Question

I’m working with parsing JSON into my app and am running into some issues pulling in just one section of it. For some reason, it seems to be going through my whole JSON feed, logging NULL values except for the one I specify.

Any advice? Thanks for the help!

My Method:

-(void)loadStats {
NSDictionary *totalsfeed = [self downloadTotals]; 
NSArray *totals = (NSArray *)[totalsfeed valueForKey:@"totals"];  
NSLog(@"NEW TOTALS: %@", [totals valueForKey:@"d_monthly_total"]); 
}

Console Results:

2011-08-30 11:35:38.096 App Name [9142:16507] NEW TOTALS: (
"<null>",
"<null>",
2,
"<null>",
"<null>",
"<null>"
)

JSON Feed

{
    "totals": [
        {
            "ab_grand_total": "2217"
        },
        {
            "d_grand_total": "1096"
        },
        {
            "d_monthly_total": "2"
        },
        {
            "ab_monthly_total": "13"
        },
        {
            "ab_yearly_total": "746"
        },
        {
            "d_yearly_total": "233"
        }
    ]
}

I’m parsing the JSON here:

// JSON from Server Actions
- (NSString *)stringWithUrl:(NSURL *)url {
    NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url
                                                cachePolicy:NSURLRequestReloadRevalidatingCacheData
                                            timeoutInterval:30];
    // Fetch the JSON response
    NSData *urlData;
    NSURLResponse *response;
    NSError *error;

    // Make synchronous request
    urlData = [NSURLConnection sendSynchronousRequest:urlRequest
                                    returningResponse:&response
                                                error:&error];

    // Construct a String around the Data from the response
    return [[NSString alloc] initWithData:urlData encoding:NSUTF8StringEncoding];
    }



- (id)objectWithUrl:(NSURL *)url {
    SBJsonParser *jsonParser = [SBJsonParser new];
    NSString *jsonString = [self stringWithUrl:url];

    // Parse the JSON into an Object
    return [jsonParser objectWithString:jsonString error:NULL];
    }
- (NSDictionary *)downloadTotals {
    id totals = [self objectWithUrl:[NSURL URLWithString:@"http://example.com/totals.json"]];
    NSDictionary *totalsfeed = (NSDictionary *)totals;
    return totalsfeed;
    }

Answer 1

totals is an NSArray of NSDictionary objects, so [totals valueForKey:@"d_monthly_total"] does not make sense. Instead, to get d_monthly_total, you should do:

NSDictionary *dMonthlyTotalDictionary = (NSDictionary *)[totals objectAtIndex:2];
NSLog(@"NEW TOTALS: %@", [dMonthlyTotalDictionary objectForKey:"d_monthly_total"]);

To iterate through totals, do:

for(NSDictionary *myDict in totals) {
    for(NSString *key in myDict) {
        NSLog(@"%@: %@", key, [myDict objectForKey:key]);
    }
}