Question

I’m a bit confused by the documentation. After some research and experimentation, this is what I have.

if ([self canUseMKMapItem]) {
            [self iosTheMap];
        } else {
            [self googleTheMap];
        }

Using this to detect whether we can use the IOS6 mapping features:

- (BOOL) canUseMKMapItem {
    Class itemClass = [MKMapItem class];
    return (itemClass && [itemClass respondsToSelector:@selector(openMapsWithItems:launchOptions:)]);
}

This for IOS5, using Google Maps. It automatically takes us to a screen with a list of directions from the current address (if the user allows) to the destination.

- (void)googleTheMap
{
    NSNumber *userLat = [[NSNumber alloc]initWithDouble:mapView.userLocation.coordinate.latitude];
    NSNumber *userLong = [[NSNumber alloc]initWithDouble:mapView.userLocation.coordinate.longitude];

    NSMutableString *queryString = [NSMutableString stringWithFormat:@"http://maps.google.com/?saddr=%@,%@&daddr=",userLat,userLong];
    NSString *address = [partnerObject valueForKey:ATTRIBUTE_ADDRESS];
    [queryString appendString:address];
    NSString *escaped = [queryString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:escaped]];
}

Here’s the tricky part–this is what I’m trying to do to use Apple Maps

- (void)iosTheMap {
    NSNumber * latitude = [partnerObject valueForKey:ATTRIBUTE_LATITUDE];
    NSNumber * longitude = [partnerObject valueForKey:ATTRIBUTE_LONGITUDE];
    CLLocationCoordinate2D coordinate;
    coordinate.latitude = latitude.doubleValue;
    coordinate.longitude = longitude.doubleValue;
    NSMutableDictionary *addressDictionary = [[NSMutableDictionary alloc] init];
    [addressDictionary setValue:[partnerObject valueForKey:ATTRIBUTE_ADDRESS] forKey:kABPersonAddressStreetKey];
    MKPlacemark *placemark = [[MKPlacemark alloc] initWithCoordinate:coordinate addressDictionary:addressDictionary];
    MKMapItem *mapItem = [[MKMapItem alloc] initWithPlacemark:placemark];
    [mapItem openInMapsWithLaunchOptions:nil];
}

This “works,” sort of. It takes the user to a map screen with a pin showing the address. The user can tap that and get directions. However, I have a few reservations about this approach:

1. I have a compiler warning where I set kABPersonAddressStreetKey: “Incompatible pointer types sending ‘const CFStringRef’ (aka ‘const struct __CFString *const’) to parameter of type ‘NSString *'”
2. The string value I am using is the full address. I use that value for the street address, although the address values are meant to be more atomic–street, city, state. It seems to work, but I’m concerned this isn’t the right way to do it.
3. It would be nice if Apple Maps showed the name of the business/destination, not just the address.
4. It would be great to have Apple Maps automatically show the directions, instead of a map with the destination point, saving the user a few taps.

Any suggestions for how I can improve my approach? Although it seems to work, I suspect that it is not the right way.

Answer 1

You are pretty close. You need to specify the Launch Options dictionary for the openInMapsWithLaunchOptions function using the MKLaunchOptionsDirectionsModeDriving, MKLaunchOptionsDirectionsModeKey value and key.

    Class itemClass = [MKMapItem class];
    if (itemClass && [itemClass respondsToSelector:@selector(openMapsWithItems:launchOptions:)]) {
        // Use iOS 6 maps
        CLLocationCoordinate2D coordinate = [((LocationAnnotation*)[map.annotations objectAtIndex:0]) coordinate];
        MKPlacemark *placemark = [[MKPlacemark alloc] initWithCoordinate:coordinate addressDictionary:nil];
        MKMapItem *mapItem = [[MKMapItem alloc] initWithPlacemark:placemark];
        [mapItem openInMapsWithLaunchOptions:[NSDictionary dictionaryWithObjectsAndKeys:MKLaunchOptionsDirectionsModeDriving, MKLaunchOptionsDirectionsModeKey, nil]];
    } else {
        //Fall back on google
        ...
    }