I'm trying to get local matchmaking working in GameKit using [[GKMatchmaker sharedMatchmaker] startBrowsingForNearbyPlayersWithReachableHandler:]. Essentially, I'm trying to implement interface-less local matches: as long as there's a player in my local vicinity, I want to connect and start a match. Importantly, I only want to do this for local players: I never want to match automatically over the internet.
I've enabled Game Center for my app in iTunes connect and signed up for a different sandbox account on every device I'm using to test.
I've tried both matchmaking with GKMatchmakerViewController (after authenticating the local player) and programmatic matchmaking with startBrowsingForNearbyPlayersWithReachableHandler:, running the same code on an iPhone 4 and an 4th gen iPod Touch sitting next to each other on my desk. Neither ever finds the other; when using GKMatchmakerViewController the interface for finding nearby players remains at the
Finding Players...
spinner, and when using startBrowsingForNearbyPlayersWithReachableHandler:, the notification block never gets called.
Here's my current block of testing code:
-(void)connectLocal
{
if( ![GKLocalPlayer localPlayer].isAuthenticated )
{
// authenticateLocalPlayer calls connectLocal again after authentication is complete
[ self authenticateLocalPlayer ];
return;
}
[[GKMatchmaker sharedMatchmaker] startBrowsingForNearbyPlayersWithReachableHandler:^(NSString *playerID, BOOL reachable) {
NSLog(#"Reachability changed for player %#", playerID );
} ];
}
The docs are a little sparse & confusing on the subject, especially when it comes to the difference between local mulitplayer and matches over the internet. For instance, it seems to be necessary to authenticate the local player and create a match before finding players to join that match (Creating Any Kind of Match Starts with a Match Request). However this little nugget seems to suggest otherwise:
The standard user interface allows players to discover other nearby players, even when neither player is currently connected to Game Center directly.
Additionally, in the flow described in Searching For Nearby Players, a match request isn't created until step 3, after finding players via the notification block passed to startBrowsingForNearbyPlayersWithReachableHandler:. Unfortunately, I've never got that far.
So, the questions:
1) Am I right in thinking I can call startBrowsingForNearbyPlayersWithReachableHandler: before authenticating the local player? GameKit doesn't throw an error, so I'm assuming it's OK. This may be a rash assumption. Whether I authenticate or not doesn't seem to make much difference.
2) Has anyone successfully implemented local auto-matching using [GKMatchmaker sharedMatchmaker] startBrowsingForNearbyPlayersWithReachableHandler:? Is there good example code anywhere that illustrates the complete flow, from browsing for players to starting a match, all programmatically?
3) There seem to be conflicting reports on the web over whether GameKit-enabled apps can be tested in the iOS Simulator. General consensus seems not, and it's better to test on iOS hardware. I've been using a iPhone 4 & an 4th gen iPod Touch. For those who have successfully tested local multiplayer, what testing setup & methodology did you use?
1) Am I right in thinking I can call startBrowsingForNearbyPlayersWithReachableHandler: before authenticating the local player?
No. startBrowsingForNearbyPlayersWithReachableHandler works by both advertising the existing player and browsing for other players but, most importantly, the information it uses to identify players is the playerID... which won't be available until the player authenticates.
3) There seem to be conflicting reports on the web over whether GameKit-enabled apps can be tested in the iOS Simulator. General consensus seems not, and it's better to test on iOS hardware
GameCenter authentication, achievements, and leaderboards work in the simulator, everything else should be tested on real hardware. I actually recommend the simulator for authentication testing, since it avoids the sandbox/production switch which can make detailed auth testing on devices somewhat confusing. Everything else can only be tested on devices. The simulator doesn't have great support for receiving push notifications which breaks match setup and the general hardware configuration is different enough that match communication isn't unlikely to work right anyway.
