How can we retrieve data in iOS by JSON parsing? - ios

Question

I am calling this method in my Application.
[flickrRequest callAPIMethodWithPOST:#"flickr.photosets.create" arguments:[NSDictionary dictionaryWithObjectsAndKeys:FLICKR_AUTH_TOKEN,#"api_key",albumNAME,#"title",#"13978764555",#"primary_photo_id",#"Uploaded from my iPhone/iPod Touch", #"description", nil]];
JSON Response:
{ "photoset": { "id": "72157644227295321", "url": "https:\/\/www.flickr.com\/photos\/122586274#N04\/sets\/72157644227295321\/" }, "stat": "ok" }
I am getting this response on my log cat, now the problem is that i want to retrieve this "id" in my application,but i am unable to do this. Please help me in the way in which i can retrieve this id?

Answer 1

After the data returned from server, you can convert it to NSDictionary
NSError *error;
NSDictionary *response = [NSJSONSerialization JSONObjectWithData:dataFromServer options:NSJSONReadingMutableContainers error:&error];`
Now since id is in the 2nd layer, so you can do
NSString *id = [[response objectForKey:#"photoset"] objectForKey:#"id"];

Answer 2

Make sure that you perform the nsjsonserialization in the
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
method.
You need to create a instance variable in the #interface like this:
#interface TheClass: NSObject<NSURLConnectionDelegate>
{
NSMutableData *_responseData;
}
And then fetch the data this way:
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
// Append the new data to the instance variable you declared
[_responseData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSError *error;
NSDictionary *response = [NSJSONSerialization JSONObjectWithData:_responseData options:NSJSONReadingMutableContainers error:&error];
}
All data hasn't been receieved until the connectionDidfinishLoading method is executed.