I need to know if i can get the location on background mode. Could i get the battery level to work with it.
Or the apple store will reject the app because the limits of the background modes I can work with.
Click on projects.
Click on Target.
Click on Capabilities.
Click on Background Modes.
Click on Location updates.
your location delegates are called even when your app is in background mode.
Apple docs have good information about saving battery. Which location services you need to use according to your apps need.
https://developer.apple.com/library/ios/documentation/userexperience/conceptual/LocationAwarenessPG/CoreLocation/CoreLocation.html#//apple_ref/doc/uid/TP40009497-CH2-SW1
To get battery level
https://developer.apple.com/library/ios/documentation/uikit/reference/UIDevice_Class/Reference/UIDevice.html#//apple_ref/occ/instp/UIDevice/batteryLevel
You can get the location in background mode.
And you can get battery level in background when location update is received.
But please take a look into Apple Review Guidelines.
2.16 Multitasking Apps may only use background services for their intended purposes: VoIP, audio playback, location, task completion,
local notifications, etc.
Related
Do background mode functions like Background fetch and Location update work if the app is terminated? Or it only works if the app enters background?
Thanks
Yes, it works (most of the time), if you set up everything correctly and have the permissions. Your app need's to be launched at least 1 time, so it can subscribe to the updates.
For background fetch, set UIApplication.shared.setMinimumBackgroundFetchInterval(3600) at the didFinishLaunching method, implement the performFetchWithCompletionHandler method, and enable the Background Fetch in the Background Modes.
Pay attention to do it as quickly as possible, and call the completionHandler as soon as possible.
Read more on Updating Your App with Background App Refresh here
For notification updates, you must also set the allowsBackgroundLocationUpdates property of your CLLocationManager object to true, and enable the Location updates in the Background Modes.
Read more on Handling Location Events in the Background here
Background fetch works like, it allows the app to download the contents when it is background. If the app is terminated and gets some trigger to download content, it will actually wake up by doing silent-launch of the app in the background and download the contents. Please see the Apple description on this below.
Each of the preceding modes lets the system know that your app should
be woken up or launched at appropriate times to respond to relevant
events. For example, an app that begins playing music and then moves
to the background still needs execution time to fill the audio output
buffers. Enabling the Audio mode tells the system frameworks that they
should continue to make the necessary callbacks to the app at
appropriate intervals. If the app does not select this mode, any audio
being played or recorded by the app stops when the app moves to the
background.
Here, preceding modes refer to Background fetch, Audio and AirPlay, Location updates and other Background modes of the app.
Please refer Apple document on Background Execution. See Declaring Your App’s Supported Background Tasks for more info on different background modes.
Location update works differently. There are multiple Apple services available to fetch location.
Significant Location service: It works in all modes. Foreground, Background and even in terminated mode.
Standard Location service: It works only in FG and BG mode. It does not work when the app is in terminated mode.
On more details on Location in BG, please refer Handling Location Events in the Background document.
Hope it helps.
Background fetch and Location update work if the app is terminated? Or it only works if the app enters background?
It depends on which type of location service you have used in the project. Refer below analysis of all types of location services.
Standard location service: If you implemented standard location service then it will work only for background and foreground
state.
Significant location updates: If you implemented significant location updates then it will work for background, foreground and
terminate state as well.
Region Monitoring: If you implemented significant location updates then it will work for background, foreground and
terminate state as well.
Visits Location Service: If you implemented Visits Location Service then it will work for background, foreground and
terminate state as well.
Please refer below references.
Apple official doc
Raywenderlich article
I have a requirement where i need to track the iphone device state like if device is locked or unlocked. I was able to track these events when the app is running in foreground or background. But i also need to track the same when the app is suspended. Something like tracking the user location in background when the app is suspended. But i don't need to track the user location but only the device state.
Please suggest me some steps to solve this issue in objective-c.Thanks in advance.