You need to do these things in this order:
Authenticate the local player
Install an invite handler
Start browsing for nearby players
Authentication is required - this registers your app with Game Center and logs the player in. In most cases, you won't even need internet access to do this.
Installing the invitation handler is also required, and I think this is the step you're missing. This lets your app know what to do when an inbound invitation is received. If you don't do this, a device won't register as being nearby.
Only start browsing once you've done the above two.
Here's some sample code to get you going. Call this method after the app launches:
- (void) authenticateLocalPlayer
{
static BOOL gcAuthenticationCalled = NO;
if (!gcAuthenticationCalled) {
GKLocalPlayer *localPlayer = [GKLocalPlayer localPlayer];
void (^authenticationHandler)(UIViewController*, NSError*) = ^(UIViewController *viewController, NSError *error) {
NSLog(#"Authenticating with Game Center.");
GKLocalPlayer *myLocalPlayer = [GKLocalPlayer localPlayer];
if (viewController != nil)
{
NSLog(#"Not authenticated - storing view controller.");
self.authenticationController = viewController;
}
else if ([myLocalPlayer isAuthenticated])
{
NSLog(#"Player is authenticated!");
//iOS8 - register as a listener
[localPlayer unregisterAllListeners];
[localPlayer registerListener:self];
[[GKLocalPlayer localPlayer] loadFriendPlayersWithCompletionHandler:^(NSArray *friendPlayers, NSError *error) {
//Do something with the friends
}];
//iOS7 - install an invitation handler
[GKMatchmaker sharedMatchmaker].inviteHandler = ^(GKInvite *acceptedInvite, NSArray *playersToInvite) {
// Insert game-specific code here to clean up any game in progress.
if (acceptedInvite)
{
//This player accepted an invitation.
//If doing programmatic matchmaking, call GKMatchmaker's matchForInvite:completionHandler
//to get a match for the invite. Otherwise you need to allocate a GKMatchmakerViewController
//instance and present it with the invite.
}
else if (playersToInvite)
{
//Your game was launched from the GameCenter app to host a match.
}
};
//Now you can browse. Note this is the iOS8 call. The iOS7 call is slightly different.
[[GKMatchmaker sharedMatchmaker] startBrowsingForNearbyPlayersWithHandler:^(GKPlayer *player, BOOL reachable) {
NSLog(#"Player Nearby: %#", player.playerID);
}];
}
else
{
//Authentication failed.
self.authenticationController = nil;
if (error) {
NSLog([error description], nil);
}
}
};
localPlayer.authenticateHandler = authenticationHandler;
gcAuthenticationCalled = YES;
}
}
* IMPORTANT *
If you're using iOS8, you don't install the invitation handler. You instead register an object as listening for the protocol GKLocalPlayerListener, and implement these methods:
-player:didAcceptInvite:
-player:didRequestMatchWithRecipients:
If you don't implement these methods on iOS8, it won't work!
You then link GKMatchmaker to that object by calling this after authenticating the local player:
[localPlayer registerListener:self];
Make sure the object that's implementing the protocol is declared like so in the .h file:
#interface MyImplementingObject : NSObject <GKMatchDelegate, GKLocalPlayerListener>
If you do all this and it still isn't working, make sure that you have your bundle ID set correctly in your app (Click the app, click 'Targets', make sure Bundle Identifier and Version are filled in), then click the 'Capabilities' tab (XCode 6), and make sure Game Center is on.
Go to the Member Center and make sure that the app using that bundle ID also has Game Center enabled for its Provisioning Profile. Download and reapply your Provisioning Profile if necessary.
Make sure the sandbox switch is ON in your Settings under GameCenter, and also make sure that 'Allow Invites' and 'Nearby Players' switches are turned ON.
Finally, make sure you go to iTunes Connect and verify that Game Center is enabled for your app there as well.
