:60268] Task .<1> finished with error [-1009] Error Domain=NSURLErrorDomain Code=-1009 "The Internet connection appears to be offline." UserInfo={_kCFStreamErrorCodeKey=50, NSUnderlyingError=0x280374a80 {Error Domain=kCFErrorDomainCFNetwork Code=-1009 "(null)" UserInfo={_kCFStreamErrorCodeKey=50, _kCFStreamErrorDomainKey=1}}, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask .<1>, _NSURLErrorRelatedURLSessionTaskErrorKey=( "LocalDataTask .<1>" ), NSLocalizedDescription=The Internet connection appears to be offline., NSErrorFailingURLStringKey=https://firebasestorage.googleapis.com/v0/b/garmenttest-8897e.appspot.com/o/Snapshots%2FAn%2FAn_20220120_151528_Relaxed_Center_Image_1B.png?uploadType=resumable&name=Snapshots%2FAn%2FAn_20220120_151528_Relaxed_Center_Image_1B.png, NSErrorFailingURLKey=https://firebasestorage.googleapis.com/v0/b/garmenttest-8897e.appspot.com/o/Snapshots%2FAn%2FAn_20220120_151528_Relaxed_Center_Image_1B.png?uploadType=resumable&name=Snapshots%2FAn%2FAn_20220120_151528_Relaxed_Center_Image_1B.png, _kCFStreamErrorDomainKey=1}