Trying to parse JSON data from Flickr. Cocoa error 3840 - objective-c

Question

I’ve never used an API in conjunction with web services before and I’m having trouble parsing the JSON data I’m receiving from Flickr’s API. The only thing I do know (from all the things I have read) is that it is easy and very simple. About as far as I can get is returning a string in the console. Using a dictionary returns null and or an error. What am I missing? I want to be able to pull out the id and owner so that I can get the photo url.
This returns data on my photo:
NSString *json = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#”%#”, json); //this returns data on my photo
This returns null(resultDict) and error 3840:
NSString *requestString = #”https://api.flickr.com/services/rest?&method=......etc;
NSURL *url = [NSURL URLWithString:requestString];
NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:config];
NSURLSessionDataTask *task = [session dataTaskWithURL:url
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
NSMutableDictionary *resultdict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];
NSLog(#”%#”, resultDict); //returns null
If (error != nil) { NSLog(#”%#”, [error localizedDescription]); }
else { self.myDict = [[resultDict objectforKey:#”photos”] objectAtIndex:0];
NSLog(#”%#”, self.myDict); }
}];
[task resume];
To check if I have an array of dictionaries I did the following and it returned 0:
NSMutableArray *resultArray = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainer error:&error]; error:&error];
NSLog(#"%lu", (unsigned long)resultArray.count);

Answer 1

Are you sure that
[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];
returns a Dictionary and not an Array of Dictionnaries?
EDIT :
Can you try to use this to request the API please?
I checked in my projects, my reponses seems to have the same syntax as yours.
Only the code I use is different.
(If you could give us the full URL you've to call, it would be easier for us ^^')
NSString *str=#"YOUR URL";
NSURL *url=[NSURL URLWithString:str];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:5.0];
NSData *returnData = [NSURLConnection sendSynchronousRequest: request returningResponse:&response error: &error];
NSMutableDictionary* resultList = [NSJSONSerialization JSONObjectWithData:returnData options:NSJSONReadingMutableContainers error:nil];
I copied it without the errors. I let you manage that ^^

Answer 2

NSMutableDictionary ***resultdict** = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];
NSLog(#”%#”, **resultDict**); //returns null
resultdict and resultDict are not the same variables. I bet you have an instance variable or a global variable somewhere named resultDict. Instance variables should start with an underscore, among other reasons because it avoids problems like this.

Answer 3

For question maker this answer won't be actual but maybe for them who will face with such problem.
I had the same problem when tried to get data from flickr.photos.getRecent method. I forgot to add into URL parametrs value nojsoncallback=1.
Without it you get response in JSONP.