So, keep in mind the differences between iOS7 and iOS8. This code will work on either version and call 'updateNearbyPlayer' in turn.
if ( IS_IOS8 )
{
[[GKMatchmaker sharedMatchmaker] startBrowsingForNearbyPlayersWithHandler:^(GKPlayer *gkPlayer, BOOL reachable)
{
NSLog(#"PLAYER ID %# is %#",gkPlayer.playerID,reachable?#"reachable" : #"not reachable");
[self updateNearbyPlayer:gkPlayer reachable:reachable];
}];
} else {
/*
* iOS 7...
*/
[[GKMatchmaker sharedMatchmaker] startBrowsingForNearbyPlayersWithReachableHandler:^(NSString *playerID, BOOL reachable)
{
NSLog(#"PLAYER ID %# is %#",playerID,reachable?#"reachable" : #"not reachable");
[GKPlayer loadPlayersForIdentifiers:#[playerID] withCompletionHandler:^(NSArray *players, NSError *error) {
NSLog(#"Loaded: %#, error= %#",players,error);
GKPlayer *gkPlayer = [players objectAtIndex:0];
[self updateNearbyPlayer:gkPlayer reachable:reachable];
}];
}];
}
With some delay due to the underlying Bonjour services, this mechanism works great. However, it needs to be balanced with an appropriate call to:
[[GKMatchmaker sharedMatchmaker] stopBrowsingForNearbyPlayers];
Whenever you use one of the GKPlayers/PlayerIDs reported to establish a match or to add it to an existing match, you should stop browsing. Once the match has been finished, closed or cancelled, start browsing again. Otherwise, on the second attempt to connect to a nearby device, you'll fail.
Related
I am working on the iPhone app in Objective-C in which I count steps of user by using CMAccelerometerData.
It works fine when app is running in background ,
But when I kill my app (double-clicking the Home button and then swiping app away) then I can not get the steps count.
The feature of app is that fetch steps count if my app is in kill state (double-clicking the Home button and then swiping app away) and I run it from icon.
Is there any way to get steps count if our app is killed (double-clicking the Home button and then swiping app away) ?
Here is the method to get steps
- (void)startDetectionWithUpdateBlock:(void (^)(NSError *))callback
{
if (self.motionManager.isAccelerometerActive) {
return;
}
[self.motionManager startAccelerometerUpdatesToQueue:self.queue withHandler:^(CMAccelerometerData *accelerometerData, NSError *error) {
if (error) {
if (callback) {
dispatch_async(dispatch_get_main_queue(), ^{
callback (error);
});
}
return ;
}
CMAcceleration acceleration = accelerometerData.acceleration;
CGFloat strength = 1.2f;
BOOL isStep = NO;
if (fabs(acceleration.x) > strength || fabs(acceleration.y) > strength || fabs(acceleration.z) > strength) {
isStep = YES;
}
if (isStep) {
if (callback) {
dispatch_async(dispatch_get_main_queue(), ^{
callback (nil);
});
}
}
}];
}
And through this way I update steps count :
[[SOLocationManager sharedInstance] start];
[[SOStepDetector sharedInstance] startDetectionWithUpdateBlock:^(NSError *error) {
if (error) {
NSLog(#"%#", error.localizedDescription);
return;
}
self.actualCheckpoint.stepsCount ++;
NSLog(#"Total Steps: %ld",(long)self.actualCheckpoint.stepsCount);
[[NSNotificationCenter defaultCenter] postNotificationName:SBCompetitionStepsCountDidChange object:self.actualCheckpoint];
}];
you can catch the data in appDelegate's
- (void)applicationWillTerminate:(UIApplication *)application {}
You can't access HealthKit data in the background when the device is locked, according to Apple:
For security, the HealthKit store is encrypted when the device is locked. The HealthKit store can only be accessed by an authorized app. As a result, you may not be able to read data from the store when your app is launched in the background; however, apps can still write data to the store, even when the phone is locked. HealthKit temporarily caches the data and saves it to the encrypted store as soon as the phone is unlocked.
https://developer.apple.com/library/ios/documentation/HealthKit/Reference/HealthKit_Framework/
You'll need to read the data on startup to 'catch up' from the last time your app was run.
