iOS 9 Best solution for parsing JSON - ios

Question

I always used this solution when I needed to parse a feed JSON.
https://stackoverflow.com/a/20077594/2829111
But sendAsynchronousRequest is now deprecated and I'm stuck with this code
__block NSDictionary *json;
[[session dataTaskWithURL:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
// handle response
json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
NSLog(#"Async JSON: %#", json);
[collectionView reloadData];
}] resume];
And with this the reloadData argument takes a long time to execute. I've alredy tried forcing back to the main queue with:
__block NSDictionary *json;
[[session dataTaskWithURL:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
// handle response
json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
NSLog(#"Async JSON: %#", json);
dispatch_sync(dispatch_queue_create("com.foo.samplequeue", NULL), ^{[collectionView reloadData});
}] resume];

Answer 1

The problem is that the completion handler does not run on the main queue. But all UI updates must happen on the main queue. So dispatch that to the main queue:
[[session dataTaskWithURL:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
// handle response
NSError *parseError;
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:&parseError];
// do something with `json`
dispatch_async(dispatch_get_main_queue()), ^{[collectionView reloadData]});
}] resume];

Answer 2

Why don't you try JSONModel library....... it is so simple to use
-(void)getEmployeePerformance:(EmpPerformanceRequest*)request
withSuccesBlock:(succesEmployeePerformanceResponseBlock) successBlock
andFailBlock:(FailResponseBlock) failBlock
{
NSString* weatherUrl = [[ABWebServiceUtil sharedInstance]getEmployeePerformanceURL];
[HTTPClientUtil postDataToWS:weatherUrl parameters:[request toDictionary] WithHeaderDict:nil withBlock:^(AFHTTPRequestOperation *responseObj, NSError *error)
{
if(responseObj.response.statusCode == HTTP_RESPONSE_SUCESS)
{
EmpPerformanceArrayModel *empPerfArrModel;
if(responseObj.responseString)
{
empPerfArrModel = [[EmpPerformanceArrayModel alloc]initWithString:result error:nil];
empPerfArrModel.employeesArray = [empPerformanceModel arrayOfModelsFromDictionaries:empPerfArrModel.employeesArray];
}
if(successBlock)
{
successBlock(responseObj.response.statusCode, empPerfArrModel);
}
}else if (failBlock)
{
failBlock(responseObj.response.statusCode);
}
}];
}
for more detail follow this link...... it will brief you well
https://github.com/icanzilb/JSONModel

Answer 3

Try parsing JSON in connectionDidFinishLoading so you will get response as NSDictionary.
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
Class NSJSONSerializationclass = NSClassFromString(#"NSJSONSerialization");
NSDictionary *result;
NSError *error;
if (NSJSONSerializationclass)
{
result = [NSJSONSerialization JSONObjectWithData: responseData options: NSJSONReadingMutableContainers error: &error];
}
// If the webservice response having values we have to call the completionBlock…
if (result)
{
if (self.completionBlock != nil)
{
self.completionBlock(result);
}
}
}