Programmatically getting directions using Apple Maps - objective-c

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:
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 *'"
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.
It would be nice if Apple Maps showed the name of the business/destination, not just the address.
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
...
}