You can not perform any operations once your app is in suspended state and you can not prevent your app from getting suspended unless you are using one of the background capability mode mentioned in this apple doc
So what you are looking for is not possible if you are not using either of background modes allowed by apple.
EDIT
Even if you go on and enable one of background mode like background audio, your app is likely to be rejected during review process as reviewer will see you do not have a valid reason to use that particular background mode.
I am using Skobbler sdk in my application for navigation. I need to continuously send data of navigation to other device. But the navigation in background works for only 15 minutes after that it stops navigating in background. I have also tried enabling the following key value pairs in plist :
Required Background modes-
1. App registers for location updates
2. App downloads content from the network
Please suggest some help.
Please test this in a real situation, like actually driving while using the app with navigation type being SKNavigationTypeReal.
Background apps are suspended after some time and only activated when they actually receive GPS location updates. Your app will never resume if the device is not actually moving.
This is an optimization done by Apple to improve battery life.
Some more info about background modes:
https://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html
The next release will include an API to disable this behavior.
I am creating an alarm clock app that requires some user action within the app in order to turn the alarm off. Below is a picture of what another app, Sleep Cycle, does when you turn an alarm on and press the home screen (i.e. background the app).
Here is an image link (I can't post an image yet, no rep despite my many attempts to answer people's questions today) for the effect I want to re-create.
Those that have used iPhone's Personal Hotspot and connected a device will notice that it is the same effect, where a notification appears at the top of the UI - pushing everything down by around 20-40 points. This is highly desirable to an alarm clock app as it encourages the user to keep the app in the foreground so that the app can easily be entered when waking up (instead of relying on the 30 second sound window allowed by local notifications)
Does anyone have any ideas on how to implement this functionality. I assume that it must go somewhere in the:
- (void)applicationDidEnterBackground:(UIApplication *)application
tag within the AppDelegate, but I'm not sure what exactly I need to be reading up on. So if anyone has a link to some relevant Developer Docs that would also be extremely helpful.
Many thanks for your help,
Ryan
There are a handful of built in 'background modes' that change the status bar's appearance depending on what functionality an app provides whilst it's in the background. The one you've identified (a red status bar) is triggered when an app records audio whilst in the background. I presume Sleep Cycle must be acting as though it records audio just for this purpose. Other background modes include VoIP (which I think uses a blue status bar). Check out Apple's documentation on supporting these various background modes
In your case, you'd want to add audio to the UIBackgroundModes property in your Info.plist file.
But note that it wouldn't be unreasonable for Apple to reject an app during review if it pretends to perform one of these background tasks but doesn't. For example, there have been apps in the past that tried playing a silent audio clip continuously in order to stay awake in the background - needless to say Apple got wise to this and the app in question had to change its behaviour.
The question "Background GPS in iOS. Is this possible?" does not answer this question.
I have a mapping app that uses MKMapView and its built-in location services when the app is active. When the app is in the background, I would still like location updates to be delivered and processed. For that, I'm using CLLocationManager.
I have location updates enabled in the plist file and call startUpdateLocation in the AppDelegate code which also acts as the delegate for CLLocationManager. This is everything mentioned in "Background GPS in iOS. Is this possible?",
When the app is active, everything works okay, getting updates no problem.
But when put in background mode, the little arrow indicating location services are being used comes on, but then disappears after about ten seconds. In this brief time period, the app seems to be able to receive location updates, but when the arrow is gone, no more updates.
Am I doing something wrong? Does MKMapView override what CLLocationManager wants to do?
Make sure "Background App Refresh" is enabled in your settings. You can check this programmatically by using backgroundRefreshStatus of UIApplication.
To receive location updates in the background, do the following:
Make sure to have a started CLLocationManager
Make sure to have the following value in your info.plist:
"Required background modes" = "App registers for location updates"
Avoid doing a lot of complicated things in your locationManager:didUpdateToLocation. In particular, avoid UI operations. