Parsing JSON Help IOS - ios

Question

I currentley have a jSON file which is created a by a script which can be seen here: http://ddelay.co.uk/bus/output.json
I currently have managed to setup the following to grab the JSON which works, i just cannot figure how to grab the data to assign it :/
-(void)makeStopRequests{
NSURL *url = [NSURL URLWithString:#"http://ddelay.co.uk/bus/output.json"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
//AFNetworking Asynchronous Task
AFJSONRequestOperation *operation = [AFJSONRequestOperation
JSONRequestOperationWithRequest:request
success:^(NSURLRequest *request, NSHTTPURLResponse *response, id responseObject)
{
NSLog(#"JSON RESULT %#", responseObject);
self.stopArray = [responseObject objectForKey:#"stop_name"];
[self.tableView reloadData];
}
failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id responseObject)
{
NSLog(#"Request Failed: %#, %#", error, error.userInfo);
}];
[operation start];
}
I hope somebody can guide me through how I would select the data,
Thank you.
Damien

Answer 1

I would recommend just using something as simple as NSJSONSerialization, which is built into iOS after iOS 5 (may have been earlier, but not too sure).
Just get the data from the request and then parse that into a dictionary with the following code
NSDictionary *dict= [NSJSONSerialization JSONObjectWithData:webData options:NSJSONReadingMutableLeaves error:nil];
get the data using the standard built in networking structure as well
NSURLRequest *someRequest = [[NSURLRequest alloc] initWithURL:someURL cachePolicy:NSURLRequestReloadRevalidatingCacheData timeoutInterval:10.0];
NSURLConnection *someConnection= [[NSURLConnection alloc] initWithRequest:someRequest delegate:self];
And then do whatever appropriate delegation and data processing. Read the documentation to get more details

Answer 2

You are using AFNetworking and it provides you the response object. That is already being cast to Objective c object.
You can simply assign it to NSArray or NSDictionary like this
NSArray *array = (NSArray*)responseObject;//if your json returns an array
NSDictionay *dict (NSDictionary*)responseObject;//if json returns dictionary.
This url returns JSON in this format;
[ {
"service":"22",
"provider":"First in Yorkshire",
"dest":"Nether Edge to Woodhouse",
"dest URL":"/web/public_service_stops.asp?service=22&operatorid=31&systemid=30&goingto=Woodhouse"
},
{
"service":"22",
"provider":"First in Yorkshire",
"dest":"Barnsley to Rotherham",
"dest URL":"/web/public_service_stops.asp?service=22&operatorid=31&systemid=30&goingto=Rotherham"
}
]
Which actually is an array of dictionaries so to access data you have to loop like this.
NSArray *jsonResponse = (NSArray*)responseObject;
for (NSDictionary *dic in jsonResponse){
NSString *service = [dic valueForKey:#"service"];
NSString *provider = [dic valueForKey:#"provider"];
//Same for others
//It will better you create calss with these properties and then add that object to an Array, and on reloading data in table get that object from array in cellForRowAtIndexPath and use requried property to populate your data.
//Or if you just want to use stop name add stop name to array and use it.
NSString *stopName =[dic valueForKey:#"stop_name"];
//[dataArray addObject:stopName]; in case you want to use only stop name
}

Answer 3

Here's minimal code:
self.stopArray = responseObject;
for (NSDictionary *stopDict in self.stopArray) {
NSString *service = [stopDict objectForKey:#"service"];
NSString *provider = [stopDict objectForKey:#"provider"];
NSString *dest = [stopDict objectForKey:#"dest"];
NSString *destURL = [stopDict objectForKey:#"dest URL"];
// do something with this data
}
For anything more complex than this, you'll probably want to make your own data class, so you don't have to parse through dictionaries and arrays in your table view delegate methods.