Parsing a Django-created JSON

Question

I recognize that there are a lot of SO topics on this already but all of them seem quite dated.

IE: SBJSON parsing issue with Twitter's GET trends/:woeid and JSONValue ARC issue

However, my JSON response is a little different.

This is the raw string (created from a Django backend):

 [
  {"user":  "[
              {\"id\": \"48\"}, 
              {\"email_address\": null}, 
              {\"password\": \"f41fd61838bc65d6b2c656d488e33aba\"}, 
              {\"salt\": \"24\"}, 
              {\"date_created\": \"2013-01-27 07:59:26.722311+00:00\"},
              {\"date_modified\": \"2013-01-27 07:59:26.722357+00:00\"}, 
              {\"is_deleted\": \"False\"}
            ]"
   }
 ]

The thing stopping me from just using SBJson and it's SBJSonParser and/or the Apple NSJSONSeriliazatoin class + methods are the two quotation marks after "user": and before the second [ (as well as it's enclosing quote cousin, after the second last ]).

Those quotes mess up both of the mentioned solutions in converting NSMutableString into a JSON object.

Any advice/solutions in either removing the offending quotes and/or a JSON parsing library that deals with them effectively?

NSScanner and perhaps some NSMutableString class methods but nothing exceptionally obvious springs to my mind.

Looking for a simple novel solution.

The simplest solution would be to make sure your backend is producing valid JSON, which this isn't. — jrturton, Jan 27 '13 at 08:49
The next simplest solution would be to replace those occurrences of "[ and ]" with [ and ]. See my answer below. — LJ Wilson, Jan 27 '13 at 14:54

Daij-Djan · Answer 1 · 2013-01-27T09:40:23.913

the JSON you show is kinda.. not valid... The above is a nested JSON:

an array with dict with a user key == String of another JSON
an array with n dicts of JSON

it could be parsed in 2 steps I guess...

    id s = @"[ \n \
            {\"user\": \"[%@]\" \n \
            } \n \
     ]";
    id s2 = @"{\\\"id\\\": \\\"48\\\"},{\\\"email_address\\\": \\\"null\\\"},{\\\"password\\\": \\\"f41fd61838bc65d6b2c656d488e33aba\\\"},{\\\"salt\\\": \\\"24\\\"},{\\\"date_created\\\": \\\"2013-01-27 07:59:26.722311+00:00\\\"},{\\\"date_modified\\\": \\\"2013-01-27 07:59:26.722357+00:00\\\"},{\\\"is_deleted\\\": \\\"False\\\"}";
    s = [NSString stringWithFormat:s,s2];
    id d = [s dataUsingEncoding:NSUTF8StringEncoding];
    NSLog(@"\n%@ %@", s, d);
    NSError *error = nil;
    id outerJSON = [NSJSONSerialization JSONObjectWithData:d options:0 error:&error];
    if(!outerJSON && error) {
        NSLog(@"%@", error);
        return -1;
    }
    NSLog(@"\n%@", outerJSON);

    s = [[outerJSON objectAtIndex:0] objectForKey:@"user"];
    d = [s dataUsingEncoding:NSUTF8StringEncoding];
    id innerJSON = [NSJSONSerialization JSONObjectWithData:d options:0 error:&error];
    if(!innerJSON && error) {
        NSLog(@"%@", error);
        return -1;
    }
    NSLog(@"\n%@", innerJSON);

score 1 · Accepted Answer · answered Jan 27 '13 at 13:51

Like the others have said, that is not valid JSON. Fixing it on the backend would be the best solution, but if you cannot - this should work for you:

NSString *dJangoString = @"[{\"user\":  \"[{\"id\": \"48\"},{\"email_address\": null},{\"password\":\"f41fd61838bc65d6b2c656d488e33ab\"},{\"salt\": \"24\"},{\"date_created\": \"2013-01-27 07:59:26.722311+00:00\"},{\"date_modified\": \"2013-01-27 07:59:26.722357+00:00\"},{\"is_deleted\": \"False\"}]\"}]\"";

dJangoString = [dJangoString stringByReplacingOccurrencesOfString:@"\"[" withString:@"["];
dJangoString = [dJangoString stringByReplacingOccurrencesOfString:@"]\"" withString:@"]"];

NSData* dJangoData = [dJangoString dataUsingEncoding:NSUTF8StringEncoding];
NSError *error = nil;
id retObj = [NSJSONSerialization JSONObjectWithData:dJangoData options:0 error:&error];

NSLog(@"retObj = %@", [retObj description]);

Thanks, yeah I discussed it with our backend guy. I was kinda confuzzled as well, never saw something formatted like that before. Anyways, after discussing I now get to work with awesomely well formatted (read properly) JSON! :( to 3 hours wasted though. — samuelsaumanchan, Jan 28 '13 at 04:34

Parsing a Django-created JSON

2 Answers2