When didReceiveLocalNotification is called, I would like to know if it is because a user clicked the notification from outside of my app, or if it is called because my app was the foreground app when the alarm occurred. It is important to know the difference because in one case the user already got an alert with some info and doesn't need it again, in the other case they have not already received that info.
I am currently setting a flag in applicationWillEnterForeground and clearing in applicationDidBecomeActive. If the flag is set when didReceiveLocalNotification is called, I know it is coming from outside of my app and the user already saw the system notification in some form. However, I just noticed this flag will not be set if the user gets the notification, but doesn't click it yet (so it's just in the pull-down notification area), then clicks it from that area while my app is in the foreground. In this case my app is already in the foreground, so the flag is set.
Ideally there would be a property set on UILocationNotification that I can check to get this info.
I suppose I could use the fireDate and say if it is less than 1 or 2 seconds old, and flag is not set, then I am getting the notification real-time, not at a later time.. but I prefer something more robust if possible.
Edit: Right as I was clicking save I noticed the "related" section had this link:
iOS - Need to distinguish UILocalNotification in application:didReceiveLocalNotification:
Sorry for posting a duplicate question without searching more first (I did search, really!). Hopefully maybe this will get a better answer though, since that one doesn't really have a robust answer -- but maybe there isn't one.
Related
I am developing an application in which I want to snooze the received notification automatically for 10 mins, if user didn't take any action (neither dismiss notification, nor opened the app) on the previously displayed notification. This is required in iOS
You can't do that. Have you ever seen an app behave that way? No, because it's impossible (and incoherent).
Think of it this way. If the user does nothing, your app gets no signal that the notification fired. So it cannot "do" anything in response. You cannot respond to something that didn't happen.
Here's another way to look at it. When the notification fires, your app might not even be running. If the user does nothing, your app still won't be running. So how can it "do" anything?
In a comment, you referenced an app that has an "autosnooze" feature. But that app likely isn't snoozing in response to the fact that the user didn't do anything. It is scheduling a repeating notification (or multiple notifications) in advance, so the repetitions are already present when the user does nothing. When the user does respond, the app deletes the extra scheduled notifications. So you see, as I said before, the app responds to something that the user did do, not to something the user didn't do (though I can see why this behavior might give the illusion that it does what you asked to do).
To get the device settings time change notification, i found that we have to use UIApplication.significantTimeChangeNotification notification and func applicationSignificantTimeChange(_ application: UIApplication) delegate method.
But in my case even though if app in background or in killed state, then i have to show local notification to the user saying that device time is changed. Is it possible, Please let me know if we have any solution for this.
From Apple Document on applicationSignificantTimeChange
If your app is currently suspended, this message is queued until your
app returns to the foreground, at which point it is delivered. If
multiple time changes occur, only the most recent one is delivered.
So, it clearly conveys that this will work only when the app is in Foreground. It is not even queued up when the app is not running.
To display any local notifications when the app is not running, it should be scheduled in the past to trigger it in the future. And it is not possible for the app to know about the time change event when it is not running. It looks like you would not be able to achieve what you have asked.
I don't believe it is. iOS cannot deliver notifications to an app that is not running and they don't get queued up anywhere.
One potential workaround for this however could be to take the current UTC value from a trusted, online source and compare it with what the device thinks UTC is and store that offset. Once your app restarts, calculate this offset again and if it's significantly different from the one you stored previously, take the action you'd take in response to the Significant Time Change notification.
The idea behind this app is very simple: download a file. However this app will be for people who are not always within internet access range, so I need it to know that at, say 9:00 AM, to download a file to the hard drive. There will be a button within the app to do it manually as well, but I've already got that working.
As I understand it, this will be difficult if it is even possible. I know that iOS doesn't like multitasking, but I am also aware that it does allow for background timer functions. I am open to any sort of suggestions anyone might have to accomplish this, even if it means writing a separate app. Thanks.
Edit: I see there is the possibility of working with Notifications, or even maybe the Calendar. Ideas in that category as also welcomed.
Edit 2: I also read something about an external server initiating an app, but it gave no description.
Here's the situation regarding background execution and notifications and timers etc. in relation to an app scheduling some activity to happen periodically.
