Push Notification Help?

Question

Every iPhone user talks about "push notifications". I don't understand exactly what they are in general? I know they are supposed to preserve battery life and all that good stuff... Can someone explain to me how push notifications work and what they are? :) Thanks!

Answer 1

Ok on most other phones like the HTC Touch Pro (Windows Mobile), T-Mobile G1 (android), and Palm Pre (WebOS), they allow you to run apllications like AIM in the background. If you were to do something else, like play a game, the phone would still allow you to recieve IMs instantly. You can have a lot of apps working in the background downside to this, is that your battery drains a lot faster.

Apple decided to bypass all of this by allowing only one application to be opened at a time, and allowing none to run the background. They instead established a "push" server, it compiles all of your IMs e-mails and the like, and sends them out in one burst. Since the iPhone only has to reach out to one place to get all your information, you save battery life. The server will only "push" info to your phone once every 15 to 30 minutes (you can change the settings as you feel fit.) The downside to this is you may not recieve IMs or e-mails as quickly as on other phones. So there's a trade off to each system. Keep in mind though, if you have AIM or your e-mail app open, you'll recieve updates instantly.

Answer 2

Push notification helps send you alerts from an app when it's closed. A good example of this is you are on the AIM app instant messaging and you close out to browse the web. The AIM app is no longer running however push notification will tell you when you have a new instant message so that you can open the app, view the message, and reply. How this saves battery is AIM is not running and is completely closed after you press the home button. This works by using the phones connection to Apple.

Answer 3

Push notification allows an app to notify you of new messages or events without the need to actually open the application, similar to how a text message will make a sound and pop up on your screen. Push notifications are widely used on all mobile devices as a way to inform or update the user.



As a Provider (app developer who sends Push Notifications), you need to set up a server. This server sends a notification to Apple's Push Notification Service (APNS), which then sends the notification to the user's device.



How does the server know which device to send it to? When the user opens your client app, you have code in place to register their device with your server. It's a best practice to re-register with the server each time the app is opened to prevent any issues when the user gets a new device and restores it from a back-up of their old one.



The user can turn off Push Notifications on a per-app basis in the Settings app. If they turn off Notifications in your app, or if they uninstall your app, Apple provides a Feedback service which you query to find out who to stop sending Notifications to.

Answer 4

Basically, once you quit out of an app, it is no longer running on your iPhone anymore (meaning it's not using any battery power or slowing down anything else you are doing)



...But sometimes it is useful for certain apps to be able to inform you of things even when your not using that particular app, for example an IM application, you might want to quit out of it, but still be able to receive messages. Instead of just keeping the app running in the background and using battery life, and slowing other things down...Apple allows developers to 'push' messages to your iPhone which will let you know when someone sends you an IM and prompts you to re-open the app, if you want to do so.



I hope this makes sense.