I want my iOS app to know when a specific date and time arrives without any failure. Now this time can be in days/weeks/months and my application can be in backgorund Or in terminated state.
So there are following options:
a. Local notification -- but it doesn't notify when my app is in background.
b. Silent Push notification -- it will work but it requires us to built server for same.
Is there any other option with which we can achieve same?
There is no way you can achieve this,
Your options are :
1) By using local notification like schedule notification on particular time and store that time and related activity in userdefaults. whenever app state changes to background to foreground in appdelegates - (void)applicationDidBecomeActive:(UIApplication *)application method write a code to handle desired functionality.
2) Silent push notification, which works only when your app is in background/minimized state. Once your app is Killed(swipe up from multitasking), even silent push notification cannot wake up your app.
3) To overcome the limitations of silent push notifications, Apple introduced Pushkit Notifications in iOS8, for voip apps like whatsapp, Skype, etc, in which push kit notification once received, wakes up your app even it is terminated or not running in background. Again you cannot use Pushkit unless you are actually using voip.
No. Sounds like you have to use push notifications.
This is the only thing that would work if your app is terminated.
Related
Right now I have a framework that receives a silent notification, get the data from it (custom data) and translate it into a local notification to show the alert to the user (this is donde in didReceiveRemoteNotification:fetchCompletionHandler method). I have implemented this framework on an app and everything seems to be working correctly, silent notifications are being process when the app is in background and foreground. However, when the app is killed by the user or it is not running, I cannot receive notifications because of this:
Use this method to process incoming remote notifications for your app.
Unlike the application:didReceiveRemoteNotification: method, which is
called only when your app is running in the foreground, the system
calls this method when your app is running in the foreground or
background. In addition, if you enabled the remote notifications
background mode, the system launches your app (or wakes it from the
suspended state) and puts it in the background state when a remote
notification arrives. However, the system does not automatically
launch your app if the user has force-quit it. In that situation, the
user must relaunch your app or restart the device before the system
attempts to launch your app automatically again.
The reason I use this method for showing notifications is because the payload I sent to APNS has custom data with key-values that indicate how the notification must behave.
I've been doing some research and I found that Pushkit for VoIP can do the job. However, many post suggest that this can cause app rejection.
So my question is, how can I achieve receiving remote notifications even if my app was killed and considering that data in the payload has custom information to build the notification?
Silent push notifications are unreliable: they might get delayed, delivered in groups or even not delivered at all.
If you need to modify the content of the notification before presenting a banner for the user, you should use a Notification Service App Extension. You can also share some information between your app and this extension - using app groups or the keychain - if it needs something from your app to process the notification data.
I am trying to implement silent push notification in my application where I need to update some data in the server when silent notification comes. I am using Pushkit and it uses VoIP certificate for silent push notification but the app has been rejectd by Apple saying that "I can't use VoIP" certificate. It seems that apple has rejected it as I don't have any VoIP call functionality in my app. In that case how can I implement silent push notification so that my app gets activated even if it is not runnning(not even in the background) and I can update the server?
From my experience, iOS respects user's choice, so in case the user has killed the app, it will remain killed - no silent push notification will wake this app. VoIP is an exception to that, but as you wrote, it should be used only in VoIP apps. This makes sense, consider it a platform limitation: thanks to that user have some control over what is actually running on the phone, the device consumes less battery and lastly, foreground/system Apps has the most CPU time to utilize.
There are few techniques to work with data in the background:
Content-available push notification: will wake up the application in case it is suspended, or startup it in case it has been killed by the system/crashed. Note, that this only opens a 30-second window and amount of notifications is throttled by APNS.
Background fetch capability will act in a similar manner.
Background task to finish existing task - but this is only used when app is moved to the background.
If you need App to send updates to the server, I believe above should be sufficient (unless your app is spying on a user, it should have all relevant data available once the user finishes interaction with the App).
If you need a server to send data to the App, use silent push notification (or background fetch for periodic pulling), or in case this data is critical to the user, you can present him a remote notification - if the user considers that an important update, he will open the app.
We need to calculate some numbers and display the calculations in local notification on receiving a silent push message from the server.
This works when the app is active/open in background.
This does not work if the app is killed/not in background.
So is there anyway to perform tasks when app is closed and the silent push arrives?
FYI I have enabled background fetch.
Apple's Documentation states:
Note: The ability of APNs to deliver remote notifications to a nonrunning
app requires the app to have been launched at least once.
On an iOS device, if a user force-quits your app using the app
multitasking UI, the app does not receive remote notifications until
the user relaunches it.
The second sentence pertains directly to your question; likely not the answer you hoped for...
↳ Configuring Remote Notification Support
When I receive a remote notification I updated a counter that I save to UserDefaults and I also show a local notification. Everything works as expected when the app is in the foreground, background, and suspended states Ref. When the app is in the Not Running state my counter is not updated nor is my local notification shown.
It is my understanding that I should be able to receive and process Remote Notifications while the app is completely off. A few articles online claim that when a Remote Notification arrives while in the Not Running state that the application:didFinishLaunchingWithOptions: should be called followed by application: didReceiveRemoteNotification:fetchCompletionHandler: but in my case it is not.
Is it possible to receive remote notifications while in Not Running state?
If your app is a VoIP app and you are using VoIP pushes through PushKit then a push notification will launch your app from the terminated state in order to deliver the notification. If you are using standard push notifications then your app will not receive the notification if it is terminated. You can include an alert text with a 'silent' notification that will be displayed to the user in the event that your app is terminated in order to prompt them to launch your app.
First of all, it sounds like you have a silent notification set up. Once you add alert data to your push notification (information like the title, body etc.. you can find more on that here), it'll start to display on the lock screen.
Second, it's not possible for your application to launch from a push notification, silent or otherwise, if it's in the Not Running state. The documentation on this is actually incorrect, as it states that the application will only not be launched if the user has quit the app. However, this actually also applies for any circumstance under the not-running state, for example if your app has never been launched since installation/rebooting, or if it was quit due to memory (a fairly common occurrence - iOS purges apps which haven't been run recently as required).
did you check this mark when app is background?
I am building an app that needs to speak data while the app is in the background (or screen is off). The speaking part is done via AVSpeechSynthesizer.
My Android app launches a service that listens for the data and whenever it needs to say something, I say it and its done. Now iOS doesn't allow these kind background tasks from what I read. The closet thing is called 'Executing Finite-Length Tasks' which looks like has a time limit of 10 mins max. So this will not work for me. Instead it looks like I need to use Push Notifications.
Looking at the documentation for Push Notifications, if I understand it correctly, if my app is in the Foreground, then my app receives the Push Notification instantly. While if my app is in the Background, a notification is set (notification center), and once the user hits the notification, my app launches with the payload.
The question here is, is there anyway to make a push notification wake my app immediately so I can speak some info?
Or what are some of the other alternative approaches that should be used in this case?
My other idea would be to implement some sort of mp3 stream per user, that would stream audio which I could play in the background. But this seems excessive for what I am trying to accomplish?
I'm not sure if you'll be able to invoke speech synthesis from the background, but you can have you app notified when the push arrives. The trick is to implement the
- (void) application: (RMApp *) application didReceiveRemoteNotification: (NSDictionary *) userInfo fetchCompletionHandler: (void (^)(UIBackgroundFetchResult result)) completionHandler
UIApplicationDelegate method (note the completionHandler parameter).
You must also set the Remote Notifications Background Mode capability.
And you must set content-available in your push notification payload.
A decent writeup on these steps found here:
http://samwize.com/2015/08/07/how-to-handle-remote-notification-with-background-mode-enabled/