An app cannot execute in the background unless:
It requests extra time from the OS to do so. This is done using beginBackgroundTaskWithExpirationHandler. It is not specified (intentionally) by Apple how long this extra time is, however in practice it is around 10 minutes.
An app has a background mode, the modes are: voip, audio, location, newstand. Even if it has one of these types an app cannot execute without some restrictions. The rest of this discussion assumes the app does not have a background mode.
When an app is suspended it cannot do ANYTHING to rouse itself directly. It cannot previously have scheduled an NSTimer, it cannot make use of something like performSelector:afterDelay. etc.
The ONLY way the app can become active again is if the USER does something to make it active. The user can do this from via of the following:
Launch the app directly from its icon
Launch the app in response to a local notification that was previously scheduled by the app while it was active.
Launch the app in response to a remote notification sent by a server.
A few others: such as URL launching if the app is registered to deal with launching via a url; or if its registered to be capable of dealing with a certain type of content.
If an app is in the foreground when a local/remote notification fires then the app receives it directly.
If the app is not currently in the foreground when a local/remote notification fires then the app DOES NOT receive it. There is no code that is executed when the notification fires!
Only IF the user selects the notification will the app become active and it can execute.
Note that the user can disable notifications, either for the entire device, or just for a specific application, in which case the user will never see them. If the device is turned off when a notification is due to fire then it is lost.
You could use local notifications. They execute code when the user opens the notification that is presented. You can set the local notification to recur at a specified interval (e.g. daily, hourly, weekly, etc). This still requires the user to open the app to get the process started.
UILocalNotification Class Reference
Once the delegate method fires, you only get a few seconds to execute code. Register for a long running background task, and download whatever you need to do. If it can't finish downloading in the 10 minutes you get for the task, then you need to rethink your download strategy.
Apple Multitasking and Backgrounding
We are using this same concept on iOS apps where I work, so this will work if you set it up right.
UPDATE
For those curious how this will work, you just need to implement the UILocalNotification delegate methods. They inherit from the UIApplicationDelegate that should already be in place.
-(void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification {
// start your long running bg task here and update your file
}
** UPDATE 2 **
Martin H's answer is the most correct so far. But this begs the question, if the user never opens the app, what is the point of downloading data they are never going to see? A recurring local notification reminding them to open the app and update may be the best way, but still requires the user to interact with your app if they want it to remain current and up-to-date.
Background applications have a set time limit (I believe 10 minutes, but don't quote me on that, it could be less) to complete whatever they are working on. You will not be able to use background tasks to do what you want.
What you can do is set an NSUserDefault with the date of the last download. On launch check the date saved, if the date is not the current date, and it is after 9:00am, initiate the download programatically.
I am pretty sure this is not possible, at most what you can do is send push notifications to the user, so that they manually update when required.
Have you tried the following?
if ([[[UIDevice currentDevice] systemVersion] floatValue] >=7.0)
[[UIApplication sharedApplication] setMinimumBackgroundFetchInterval:600];
- (void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
completionHandler(UIBackgroundFetchResultNewData);
}
I am wondering if it's possible to do what the titles says. I have an application that has a refill reminder to refill your prescription drug via local notifications. I have seen that some apps (pill reminder apps mostly) push a notification if you have not taken your pill, or have not answered back to that notification, and was wondering if I can do the same if a user doesn't open/interact with the app after a certain period of time.
I have not began implementation but have thought about this thoroughly. What I am thinking of doing is having some sort of flag when the app is opened that removes that local notification and sets a new one once the app has gone in the background/inactive. The local notification would be set to three months from when the app has gone in the background/inactive. The question then becomes, how do I handle canceling all notifications after this notification has been received, regardless of whether the user opens the app at that notification or not?
If the user opens the app on that notification, I can have a check the method application:didReceiveLocalNotification and then handle the case where that local notification has been set and then use [[UIApplication sharedApplication] cancelAllLocalNotifications]
But if the user does not tap or open the app, how can I check and cancel all local notifications?
Sorry if this is a bit long or worded weirdly (sorry not good with words and explaining things). Let me know if you need more info or better explanation. Thanks in advance!
