ios - parsing NSJSONReadingAllowFragments

Question

I am receiving some json data in my app:

NSMutableDictionary *json = [NSJSONSerialization JSONObjectWithData:jsonResponse options:NSJSONReadingAllowFragments error:nil];
        NSLog(@"json :%@", json);

which logs:

json :{
  "email" : "/apex/emailAttachment?documentId=00PZ0000000zAgSMAU&recipientId=003Z000000XzHmJIAV&relatedObjectId=a09Z00000036kc8IAA&subject=Pricing+Comparison"
}

This is exactly what I want.

However, when I go to read the value of the email by doing

[json objectForKey:@"email"]

I receive an invalid argument exception:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* -[NSDictionary initWithDictionary:copyItems:]: dictionary argument is not an NSDictionary'

How can I read this value?

Answer 1

It seems that your server sends "nested JSON": jsonResponse is a JSON string (not a dictionary). The value of that string is again JSON data representing a dictionary.

In that case you have to de-serialize the JSON twice:

NSString *jsonString = [NSJSONSerialization JSONObjectWithData:jsonResponse options:NSJSONReadingAllowFragments error:nil];
NSData *innerJson = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *jsonDict = [NSJSONSerialization JSONObjectWithData:innerJson options:0 error:nil];

NSString *email = jsonDict[@"email"];