Unable to save data in NSUserDefaults with crash with Signal SIGABRT

Question

I am trying to save NSData in NSUserDefaults in a loop, but I'm constantly getting an error.

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *index = [NSString stringWithFormat:@"alltweetsoftrend%d", i];
[defaults setObject:tweetData forKey:index];

[defaults synchronize];

Where i is index of the loop, it means key is not null in any case. I have also checked my NSData(tweetData) and this also is not null. I am just getting this error in saving.

does your `tweetData` confirm to NSCopying protocol. http://stackoverflow.com/questions/1459598/how-to-copy-an-object-in-objective-c — gauravds, May 31 '16 at 14:26
That's not the exception text. iOS will have generated a `NSException` with an explanation of the issue. I assume you are running this inside Xcode? — trojanfoe, May 31 '16 at 14:28
NSUserDefaults is for storing small amounts of data. Have you tried writing this to a file and putting the file name in NSUserDefaults? NSData has a writeToFile method. — Charles A., May 31 '16 at 14:29
your `tweetData` data need to copy on userdefault, so required to implement it. Implement that protocol or convert your `tweetData` into NSData, NSString etc. — gauravds, May 31 '16 at 14:30
@CharlesA. No i didnt tried. I have saved even MBs in Nsuserdefaults but now its just some Bytes that are unable to store — Zaheer Udeen Babar, May 31 '16 at 14:31
Update the question with the code where you are defining/setting the tweetData/ NSData — Xcoder, May 31 '16 at 14:38
@Xcoder I am simply storing NSData using async requests in other activity and i have checked that tweetdata is not empty or corrupt. I am recieving user tweets in that and im sure NSdata is not empty. — Zaheer Udeen Babar, May 31 '16 at 14:46
Ok. Just wanted to make sure that you are not equating the tweetdata to an array or dictionary from the response. — Xcoder, May 31 '16 at 14:53
No, Response comes in NSdata and i can convert into Nsdictionary or NSarray with successful results but unable to store it for further usage. — Zaheer Udeen Babar, May 31 '16 at 14:55

score 2 · Accepted Answer · answered Jun 01 '16 at 04:36

There's nothing inherently wrong with your code. There's a slight chance the NSData is too large to store, but I wouldn't really expect a SIGABRT in that case. The most likely issue is that the NSData was created with [NSData dataWithBytesNoCopy:length:] and the buffer that the NSData pointed to was deallocated. There could be other issues that cause the problem as well, such as using a shared NSData global variable between threads, incorrect typecasting from CFDataRefs, etc, etc.

Try writing a different NSData and see if it works. For example: NSData *tweetData = [NSData dataWithBytes:"Hello" length:6];. I bet that works, so the problem has to do with how your tweetData was created and sent into this code.

Yes! Size of NSData was large. I have done that by storing That into a file in document directory. — Zaheer Udeen Babar, Jun 01 '16 at 08:39

Unable to save data in NSUserDefaults with crash with Signal SIGABRT

1 Answers1