Is it possible to wake up an app every x minutes, so that the application can do something in the background? So the app stays in the background.
No, such behavior is not supported by the iOS SDK.
This doesn't wake an app up every x minutes, but will launch an app into the background:
An app can be woken by a significant location change, if the app has indicated that it wants to monitor such events.
See: CLLocationManager Docs
Look for a method called startMonitoringSignificantLocationChanges. If a significant location change occurs while your app is not in the foreground or isn't running at all, your application will be launched in the background, allowing the app to perform background-only operations (e.g. no view code will run).
You cannot wake your app programmatically. You could incorporate push notifications; however, the user would have to opt to open the notification.
No, you can use internal (like reminder) or external (push) notification to to open an app. however, the user would have to opt to open the notification.
Related
I am developing an app which uses CLLocationManager to track user's current location.
As soon as I launch app, it works well till the end of the day, I used to get the user's location till evening 5'o clock.
I want my app to start automatically on the next day morning, without launching the app but my app is running in the background.
I just want to work like alarm manager in android. Any suggestions?
I want CLLocationManager to startUpdatingLocation even when the device is rebooted without launching the app [while switching off the device, the app is running in background]
How to implement this?
iOS will relaunch apps that sign up for location changes! This works under ios6 already! BUT to the background only. So that the location can be tracked
see e.g. the 'Moves' app that will track your location
the idea is that you're app wakes to the background mode.
see:
Will iOS wake up the terminated app if it's registered with location for UIBackgroundModes?
pay attention to:
App won't relaunch when monitoring CLLocationManager significant location changes - iPhone
compare with:
http://developer.apple.com/library/ios/#DOCUMENTATION/iPhone/Conceptual/iPhoneOSProgrammingGuide/ManagingYourApplicationsFlow/ManagingYourApplicationsFlow.html
You simply can't do what you want with iOS 6 or lower (app can't launch itself on those iOS versions), workaround would be to alarm user to launch your app with local notifications. But iOS 7 comes with some new features, and allows certain apps to wake at the background to complete tasks.
You can not make startUpdatingLocation(didUpdateLocations) automatically run after reboot. You have to
1. use startMonitoringForRegion ;
2. or use a remote notification to invoke startUpdatingLocation.
I'am developing an application that keep a WebService informed for device location each 5minute (for exemple) :
So when the application leave the foreground execution and enter background I have to lunch a timer who
1 - Update the device location
2 - Send the location to a web service
How can I perform this action ? Or do you know any code exemple that I can follow to achieve this design ?
Thank you for your help !
Doesn't look like anyone gave you a solid answer, so allow me.
There is no iOS approved way of running a 5 minute (or any minute) timer in the background (unless your app is VOIP or music). What you CAN do is register your app as requiring location services in the background (edit the info.plist and add a key Required Background Modes and then add a value App registers for location updates. What this means is your locationManager:didUpdateToLocation:fromLocation: method and corresponding region monitoring/SLC methods will fire on location change, but Timers will not work at all.
The reason why is that timers require a run loop (a thread executing code) to be running and must piggy-back on that thread, but when the app is in the background even when executing code from the LocationManager, the run loop that executes the code almost always finishes before your timer would go off.
Hope this helps!
you cannot do this (on iOS).
(unless your app requests permissions that are meant for Navigation apps)
Hello #Aladdin Gallas,
I have developed a simple application that supports background location updates for iOS and Android in Xamarin.
The app pushes a new location every 2 seconds (you can change it to 5 minutes if you want to).
There is a feature I haven't been able to add; it is to keep the service up when the user closes the app (for iPhone). Other than that, as long as the app is open, even if the phone is locked, the service keeps running.
You can take a look at the application as a reference if it helps.
GitHub Repo
I am writing an alarm clock app for iphone, and I want it to turn on the phone(from standby mode) approx 1hr before the alarm is supposed to go off.
Then I want the app to be active, so I can stream content live without the user having to put the phone in an active-mode.
Any way for an app to switch out of standby?
Without using private api an application can only present alertview (via local or push notification).
And only when user taps "view" button this application can be activated. You can see that in the link you provided - (second to last screenshot)
True, you can always add sound to this notifications - so alarm app can work (and there are many out there) but it can't send itself in the foreground.
Nope that cant be done, once the app went to the background state you lose control on it, and cannot bring it back
There might be a way using notifications. Check this SO question for more info:
Alarm Even Application Closed in iPhone
I have an iphone app that has a 30second process that does some network IO. Basically, while the app is in the background, i want this process to run every hour (actually once a day, but if it fails i want it to re-run in an hours time).
With the background features of ios 4, is this possible? If so, how? What are the limitations that i'll come up against?
Thanks so much!
Take a look at Apple's documentation about running code in the background.
http://developer.apple.com/library/ios/#documentation/iphone/conceptual/iphoneosprogrammingguide/BackgroundExecution/BackgroundExecution.html
There are few different ways of approaching backgrounded tasks. The only apps that can have fully backgrounded processes are "audio", "voip" and "location" apps, and this needs to be declared in the Info.plist.
If your app is not of this type, you'll probably find it difficult to do what you want easily. There are methods which allow you to keep your app alive in the background for a finite period of time (also at that link), but eventually your app will be shut down.
Local Notifications will only prompt the user to open the app - do you really want to have an alert pop-up on the phone every 30 seconds?
I was making some kind of similar research, have a look at this SO answer in case you didn't manage to find it before. Applications like DataMan or Data Usage must have some sort of periodic code execution in the background, so I'm not 100% convinced that what you're asking for is impossible..
I believe that Using Local notifications will help....
check following....
http://developer.apple.com/library/ios/#documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/IPhoneOSClientImp/IPhoneOSClientImp.html#//apple_ref/doc/uid/TP40008194-CH103-SW1
An application can create and schedule a local notification, and the operating system then delivers it at the schedule date and time. If it delivers it when the application is not active in the foreground, it displays an alert, badges the application icon, or plays a sound—whatever is specified in the UILocalNotification object. If the application is running in the foreground, there is no alert, badging, or sound; instead, the application:didReceiveLocalNotification: method is called if the delegate implements it.
The delegate can inspect the properties of the notification and, if the notification includes custom data in its userInfo dictionary, it can access that data and process it accordingly. On the other hand, if the local notification only badges the application icon, and the user in response launches the application, the application:didFinishLaunchingWithOptions: method is invoked, but no UILocalNotification object is included in the options dictionary.
I have noticed that some apps e.g. Skype run in the background.
I would like to have my app run in the background also, waking up every 1 seconds to update some data and then going to sleep again.
How can I do this?
I gather that NSTimer's do not work in the background.
You can't. Voice-over-IP apps get a special exception for this, basically the system manages a network socket for them and wakes them up if there's data. There's no way to do the same with a timer.
By the way, waking your app every second, your battery wouldn't last half a day.
See Executing Code in the Background
You would need to use push notifications to push information to the app (like the Facebook or Skype app). See this documentation from Apple on how to use push notifications.
Not every second though, that would drain the battery. Other than that, there isn't really a way unless you are running a VoIP app.