NSJSONSerialization crashing app

Question

I have a dictionary that when I log it shows...

{
    Date = "2013-04-30 17:17:18 +0000";
    Description = Kb;
    EventID = "92193e58-c04a-4233-9a6c-1332bc056b20";
    Title = Keyboard;
}

I'm trying to turn it into NSData for a JSON web service like this...

- (NSData *)JSONRepresentation
{
    NSDictionary *dictionary = [self dictionaryObject];

    NSError *jsonError;

    NSData *JSONData = [NSJSONSerialization dataWithJSONObject:dictionary
                                                       options:0
                                                         error:&jsonError];  //This is where the error occurs.

    return JSONData;
}

But every time I run it the app just crashes.

The dictionary is formed properly, the app just crashes at this line.

In AppCode I get the crash report...

EXC_BREAKPOINT (code=EXC_ARM_BREAKPOINT, subcode=0xdefe))

In Xcode the app just stops and if I try to continue it stops with an error...

EXC_BAD_ACCESS (code=1, address=0x0)

Can you provide a bit more context, e.g. the surrounding lines? Where is `jsonError` declared? — Jim, Apr 30 '13 at 17:26
On the line `NSData *JSONData = [NSJSON....`. It stops at that line. In the debugger after the crash I printed out the dictionary so the dictionary is definitely correct. — Fogmeister, Apr 30 '13 at 17:26
@HotLicks That's what I have done. It is printed in the question. — Fogmeister, Apr 30 '13 at 17:29
Are your keys NSString instances? If not this will probably not work. — sosborn, Apr 30 '13 at 17:29
@sosborn They are NSString and NSDate instances. Does the NSDate break it? Shouldn't that just display the error in the jsonError? Will try changing it to NSString now. — Fogmeister, Apr 30 '13 at 17:30
NSDate will break it. Other values should be OK. Here is the list from the docs: `All objects are instances of NSString, NSNumber, NSArray, NSDictionary, or NSNull.` — sosborn, Apr 30 '13 at 17:32
D'oh! Thanks, I have changed it now... and it works! Thanks very much! Not sure why it doesn't just populate the NSError that is passed in though?! Stick it as an answer and I'll accept it :) — Fogmeister, Apr 30 '13 at 17:34
Thanks. By the way I know this because I got burned by it last night :) — sosborn, Apr 30 '13 at 17:37

score 15 · Accepted Answer · answered Apr 30 '13 at 17:36

15

Your keys are invalid objects for converting to JSON. From the docs:

An object that may be converted to JSON must have the following properties:

The top level object is an NSArray or NSDictionary. All objects are instances of NSString, NSNumber, NSArray, NSDictionary, or NSNull. All dictionary keys are instances of NSString. Numbers are not NaN or infinity.

answered Apr 30 '13 at 17:36

sosborn

14,676
2
42
46

1

Thanks very much. The NSDate object was causing the crash. – Fogmeister Apr 30 '13 at 17:36
Great. I had a swift enum that I forgot to pass as a string rawValue which caused this crash for me. – Undrea May 12 '17 at 18:01

score 1 · Answer 2 · answered Jun 30 '21 at 04:35

1

check before, if the dictionary is invalid to convert, return.:

if (![NSJSONSerialization isValidJSONObject:dictionary]) { return; }

answered Jun 30 '21 at 04:35

xcodedeveloper

266
2
8

NSJSONSerialization crashing app

2 Answers2