Device Token and Push Notification - iphone

Question

I am trying to implement Push Notifications into my app, but I have, what I believe, may be a dumb question. I have my Push Notifications working, but they work because I am putting the Device Token into my asp.net code on the server.
My question is, am I supposed to keep track of the device tokens my app obtains? In other words, when the app launches and I get the device token, do I need to send those up to my server and store them so that when I need to send a notification to all the users of my App i can go through the list of tokens and send the notification to each device token?
Thanks for any clarity you can bring, as you guessed this is my first attempt at Push Notifications.

Answer 1

You have to store the device tokens in a database. Then you send a notification addressed to each device token. You can create the system by yourself, but there are open source libraries that have done this already. Although it is for PHP, Easy APNS is an example.

Answer 2

I'd run into this scenario myself, as it turns out hardcoding device tokens is one way to limit the devices which can be sent push notifications but if you wanted to allow any device who has downloaded your app you need to create a mechanism to send the device's device token to your server so that a push notification is sent to it. You could setup this request to your server on app load, and in my case silently succeed and on failure let the user know that they were not added to the notification list.
Here's an example from raywenderlich.com that creates a chat program. -- basically they are creating a post request with device info that they are storing in a database, and later accessing the DB info to iterate through and send out the notification.
Some relevant code:
- (void)postJoinRequest
{
MBProgressHUD* hud = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
hud.labelText = NSLocalizedString(#"Connecting", nil);
NSURL* url = [NSURL URLWithString:ServerApiURL];
__block ASIFormDataRequest* request = [ASIFormDataRequest requestWithURL:url];
[request setDelegate:self];
[request setPostValue:#"join" forKey:#"cmd"];
[request setPostValue:[dataModel udid] forKey:#"udid"];
[request setPostValue:[dataModel deviceToken] forKey:#"token"];
[request setPostValue:[dataModel nickname] forKey:#"name"];
[request setPostValue:[dataModel secretCode] forKey:#"code"];
[request setCompletionBlock:^
{
if ([self isViewLoaded])
{
[MBProgressHUD hideHUDForView:self.view animated:YES];
if ([request responseStatusCode] != 200)
{
ShowErrorAlert(NSLocalizedString(#"There was an error communicating with the server", nil));
}
else
{
[self userDidJoin];
}
}
}];
[request setFailedBlock:^
{
if ([self isViewLoaded])
{
[MBProgressHUD hideHUDForView:self.view animated:YES];
ShowErrorAlert([[request error] localizedDescription]);
}
}];
[request startAsynchronous];
}