iPad Application Development For Dummies, 3rd Edition

Implementing the Trip Class

In this chapter, I show you how to implement the Trip model functionality that will enable you to choose between multiple destinations (although you won’t be doing the choosing until Chapter 20). You also implement the Trip functionality that will be needed by the Master View controller (you add that in Chapter 12) — the name of the destination and its background image.

Start by adding the bolded code in Listing 11-1 to Trip.h.

Listing 11-1: Updating the Trip Interface

#import <Foundation/Foundation.h>

#import <mapKit/MapKit.h>

@interface Trip : NSObject

- (id)initWithDestinationIndex:(int)destinationIndex;

- (UIImage *) destinationImage;

- (NSString *) destinationName;

- (CLLocationCoordinate2D) destinationCoordinate;

@end

As you can see, the code in Listing 11-1 contains an initialization method. This method will enable the Trip object to set itself up for the selected destination. (Allow me to explain initialization and a few other things.)

Initialization is the logical place to start, but first you need to add some instance variables and import the Destination header file if you’re going to use it (which you are, in the Trip implementation). Add the bolded code in Listing 11-2 to Trip. m.

Listing 11-2: Updating the Trip Implementation

#import “Trip.h”

#import “Destination.h”

@interface Trip () {

NSDictionary *destinationData;

Destination* destination;

}

@end

@implementation Trip

Now you can add the initWithDestinationIndex: method ...