Question

I am using the Google Directions iOS API. I am getting the data using JSON instead of XML. But I am using AFNetworking to simplify this for me. AFNetworking is available at github. Right now, I am able to display an overlay route from one location to another on an MKMapView. Here is my code:

// AFNETWORKING ==========================================================

        AFHTTPClient *_httpClient = [AFHTTPClient clientWithBaseURL:[NSURL URLWithString:@"http://maps.googleapis.com/"]];

    [_httpClient registerHTTPOperationClass: [AFJSONRequestOperation class]];

    [_httpClient setDefaultHeader:@"Accept" value:@"application/json"];

    NSMutableDictionary *parameters = [[NSMutableDictionary alloc] init];

    [parameters setObject:[NSString stringWithFormat:@"%f,%f", location.coordinate.latitude, location.coordinate.longitude] forKey:@"origin"];

    [parameters setObject:[NSString stringWithFormat:@"%f,%f", location2.coordinate.latitude, location2.coordinate.longitude] forKey:@"destination"];

    [parameters setObject:@"false" forKey:@"sensor"];

    [parameters setObject:@"driving" forKey:@"mode"];

    [parameters setObject:@"metric" forKey: @"units"];

    NSMutableURLRequest *request = [_httpClient requestWithMethod:@"GET" path: @"maps/api/directions/json" parameters:parameters];

    request.cachePolicy = NSURLRequestReloadIgnoringLocalCacheData;

    AFHTTPRequestOperation *operation = [_httpClient HTTPRequestOperationWithRequest:request success:^(AFHTTPRequestOperation *operation, id responseObject) {

        NSInteger statusCode = operation.response.statusCode;

        if (statusCode == 200) {

            [self parseResponse:responseObject];

        } else {

        }

    } failure:^(AFHTTPRequestOperation *operation, NSError *error) { }];

    [_httpClient enqueueHTTPRequestOperation:operation];

// ROUTE SETUP AND RESPONSE RECIEVED METHOD ==========================================================


- (void)parseResponse:(NSDictionary *)response {

NSArray *routes = [response objectForKey:@"routes"];

NSDictionary *routePath = [routes lastObject];

if (routePath) {

    NSString *overviewPolyline = [[routePath objectForKey: @"overview_polyline"] objectForKey:@"points"];

    NSLog(@"Status: %@", [response objectForKey: @"status"]);

    NSLog(@"Legs: %@", [routePath objectForKey: @"legs[]"]);

    _path = [self decodePolyLine:overviewPolyline];

    NSInteger numberOfSteps = _path.count;

    CLLocationCoordinate2D coordinates[numberOfSteps];
    for (NSInteger index = 0; index < numberOfSteps; index++) {
        CLLocation *location = [_path objectAtIndex:index];
        CLLocationCoordinate2D coordinate = location.coordinate;

        coordinates[index] = coordinate;
    }

    polyLine = [MKPolyline polylineWithCoordinates:coordinates count:numberOfSteps];
    [self.mapView addOverlay:polyLine];
}

}

This is the main code to get the route functioning. And it works well! But now what I want to do is get direction list and complete duration and summary. So I took a deep look at Google Directions API Documentation and it tells me to use its different dictionaries and arrays and objects. But I have had no luck. I get a status of OK. When I log the count of the routes array, its only one object. Then the MOST important, legs[] array is NULL.

    NSLog(@"Legs is: %@", [routePath objectForKey: @"legs[]"]);

Output:

Legs is (null)

Legs[] includes everything important like the direction list and duration. Summary is not NULL, it gives the name of one of the streets that the route bypasses. I dont know how that is a summary. Might be because there is only one object in the routes array. waypoint_order and warnings[] are NULL too. bounds and of course overview_polyline are valid, thats how I got the route working.

So whats the problem here? Why are so many of the objects Google Directions API provides NULL when I need them?

Thanks!

Answer 1

Alright, the problem was that the response for directions was taking too long. I expected the legs[] response to instantly deliver along with the overview_polyline. So I just had to wait till the response came in, this gives me an opportunity to insert a buffer UI.