Game Center and Social Media - Beginning iOS6 Games Development - page 226

Figure 9-11. First achievement in the Game Center app
In Figure 9-11 , we see a screenshot from the Game Center app displaying the achievements for Belt
Commander. We can see that the achievement in this view was awarded. Listing 9-5 shows the code
that awards the achievement.
Listing 9-5. BeltCommanderController.m (checkAchievements)
-(void)checkAchievements{
if (asteroids_destroyed >= 10){
GKAchievement* achievement = [[GKAchievement alloc]
initWithIdentifier:@"beltcommander.10asteroids"];
achievement.percentComplete = 100.0;
[achievement reportAchievementWithCompletionHandler:^(NSError *error) {
if (error){
// report error
}
}];
}
}
In Listing 9-5, we see the task checkAchievements from the class BeltCommanderController ,
which is responsible for handling the in-play game logic. The first thing we do is check if the
asteroids_destroyed is bigger or equal to 10. The variable asteroids_destroyed is simply
incremented whenever an asteroid in the game is destroyed. If asteroids_destroyed is at least 10,