If the app is killed by the user by swiping up, rather than by simply putting the app into the background, it is no longer allows to execute any code until the user opens it again. However, there's no way to get direct access to the accelerometer if the app is completely killed.
There are ways to handle keeping the app open indefinitely if it goes into the background (not manually killed by the user). However, having the accelerometer powered up constantly would be a significant battery drain, and if all you want to do it track steps, you can simply use the HealthKit API. (If you need your app to work on old devices, you will have to resort to background processing.)
HealthKit
As an Apple OS-level API, HealthKit is always working and (if the user's device supports it and the user hasn't disabled it) is constantly tracking steps in the background, using Apple's accurate, battery efficient algorithm (it uses the device's motion coprocessor).
All you need to do is integrate your app with HealthKit such that it can read the device's Steps metric. Take a look at this objective-C tutorial.
I'm implementing GameCenter for my game. I followed tutorials and created my ids for leaderboards and achievements.
Authenticating and achievements are working well. But GameCenter does not show scores for my levels.
I'm using the code below for sending score to GameCenter servers. Sending operation always returns success. But score not showing up.
GKScore *scoreReporter = [[GKScore alloc] initWithLeaderboardIdentifier: identifier];
scoreReporter.value = score;
scoreReporter.context = 0;
[GKScore reportScores:#[scoreReporter] withCompletionHandler:^(NSError *error) {
if (error == nil) {
NSLog(#"Score reported successfully!");
} else {
NSLog(#"Unable to report score!");
}
}];
I've read some of the other threads and they are not consistent enough. My ids right and the code is working well. With iOS 9 sandbox option is not available. So selecting sandbox from device's settings is not the issue.
Some of the reasons I can think of from my research why it is not working are these;
Scores will take time to sync (It has been 5 hours since my first try)
Small scores might not be sent to server sometimes (this is a very silly bug if this is happening but it was mentioned in the other threads)
Some kind of problem with testing (It's not the issue I think because achievements is working)
Any help will be appreciated.
After a day passed it started working. It think I had bad luck about the time passed this shouldn't be that long.
I have implemented GameKit with achievements and leaderboards in my game.
I've tested both and they seem to work.
But in order to test them correctly from the beginning (I did some tests by trials and errors) is there any way to start again completely erasing both?
I tried deleting the app form the GameCenter app of the simulation/phone but when I login again and iOS register the app in GameCenter everything re-appears.
Furthermore I implemented one achievement that can be achieved more than ones. This achievement gives 50 points. Actually I can achieve it more than ones in the game in fact I get the pop-up each time. However in the achievement list I can only see 50 points and not more, possible?
Perhaps, I didn't get the meaning of achievable more than ones..
EDIT:
I'm trying to solve this with the following method
func resetAchievements() {
// Clear all progress saved on Game Center
GKAchievement.resetAchievementsWithCompletionHandler() {(error) in
self.lastError = error
}
}
But it works only when I install the app in the device and not in the Simulator, why?
Perhaps because I don't understand the Apple's Guide
class func resetAchievementsWithCompletionHandler(_ completionHandler: ((NSError!) -> Void)!)
The following will reset all the achievements your local player has earned. You cannot earn an achievement more than once, what you are doing is posting the final value over and over again which is showing you the completion alert. The earned more than once option allows you to accept challenges from friends on that achievement. I recommend reading the introduction guide again as both of these topics are discussed in detail.
