NSURLErrorDomain error codes description
Solution 1:
The NSURLErrorDomain
error codes are listed here https://developer.apple.com/documentation/foundation/1508628-url_loading_system_error_codes
However, 400 is just the http status code (http://www.w3.org/Protocols/HTTP/HTRESP.html) being returned which means you've got something wrong with your request.
Solution 2:
I was unable to find name of an error for given code when developing in Swift. For that reason I paste minus codes for NSURLErrorDomain
taken from NSURLError.h
/*!
@enum NSURL-related Error Codes
@abstract Constants used by NSError to indicate errors in the NSURL domain
*/
NS_ENUM(NSInteger)
{
NSURLErrorUnknown = -1,
NSURLErrorCancelled = -999,
NSURLErrorBadURL = -1000,
NSURLErrorTimedOut = -1001,
NSURLErrorUnsupportedURL = -1002,
NSURLErrorCannotFindHost = -1003,
NSURLErrorCannotConnectToHost = -1004,
NSURLErrorNetworkConnectionLost = -1005,
NSURLErrorDNSLookupFailed = -1006,
NSURLErrorHTTPTooManyRedirects = -1007,
NSURLErrorResourceUnavailable = -1008,
NSURLErrorNotConnectedToInternet = -1009,
NSURLErrorRedirectToNonExistentLocation = -1010,
NSURLErrorBadServerResponse = -1011,
NSURLErrorUserCancelledAuthentication = -1012,
NSURLErrorUserAuthenticationRequired = -1013,
NSURLErrorZeroByteResource = -1014,
NSURLErrorCannotDecodeRawData = -1015,
NSURLErrorCannotDecodeContentData = -1016,
NSURLErrorCannotParseResponse = -1017,
NSURLErrorAppTransportSecurityRequiresSecureConnection NS_ENUM_AVAILABLE(10_11, 9_0) = -1022,
NSURLErrorFileDoesNotExist = -1100,
NSURLErrorFileIsDirectory = -1101,
NSURLErrorNoPermissionsToReadFile = -1102,
NSURLErrorDataLengthExceedsMaximum NS_ENUM_AVAILABLE(10_5, 2_0) = -1103,
// SSL errors
NSURLErrorSecureConnectionFailed = -1200,
NSURLErrorServerCertificateHasBadDate = -1201,
NSURLErrorServerCertificateUntrusted = -1202,
NSURLErrorServerCertificateHasUnknownRoot = -1203,
NSURLErrorServerCertificateNotYetValid = -1204,
NSURLErrorClientCertificateRejected = -1205,
NSURLErrorClientCertificateRequired = -1206,
NSURLErrorCannotLoadFromNetwork = -2000,
// Download and file I/O errors
NSURLErrorCannotCreateFile = -3000,
NSURLErrorCannotOpenFile = -3001,
NSURLErrorCannotCloseFile = -3002,
NSURLErrorCannotWriteToFile = -3003,
NSURLErrorCannotRemoveFile = -3004,
NSURLErrorCannotMoveFile = -3005,
NSURLErrorDownloadDecodingFailedMidStream = -3006,
NSURLErrorDownloadDecodingFailedToComplete =-3007,
NSURLErrorInternationalRoamingOff NS_ENUM_AVAILABLE(10_7, 3_0) = -1018,
NSURLErrorCallIsActive NS_ENUM_AVAILABLE(10_7, 3_0) = -1019,
NSURLErrorDataNotAllowed NS_ENUM_AVAILABLE(10_7, 3_0) = -1020,
NSURLErrorRequestBodyStreamExhausted NS_ENUM_AVAILABLE(10_7, 3_0) = -1021,
NSURLErrorBackgroundSessionRequiresSharedContainer NS_ENUM_AVAILABLE(10_10, 8_0) = -995,
NSURLErrorBackgroundSessionInUseByAnotherProcess NS_ENUM_AVAILABLE(10_10, 8_0) = -996,
NSURLErrorBackgroundSessionWasDisconnected NS_ENUM_AVAILABLE(10_10, 8_0)= -997,
};