Saving to iCloud with saveToURL:forSaveOperation: completionHandler: fails - ios

Question

I am trying to save a Dictionary of objects to iCloud but when I do it method saveToURL:forSaveOperation: completionHandler: fails. I also tried to override:
- (BOOL)writeContents:(id)contents
andAttributes:(NSDictionary *)additionalFileAttributes
safelyToURL:(NSURL *)url
forSaveOperation:(UIDocumentSaveOperation)saveOperation
error:(NSError **)outError
and of course the super call also returns false. Yet, I would have liked to read the error, but when I try to have the localizedError the compiler reports an error claiming it is not a structure or union.
This is the full piece of code:
-(instancetype)initWithSingleton{
NSURL *ubiq = [[NSFileManager defaultManager]
URLForUbiquityContainerIdentifier:nil];
NSURL *ubiquitousPackage = [[ubiq URLByAppendingPathComponent:
#"Stops"] URLByAppendingPathComponent:kFILENAME];
NSLog(#"file url=%#", ubiquitousPackage);
self=[self initWithFileURL:ubiquitousPackage];
if (self!=nil){
self.favoriteStops=[[NSMutableDictionary alloc] init];
NSURL *ubiq = [[NSFileManager defaultManager]
URLForUbiquityContainerIdentifier:nil];
if (ubiq) {
NSLog(#"iCloud access at %#", ubiq);
[self loadDocument];
} else {
NSLog(#"No iCloud access");
}
}
return self;
}
#define kFILENAME #"favorite.dox"
- (void)loadData:(NSMetadataQuery *)query {
if ([query resultCount] == 1) {
NSMetadataItem *item = [query resultAtIndex:0];
NSURL *url = [item valueForAttribute:NSMetadataItemURLKey];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSURLResponse *response;
NSData *GETReply= [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];
NSMutableDictionary* dict=[NSKeyedUnarchiver unarchiveObjectWithData:GETReply];
[self setFavoriteStops:dict];
NSLog(#"favorites: %#", favoriteStops);
[self openWithCompletionHandler:^(BOOL success) {
if (success) {
NSLog(#"iCloud document opened");
} else {
NSLog(#"failed opening document from iCloud");
}
}];
}
}
- (void)queryDidFinishGathering:(NSNotification *)notification {
NSMetadataQuery *query = [notification object];
[query disableUpdates];
[query stopQuery];
[[NSNotificationCenter defaultCenter] removeObserver:self
name:NSMetadataQueryDidFinishGatheringNotification
object:query];
_query = nil;
[self loadData:query];
}
- (BOOL)loadFromContents:(id)contents ofType:(NSString *)typeName
error:(NSError **)outError
{
if ([contents length] > 0) {
[self setFavoriteStops:[NSKeyedUnarchiver unarchiveObjectWithData:contents]];
}
return YES;
}
- (BOOL)writeContents:(id)contents
andAttributes:(NSDictionary *)additionalFileAttributes
safelyToURL:(NSURL *)url
forSaveOperation:(UIDocumentSaveOperation)saveOperation
error:(NSError **)outError{
//logging
NSString *str;
str= [[NSString alloc] initWithData:contents encoding:NSUTF8StringEncoding];
NSLog(#"saving data %#", str);
//logging
NSMutableDictionary *dict=[NSKeyedUnarchiver unarchiveObjectWithData:contents];
NSLog(#"dict=%#", dict);
BOOL success= [super writeContents:contents
andAttributes:additionalFileAttributes
safelyToURL:url
forSaveOperation:saveOperation
error:outError];
NSLog(#"error :%#", outError.localizedDescription) //syntax error
return success;
}
-(void) save{
NSLog(#"file url=%#", [self fileURL]);
[self saveToURL:[self fileURL]
forSaveOperation:UIDocumentSaveForOverwriting
completionHandler:^(BOOL success) {
if (success) { //this returns false
[self openWithCompletionHandler:^(BOOL success) {
NSLog(#"new document saved on iCloud");
}];
} else {
NSLog(#"error in iCloud Saving");
}
}];
}
- (id)contentsForType:(NSString *)typeName error:(NSError **)outError
{
NSLog(#"favorite stops=%# class=%#", self.favoriteStops, [favoriteStops class]);
NSData *archivedData=[NSKeyedArchiver archivedDataWithRootObject:self.favoriteStops];
return archivedData;
}
When I log the url on which to save, that is:
file:///private/var/mobile/Library/Mobile%20Documents/iCloud~com~information~inArrivo/Stops/favorite.dox
And when I check the error on the debugger it is:
Error Domain=NSCocoaErrorDomain Code=4 "The operation couldn’t be
completed. (Cocoa error 4.)" UserInfo=0x17bd6cb0
{NSFileNewItemLocationKey=file:///private/var/mobile/Applications/445778BF-86AF-4DE3-9E1B-BAC8F79D14D0/tmp/(A%20Document%20Being%20Saved%20By%20In%20Arrivo%20HD)/favorite.dox,
NSFileOriginalItemLocationKey=file:///private/var/mobile/Library/Mobile%20Documents/iCloud~com~information~inArrivo/Stops/favorite.dox,
NSUnderlyingError=0x17bfa860 "The operation couldn’t be completed.
(Cocoa error 4.)",
NSURL=file:///private/var/mobile/Library/Mobile%20Documents/iCloud~com~information~inArrivo/Stops/favorite.dox}
How may I fix it or at least know more?

Answer 1

The TSI Apple team answered me and provided me with a working class. Upon checking their version with mine the change seems to boil down to an update to - (void)queryDidFinishGathering:(NSNotification *)notification; by adding:
if (query.results == 0)
{
[self save]; // no favorites file, so create one
}
to make it as follows:
- (void)queryDidFinishGathering:(NSNotification *)notification {
NSMetadataQuery *query = [notification object];
[query disableUpdates];
[query stopQuery];
[[NSNotificationCenter defaultCenter] removeObserver:self
name:NSMetadataQueryDidFinishGatheringNotification
object:query];
//•• added
if (query.results == 0)
{
[self save]; // no favorites file, so create one
}
[self loadData:query];
_query = nil;
}