If I understand your question correctly, you want to know how to keep notifications from repeating when the user does not respond to a notification by opening your app.
You might consider configuring your local notification not to repeat. Instead, you might reschedule notification batches each time the application is launched.
Alternatively, if your application has a server-side component, you can use push notifications on iOS 7+ to wake your app, briefly. There is no equivalent to this behavior using UILocalNotification.
The idea behind this app is very simple: download a file. However this app will be for people who are not always within internet access range, so I need it to know that at, say 9:00 AM, to download a file to the hard drive. There will be a button within the app to do it manually as well, but I've already got that working.
As I understand it, this will be difficult if it is even possible. I know that iOS doesn't like multitasking, but I am also aware that it does allow for background timer functions. I am open to any sort of suggestions anyone might have to accomplish this, even if it means writing a separate app. Thanks.
Edit: I see there is the possibility of working with Notifications, or even maybe the Calendar. Ideas in that category as also welcomed.
Edit 2: I also read something about an external server initiating an app, but it gave no description.
Here's the situation regarding background execution and notifications and timers etc. in relation to an app scheduling some activity to happen periodically.
An app cannot execute in the background unless:
It requests extra time from the OS to do so. This is done using beginBackgroundTaskWithExpirationHandler. It is not specified (intentionally) by Apple how long this extra time is, however in practice it is around 10 minutes.
An app has a background mode, the modes are: voip, audio, location, newstand. Even if it has one of these types an app cannot execute without some restrictions. The rest of this discussion assumes the app does not have a background mode.
When an app is suspended it cannot do ANYTHING to rouse itself directly. It cannot previously have scheduled an NSTimer, it cannot make use of something like performSelector:afterDelay. etc.
The ONLY way the app can become active again is if the USER does something to make it active. The user can do this from via of the following:
Launch the app directly from its icon
Launch the app in response to a local notification that was previously scheduled by the app while it was active.
Launch the app in response to a remote notification sent by a server.
A few others: such as URL launching if the app is registered to deal with launching via a url; or if its registered to be capable of dealing with a certain type of content.
If an app is in the foreground when a local/remote notification fires then the app receives it directly.
If the app is not currently in the foreground when a local/remote notification fires then the app DOES NOT receive it. There is no code that is executed when the notification fires!
Only IF the user selects the notification will the app become active and it can execute.
Note that the user can disable notifications, either for the entire device, or just for a specific application, in which case the user will never see them. If the device is turned off when a notification is due to fire then it is lost.
You could use local notifications. They execute code when the user opens the notification that is presented. You can set the local notification to recur at a specified interval (e.g. daily, hourly, weekly, etc). This still requires the user to open the app to get the process started.
UILocalNotification Class Reference
Once the delegate method fires, you only get a few seconds to execute code. Register for a long running background task, and download whatever you need to do. If it can't finish downloading in the 10 minutes you get for the task, then you need to rethink your download strategy.
Apple Multitasking and Backgrounding
We are using this same concept on iOS apps where I work, so this will work if you set it up right.
UPDATE
For those curious how this will work, you just need to implement the UILocalNotification delegate methods. They inherit from the UIApplicationDelegate that should already be in place.
-(void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification {
// start your long running bg task here and update your file
}
** UPDATE 2 **
Martin H's answer is the most correct so far. But this begs the question, if the user never opens the app, what is the point of downloading data they are never going to see? A recurring local notification reminding them to open the app and update may be the best way, but still requires the user to interact with your app if they want it to remain current and up-to-date.
Background applications have a set time limit (I believe 10 minutes, but don't quote me on that, it could be less) to complete whatever they are working on. You will not be able to use background tasks to do what you want.
What you can do is set an NSUserDefault with the date of the last download. On launch check the date saved, if the date is not the current date, and it is after 9:00am, initiate the download programatically.
I am pretty sure this is not possible, at most what you can do is send push notifications to the user, so that they manually update when required.
Have you tried the following?
if ([[[UIDevice currentDevice] systemVersion] floatValue] >=7.0)
[[UIApplication sharedApplication] setMinimumBackgroundFetchInterval:600];
- (void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
completionHandler(UIBackgroundFetchResultNewData);
}