I did test this code, but it cause SIGABRT error.
NSArray *array = [NSKeyedUnarchiver unarchiveObjectWithData:data]
NSData is plist data with xml format. This code works fine.
[urlData writeToFile:[self docPath] atomically:YES];
array = [[NSMutableArray alloc] initWithContentsOfFile:[self docPath]];
How can I change NSData to NSArray without file conversion?