[GKAchievement resetAchievementsWithCompletionHandler: ^(NSError *error)
{
if(error == NULL)
{
NSLog(#"Achievements have been reset");
}
else
{
NSLog(#"There was an error in resetting the achievements: %#", [error localizedDescription]);
}
}];
I am working on a new version of my app. I was using the sandbox normally for a while, but now all of my devices are stuck with a very strange problem. They appear to be halfway logged into game center. It doesn't work for them, but they can't log out either. Here is my authentication method:
- (void)authenticateLocalPlayer {
GKLocalPlayer* localPlayer = WJLocalPlayer;
WJLog(#"Authenticating local user...");
if (localPlayer.authenticated == NO) {
localPlayer.authenticateHandler = ^ (UIViewController* vc, NSError *error) {
if (error) {
WJLog(#"Authentication failed! %#", [error localizedDescription]);
}
else {
WJLog(#"Authentication succeeded!");
NSString* name = [GKLocalPlayer localPlayer].displayName;
WJLog(#"display name is %#", name);
NSString* alias = [GKLocalPlayer localPlayer].alias;
WJLog(#"alias is %#", alias);
GKTurnBasedEventHandler *ev = [GKTurnBasedEventHandler sharedTurnBasedEventHandler];
ev.delegate = self;
}
};
}
}
And here is what I am seeing from the log statements [WJLog is just my own version of NSLog without the garbage]:
Authenticating local user...
Authentication succeeded!
display name is Me
alias is (null)
I can log in or out in the game center app. It makes no difference. I always see the above. I even tried restoring one of the devices to factory settings. The result was still the same. I also tried disabling and re-enabling game center for the new version of my app. Still the same result.
Any ideas?
You're completely ignoring the UIViewController parameter. You're supposed to present this to the user if it exists, so they can log in. Probably you are only now experiencing this because you logged in to the non-sandbox game center, and now when you run the app it wants to ask you for your sandbox credentials, but instead you're assuming you're authenticated.
You have some other problems here too:
You should set the authenticateHandler once only, soon after your app launches.
You should check localPlayer.authenticated inside your authenticateHandler, and nowhere else, as this is the only place it's guaranteed to be valid. Specifically, it's a meaningless value after you resume from the background and until your authenticateHandler gets called again. If you need it elsewhere, use a global variable that gets initialised to false at startup and also in your applicationWillEnterForeground method, and only gets set to true inside your authenticateHandler when you've determined that the localPlayer is actually authenticated.
Check the error and log it by all means, but it doesn't tell you anything about whether authentication actually succeeded, so remove the 'else'.
Have a look at the documentation here.
So far I have had success in implementing Game Center for my app. Authorizing players is OK, so is reporting Achievements.
My issue is when I wanted to test app behavior with my iPad in flight mode.
The player will not get authorized (as I expected, so no issue) with this code.
GKLocalPlayer *localPlayer = [GKLocalPlayer localPlayer];
if ([localPlayer isAuthenticated] == YES){
NSLog(#"The local player has already authenticated.");
return;
} else {
[localPlayer authenticateWithCompletionHandler:^(NSError *error) {
if (error == nil){
NSLog(#"Successfully authenticated the local player.");
NSLog(#"Player Alias = %#", [localPlayer alias]);
} else {
NSLog(#"Failed to authenticate the player with error = %#", error);
}
}];
}
But when I later on in a UIView check if the player is authorized (so I know if I shall enable my show achievement button) with this code [achievementButton setEnabled:[localPlayer isAuthenticated]];I always get a YES as long as a user was logged in to Game Center before entering Flight Mode.
It seems like even if there is no connection to Game Center servers a previous authorized player is still seen as authorized.
This leads to that my button is shown but of course Game Center reports that it can not connect.
So, what would be the best way to check that a true connection to Game Center is available?
Cheers
I don't think there is an API to check that, but you can always make a call to one of the API that is going to return results, like getting leaderboards. It will fail if you're not connected.
Have a look at the SCNetworkReachability interfaces. Search in the docs for SCNetworkReachability, and there are other SO questions that reference this. Basically, you can use the Reachability APIs to continuously keep updated a flag that you can check to know whether or not you have a network connection.