Elevation

cf Google Geocoding API page for the behaviour of the WS.

How to use

Retrieve elevation for location(s):

afGMapsElevationRequest *req = [afGMapsElevationRequest request];
req.afDelegate = self;
[req addLocation:[ [ CLLocation alloc ] initWithLatitude:11.22 longitude:11.33 ] ];
[req addLocation:[ [ CLLocation alloc ] initWithLatitude:11.21 longitude:11.34 ] ];
[req setUseSensor:YES];

[req startAsynchronous];

Or to reverse geocode coordinates:

afGMapsElevationRequest *req = [afGMapsElevationRequest request];
req.afDelegate = self;
[req addPathPoint:[ [CLLocation alloc] initWithLatitude:11.22 longitude:11.33]];
[req addPathPoint:[ [CLLocation alloc] initWithLatitude:11.90 longitude:11.10]];
req.pathNumber = 100 ; //will return 100 samples 
[req setUseSensor:YES];

[req startAsynchronous];

Then, simply make your class inherit the afGoogleMapsElevationDelegate protocol, and implement the following delegate functions (all optional):

-(void) afElevationWSStarted:(afGMapsElevationRequest *)ws ;

-(void)  afElevationWSFailed:(afGMapsElevationRequest *)ws withError:(NSError *)er;

-(void)  afElevationWS:(afGMapsElevationRequest *)ws gotElevation:(NSNumber *)elevation forLocation:(CLLocation *)location;

The array returned by the following delegate contains dictionnaries holding the results available. They have the same structure as the ones returned by Google Web Services:

{
   "location": {
      "lat": 39.7391536,
      "lng": -104.9847034
    },
    "elevation": 1608.8402100
}

-(void)  afElevationWS:(afGMapsElevationRequest *)ws gotResults:(NSArray *) results;