REST API with JSON in iPhone - objective-c

Question

I want to parse REST API with JSON is there any Best Example or Tutorial so help me...... Like I want to post request like Login and Register and then parse Feed using REST API..... I am using below code to post request
NSString *email = #"*******";
NSString *password = #"******";
NSString *apikey = #"********";
NSString *loginURL = #"***************";
NSURL *url = [NSURL URLWithString:loginURL];
NSString *JSONString = [NSString stringWithFormat:#"{\"apikey\":\"%#\",\"email\":\"%#\",\"password\":\"%#\"}", apikey, email, password];
NSData *JSONBody = [JSONString dataUsingEncoding:NSUTF8StringEncoding];
NSMutableURLRequest *loginRequest = [[NSMutableURLRequest alloc] initWithURL:url];
loginRequest.HTTPMethod = #"POST";
loginRequest.HTTPBody = JSONBody;
NSOperationQueue *queue = [NSOperationQueue new];
[NSURLConnection sendAsynchronousRequest:loginRequest
queue:queue
completionHandler:^(NSURLResponse *response, NSData *data, NSError *error){
NSLog(#"resp:%#",response);
// Manage the response here.
}];

Answer 1

To parse the JSON response, you will need to implement
id obj = [NSJSONSerialization JSONObjectWithData:data];
in your completionHandler.

Answer 2

To get NSDictionary object from server response you may use :
NSDictionary *myDict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error: &error];
After that you can get objects and keys from myDict
The good tutorial you can find here http://www.raywenderlich.com/5492/

Answer 3

Try this
NSDictionary *sampledict = #{#"email":email,#"password":password,#"apikey":apikey};
NSData *dataJson = [NSJSONSerialization dataWithJSONObject:sampledict options:0 error:NULL];
NSMutableURLRequest *loginRequest = [[NSMutableURLRequest alloc] initWithURL:url];
loginRequest.HTTPMethod = #"POST";
loginRequest.HTTPBody = dataJson;
//add these lines
[loginRequest setValue:#"application/json" forHTTPHeaderField:#"Accept"];
[loginRequest setValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
//remaining is the same in your code