I started off on the Win8 metro app (javascript) development recently. For notifications, it is clear how the WNS notifications will be useful for creating live tiles.
However the use case for local notifications is not clear to me. I have these two questions:
is it correct to assume local notifications make sense only for apps that would run in the background e.g. when other apps are running or when the system is locked?
if the above is not true, then kindly suggest some examples of when local notifications will be useful.
regards
CGere
Local notifications are useful to update your tile on the start screen that persist after your app was closed/suspended. For example you might want to update the tile when your app closes with some context, perhaps an image from the last level of the game they were on or such.
When your app goes to the background it has a short period of time to suspend after which your app will no longer be running and thus unable o update the tile. You can however create a background task to run on an event/timer to do some work (such as update your tile).
Related
I am trying to make a chat app using XMPP protocol. The app is working fine except it doesn't show message notification when the app is in background. In Android I have used a Service for this purpose, however in Windows Phone I couldn't find anything similar to this.
I am trying Background Tasks for this, but as far as I have understood, they're made to run on prespecified trigger and I cannot add any custom trigger to it. In Android I have put my socket connection and parsing message calls in the service itself so that they can run on background too and the socket doesn't get closed even when the app is stopped.
So my question is, is there any similar way to do it in Windows Phone 8.1 (WinRT, not silverlight) or if Background Task is the only option, can you suggest a way to implement the notification functionality. I don't need the exact code, I just need a push to the right direction.
First: You cannot run a network connection in background.
Suggested way is using PushNotifications:
Either directly with a Toast Notification
Or with a PushTrigger to handle a Raw Notification, work out what to do
with it (who was it from, prepare data, etc.) and then create a ShellToast from it. Adds flexibility and improves user experience, but is quite complex.
Known downside: You have to use a server.
Only workarounds: Background-Tasks that checks for new messages about every 30 Minutes.
I have an application where I need to create local notifications via polling without doing push - primarily due to client infrastructure limitations and their security model.
I've read: http://www.objc.io/issue-5/multitasking.html, I've seen David Chan's WWDC presentation - where single push messages kick off download tasks - but what I truly need is background fetch - on a regular basis - like every ten minutes - in iOS 7.
I've seen the VOIP hacks. No. What non-hack way is there to do this without user interaction or push messages? Any examples you can point me to?
Here's what I know:
Background data tasks will work in the debugger but if you can get a console on an IPA, you'll quickly find out they really are prohibited (thereby invalidated many examples).
Background URL tasks require custom delegates - but fetch completion handlers are iffy. This too I found with an IPA and console.
I would love to avoid using the AFNetworking lib - for something quite simple.
Background fetch is not a reliable solution - you are at the mercy of the OS, and it is not very merciful. Abusing iOS background modes is not a reliable solution - Apple is known to reject applications that enable background modes, such as location, VOIP and music playback, without a legitimate reason. Background URL tasks are not something you can rely upon to wake your app; they will wake it, but the app will not be awake enough in the background to enqueue a background URL task.
Your best and most intended method is still background fetch, but be prepared to be disappointed. Your app will not be woken app in the interval you need. Also, the user can kill the app in the app switcher screen, causing your app to never wake up until opened.
No real reliable method other than push. You need to insist with your client for the sake of user experience.
Unfortunately there is no "reliable" way to do that on iOS. With the background fetch API you are not guaranteed to have process run when you would like it run. As you've said, you've already looked at the API so i'm probably telling you something that you already know. A local notification wouldn't solve your issue either as this isn't a way that you can wake your application up and kick off network events. This is behavior that Apple doesn't want as this would negate the whole purpose of their background task coalescing.
You really need to have a push mechanism in place for something like this, so if this is something that is needed, then you may have to stress that to the client.
I have created the application, which track the GPS Location of user at specific time period. This process is run 3 times in background. So, App need to keep alive in background.
To achieve the our requirement, we use the Location manager (GPS) running in the background. So, it will never been killed by OS. Also, we have run the background task thread while App is in background.
This approach working fine on iOS 6 and before and running more than 10 minute in background.
But in iOS 7 Application going to killed after 10 minute.
Please need suggestion for keep the Timer alive in background.
We would appreciate the earliest response. Thank you in advance.
How to keep app running alive in background in IOS 7 without affecting the battery life.
There's no reason for the app to be killed if it has background location tracking functionality in the Info.plist file and doesn't try to abuse the benefits of that permission.
I'm not sure what's your use case for the tracking functionality, but -- together with an assumption that if there's no record from some period, the tracked device didn't change the location -- setting a distance filter would allow to track the location all the time.
That also allows to put a smaller burden on device's battery, because in certain activity types handled by CLLocationManager, the device may put the location service in idle state if it doesn't detect any significant movement.
if you want to keep app active in background and don't want to go to appstore for some reason (for example you are developing something for your company with using enterprise developer program), you should check deferredLocationUpdates(even on devices which doesn't support them, you just get error in your delegate but app will work) and don't call stopLocationUpdates while in background.(if you use this on app for appstore you have to explain why you needed this to apple of course).
I am working on a Win8-UI-App (previously called Metro...) and trying to implement Periodic (Documentation for different methods) Tile Updates (Live Tiles) for the first time.
I found a couple of very good resources on the internet and was able to do it. Unfortunately the question of where I should register for the notifications remained unsolved:
Do I have to register for Notifications every time the app starts (e.g. in the App.xaml.cs OnLaunched() Method)? - Or is there an other, more professional way to do so? (I could imagine to save if I already registered for the service or is there a variable I can access to see whether notifications are registered?)
thank you!
PS: For everyone who is also new to this see this StackOverflow post, this example, the tile template types and the Dev Center for quick starting :)
Periodic updates will continue until they are explicitly stopped or your app is uninstalled. Technically, you only have to do that once. But, the Guidelines and checklist for periodic updates states
Call the StartPeriodicUpdate or StartPeriodicUpdateBatch method each
time your app is launched or brought into focus. This ensures that the
tile content will be updated each time the user launches or switches
to the app.
According to that, App launch and App resume are good candidates for a call to StartPeriodicUpdate.
So I've read that in iOS, all timers will pause when your app is running in the background. I've also read that you can run tasks in the bg using beginBackgroundTaskWithExpirationHandler (like so).
What I am trying to achieve is to call a method once every 3 minutes, and another method a fixed-amount of time before the first one. I have managed to do this within one NSTimer which repeats in a way that lets me do this. It works fine but is obviously disabled (or paused) when the app is in the background - I can only assume because of the reason described above.
Does anyone know if there's a way to run a timer or at least call something after a specific amount of time so I can do this?
Basically if you want to continue running active in the background you have to meet one of the following requirements. From the Apple docs:
Implementing Long-Running Background Tasks
For tasks that require more execution time to implement, you must
request specific permissions to run them in the background without
their being suspended. In iOS, only specific app types are allowed to
run in the background:
Apps that play audible content to the user while in the background, such as a music player app
Apps that keep users informed of their location at all times, such as a navigation app
Apps that support Voice over Internet Protocol (VoIP)
Newsstand apps that need to download and process new content
Apps that receive regular updates from external accessories
Apps that implement these services must declare the services they
support and use system frameworks to implement the relevant aspects of
those services. Declaring the services lets the system know which
services you use, but in some cases it is the system frameworks that
actually prevent your application from being suspended.
http://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/ManagingYourApplicationsFlow/ManagingYourApplicationsFlow.html#//apple_ref/doc/uid/TP40007072-CH4-SW24