How to decode route points from the JSON Output Data? - ios

Question

I am new in the ios field, Now i am trying to implement MKMapView Based iPhone Application. From the Google Map Web web service i Fetch the Data in JSON Output Format.
- (void)update {
self.responseData=[NSMutableData data];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:#"http://maps.googleapis.com/maps/api/directions/json?origin=Ernakulam&destination=Kanyakumari&mode=driving&sensor=false"]];
[[NSURLConnection alloc] initWithRequest:request delegate:self];
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
[self.responseData setLength:0];
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
[self.responseData appendData:data];
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
[connection release];
self.responseData =nil;
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSLog(#"connection established");
[connection release];
NSString *responseString=[[NSString alloc]initWithData:self.responseData encoding:NSUTF8StringEncoding];
self.responseData=nil;
NSLog(#" OUTPUT JSON DATA^^^^^^^^^^^^^^^^%#",responseString);
}
I got the out put has in the JSON Format. Now i want to draw route between this two location. sow how can i separate all the latitude and Longitude points from the JSON out put Data.

Answer 1

Check out this code. I am using JSONkit for parsing
-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSLog(#"connection established");
[connection release];
NSString *responseString=[[NSString alloc]initWithData:responseData encoding:NSUTF8StringEncoding];
NSMutableDictionary *data1 = [responseData objectFromJSONData];
NSMutableArray *ad = [data1 objectForKey:#"routes"];
NSMutableArray *data2 = [[ad objectAtIndex:0] objectForKey:#"legs"];
NSMutableArray *data3 = [[data2 objectAtIndex:0] objectForKey:#"steps"];
// NSLog(#"Data3 %#", data3);
for(int i = 0; i<data3.count;i++){
NSLog(#"Start %#", [[data3 objectAtIndex:i] objectForKey:#"start_location"]);
NSLog(#"End %#", [[data3 objectAtIndex:i] objectForKey:#"end_location"]);
}
}

Answer 2

I am using SBJson to parse json data.
In general, call [responseString JSONValue] to get parsed data.
You can google it for detail reference.