How can i save NSData in iCloud

Question

I have NSData in my App and i want to save that data in iCloud. I DONT want to synchronize my NSUserDefaults with iCloud, so its no clone of "Can I use iCloud to sync the NSUserDefaults plist file". Is that possible? How can i do that? How can I retrieve that saved data?

Answer 1

Yes it is possible. I have done that before and my answer is at syncing zip with iCloud,in which I am creating zip and converting it into NSData and syncing with iCloud, later I am receiving NSData and again converting back it into zip and unzipping content. Here your main need is syncing of NSData so All you to have work around for NSData.

1) Create subclass of UIDocument

#import <UIKit/UIKit.h>

@interface MyDocument : UIDocument
    @property (strong) NSData *dataContent;
@end

2) MyDocument.m

#import "MyDocument.h"

@implementation MyDocument
@synthesize dataContent;

// Called whenever the application reads data from the file system
- (BOOL)loadFromContents:(id)contents ofType:(NSString *)typeName error:(NSError **)outError
{
    self.dataContent = [[NSData alloc] initWithBytes:[contents bytes] length:[contents length]];
    [[NSNotificationCenter defaultCenter] postNotificationName:@"noteModified" object:self];
    return YES;     
}

// Called whenever the application (auto)saves the content of a note
- (id)contentsForType:(NSString *)typeName error:(NSError **)outError 
{
    return self.dataContent;
}

@end

3) Syncing with iCloud (You can do as per you need)

-(IBAction) iCloudSyncing:(id)sender
{

    NSURL* ubiq = [[NSFileManager defaultManager]URLForUbiquityContainerIdentifier:nil];
    NSURL *ubiquitousPackage = [[ubiq URLByAppendingPathComponent:@"Documents"]  URLByAppendingPathComponent:@"iCloudPictures.zip"];

    MyDocument *mydoc = [[MyDocument alloc] initWithFileURL:ubiquitousPackage];
    NSData *data = << YOUR NSDATA >>;
    mydoc.dataContent = data;

    [mydoc saveToURL:[mydoc fileURL] forSaveOperation:UIDocumentSaveForCreating completionHandler:^(BOOL success)
     {
         if (success)
         {
             NSLog(@"Synced with icloud");
         }
         else
             NSLog(@"Syncing FAILED with icloud");

     }];
}

Hope this helps..