NSData NSDataWritingAtomic example in Objective C (iOS).

NSData NSDataWritingAtomic

NSDataWritingOptions
Options for methods used to write NSData objects.

enum {
NSDataWritingAtomic = 1UL << 0,
NSDataWritingWithoutOverwriting = 1UL << 1,
NSDataWritingFileProtectionNone = 0x10000000,
NSDataWritingFileProtectionComplete = 0x20000000,
NSDataWritingFileProtectionCompleteUnlessOpen = 0x30000000,
NSDataWritingFileProtectionCompleteUntilFirstUserAuthentication = 0x40000000,
NSDataWritingFileProtectionMask = 0xf0000000,
};
typedef NSUInteger NSDataWritingOptions;
Constants
NSDataWritingAtomic
A hint to write data to an auxiliary file first and then exchange the files. This option is equivalent to using a write method taking the parameter atomically:YES.
NSDataWritingWithoutOverwriting
Hint to return prevent overwriting an existing file. Cannot be combined with NSDataWritingAtomic.
NSDataWritingFileProtectionNone
A hint to set the content protection attribute of the file when writing it out. In this case, the file is not stored in an encrypted format and may be accessed at boot time and while the device is unlocked.
Available in iOS 4.0 and later.
Declared in NSData.h.
NSDataWritingFileProtectionComplete
A hint to set the content protection attribute of the file when writing it out. In this case, the file is stored in an encrypted format and may be read from or written to only while the device is unlocked. At all other times, attempts to read and write the file result in failure.
NSDataWritingFileProtectionCompleteUnlessOpen
A hint to set the content protection attribute of the file when writing it out. In this case, the file cannot be opened for reading or writing when the device is locked, although new files can be created with this class. If one of these files is open when the device is locked, reading and writing are still allowed.
NSDataWritingFileProtectionCompleteUntilFirstUserAuthentication
A hint to set the content protection attribute of the file when writing it out. In this case, the file can be read or written to while the device is locked, but while it is booting up, they have protection equivalent to NSDataWritingFileProtectionComplete.
NSDataWritingFileProtectionMask
A mask to use when determining the file protection options assigned to the data.

NSData NSDataWritingAtomic example.

if (data) {   
     NSString *content = [[NSString alloc]  initWithBytes:[data bytes]
                                                      length:[data length] encoding: NSUTF8StringEncoding];

    NSLog(@"%@", content); // verifies data was downloaded correctly

    NSError* error;
    [data writeToFile:storePath options:NSDataWritingAtomic error:&error];

    if(error != nil)
        NSLog(@"write error %@", error);
}

Example of [NSData NSDataWritingAtomic].

NSError *error = nil;
path=@"/Users/aryaxt/Desktop/test2.avi";
[data writeToFile:path options:NSDataWritingAtomic error:&error];
NSLog(@"Write returned error: %@", [error localizedDescription]);

NSData NSDataWritingAtomic example.

-(void)banner:(NSString *)path{
   NSData * imageData = [[NSData alloc] initWithContentsOfURL: [NSURL URLWithString: path]];
   NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);         NSString *filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"banner.png"];      
   NSError *writeError = nil;
   [imageData writeToFile:filePath options:NSDataWritingAtomic error:&writeError];

   if (writeError) {
      NSLog(@"Error writing file: %@", writeError);
   }
}

End of NSData NSDataWritingAtomic example article.