Get values out of data from NSJSONSerialization - ios

Question

I have some JSON data which is pulled from a URL. The code I have written works fine to download the JSON and parse it, but I cannot seem to access it how I need too, especially where the data is contained as a sub-element of another one.
Here is the JSON format:
{
address = "<null>";
city = "<null>";
country = UK;
"country_code" = GB;
daylight = 1;
for = daily;
items = (
{
asr = "5:22 pm";
"date_for" = "2013-7-1";
dhuhr = "1:01 pm";
fajr = "2:15 am";
isha = "11:47 pm";
maghrib = "9:24 pm";
shurooq = "4:39 am";
}
);
latitude = "50.9994081";
link = "http://muslimsalat.com/UK";
longitude = "0.5039011";
"map_image" = "http://maps.google.com/maps/api/staticmap?center=50.9994081,0.5039011&sensor=false&zoom=13&size=300x300";
"postal_code" = "<null>";
"prayer_method_name" = "Muslim World League";
"qibla_direction" = "119.26";
query = "51.000000,0.500000";
state = "<null>";
timezone = 0;
title = UK;
"today_weather" = {
pressure = 1020;
temperature = 14;
};
}
(These are Islamic prayer times.)
My Objective-C so far is this:
-(CLLocationCoordinate2D) getLocation{
CLLocationManager *locationManager = [[[CLLocationManager alloc] init] autorelease];
locationManager.delegate = self;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.distanceFilter = kCLDistanceFilterNone;
[locationManager startUpdatingLocation];
CLLocation *location = [locationManager location];
CLLocationCoordinate2D coordinate = [location coordinate];
return coordinate;
}
//class to convert JSON to NSData
- (IBAction)getDataFromJson:(id)sender {
//get the coords:
CLLocationCoordinate2D coordinate = [self getLocation];
NSString *latitude = [NSString stringWithFormat:#"%f", coordinate.latitude];
NSString *longitude = [NSString stringWithFormat:#"%f", coordinate.longitude];
NSLog(#"*dLatitude : %#", latitude);
NSLog(#"*dLongitude : %#",longitude);
//load in the times from the json
NSString *myURLString = [NSString stringWithFormat:#"http://muslimsalat.com/%#,%#/daily/5.json", latitude, longitude];
NSURL *url = [NSURL URLWithString:myURLString];
NSData *jsonData = [NSData dataWithContentsOfURL:url];
if(jsonData != nil)
{
NSError *error = nil;
id result = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:&error];
NSArray *jsonArray = (NSArray *)result; //convert to an array
if (error == nil)
NSLog(#"%#", result);
NSLog(#"%#", jsonArray);
for (id element in jsonArray) {
NSLog(#"Element: %#", [element description]);
}
}
}
When running this code, the only output I get is a list of element names (address, city, country, so on). items is given, but not its child elements. I understand that this is what I am asking the code for with:
for (id element in jsonArray) {
NSLog(#"Element: %#", [element description]);
}
but I do not know how to move onto the next step.
The only data values which I require are in fact the times themselves (so, items>asr, items>dhuhr, etc).
How can I get these values themselves and then save them as values I can work with?
Thank you!

Answer 1

(...); - is Array
{...}; - is Dictionary
so your "element" is Dictionary
use objectForKey:
example:
for (id element in jsonArray) {
NSLog(#"Element asr: %#", [element objectForKey:#"asr"]); // or element[#"asr"]
}

Answer 2

NSArray *jsonArray = (NSArray *)result; //convert to an array
This doesn't 'convert', it's just you promising the compiler that result is really an NSArray. And in this case it's a lie.
Your code is currently just printing a list of the keys in the dictionary that is returned in the JSON. Try this to get to the list of items (it's an array so you need to deal with there possibly being multiple entries):
NSDictionary *result = [NSJSONSerialization ...
for (NSDictionary *itemDict in result[#"items"]) {
NSLog(#"item: %#", itemDict);
}
Then you can extract the times.

Answer 3

You can extract info by following:
NSError* error = nil;
NSDictionary *userInfo; //your main data
if([NSJSONSerialization class])
userInfo = [NSJSONSerialization JSONObjectWithData:[request responseData] options:kNilOptions error:&error];
//to extract items
NSDictionary *items = [[[userInfo objectForKey:#"items"] JSONValue] objectAtIndex:0];