On my first attempt at adding iCloud to my existing app this is how far I've gotten. For reasons that I won't go into, the use case for my app does not need coordination. I have successfully made my app write a file to the Documents directory of iCloud and read back that same file without errors. In testing on a real iPhone 13 and iPhone 7 I have verified that my app can write a file to iCloud from the iPhone 7 and then read back that same file on the iPhone 13, so I know that the file truly exists in the cloud. But when I make my app on the iPhone 13 write to iCloud, my app on the iPhone 7 says the file does not exist. Exactly the same build of my app is running in both phones. This is problem #1. Problem #2 is that none of these files appear in the iCloud section of the Files app on either of these Phones, nor do they appear in the iCloud section of my Mac. All devices are signed in to my same Apple account in iCloud. Also my info.plist file in the app contains:
<key>NSUbiquitousContainers</key>
<dict>
<dict>
<key>iCloud.com.{my domain}.{my app}</key>
<dict>
<key>NSUbiquitousContainerIsDocumentScopePublic</key>
<true/>
<key>NSUbiquitousContainerSupportedFolderLevels</key>
<string>Any</string>
<key>NSUbiquitousContainerName</key>
<string>{my app}</string>
</dict>
</dict>
</dict>
<key>UIFileSharingEnabled</key><true/>
The iPhone 7 is running iOS 15.8.4 and the iPhone 13 is running iOS 18.3.2.
The code that does the writing to iCloud is:
NSFileManager *fman = [NSFileManager defaultManager];
NSURL *urlDrive = [fman URLForUbiquityContainerIdentifier: nil];
NSURL *urlDocs = [urlDrive URLByAppendingPathComponent:@"Documents"];
if(urlDocs.path == nil) {
NSLog(@"NULL path");
return; //..big problem
}
if( ! [fman fileExistsAtPath: urlDocs.path] ) { //..need to create the Docs directory
NSError *err00 = nil;
@try {
[fman createDirectoryAtURL: urlDocs withIntermediateDirectories:true
attributes:nil error:&err00];
NSLog(@"created the directory");
} @catch (NSException *except) {
NSLog(@"Exception creating directory %@", except);
}
} //..directory is now created
NSLog(@"url=%@", urlDocs);
NSURL *urlFile = [urlDocs URLByAppendingPathComponent:txtfname()];
NSData *fdata = [@"Hello world" dataUsingEncoding: NSUTF8StringEncoding];
NSLog(@"file url=%@", urlFile);
NSLog(@"file Data=%@", fdata);
NSError *errorReturn = nil;
Boolean ret = [fdata writeToURL: urlFile options: NSDataWritingAtomic error: &errorReturn];
NSLog(@"returned %1d, error=%@", ret?1:0, errorReturn);
And the code that does the reading is:
NSFileManager *fman = [NSFileManager defaultManager];
NSURL *urlDrive = [fman URLForUbiquityContainerIdentifier: nil];
NSURL *urlDocs = [urlDrive URLByAppendingPathComponent:@"Documents"];
NSLog(@"url=%@", urlDocs);
if(urlDocs.path == nil) {
NSLog(@"urlDocs.path is NULL!");
return; //..big problem
}
if( ! [fman fileExistsAtPath: urlDocs.path] ) { //..need to create the Docs directory
NSLog(@"It seems the urlDocs folder does not exist");
}
NSURL *urlFile = [urlDocs URLByAppendingPathComponent:txtfname()];
if([fman fileExistsAtPath: urlFile.path]) {
NSLog(@"file %@ exists", urlFile);
[fman copyItemAtURL: urlFile toURL:<#(nonnull NSURL *)#> error:<#(NSError *__autoreleasing _Nullable * _Nullable)#>];
} else {
NSLog(@"file %@ DOES NOT EXIST!", urlFile);
}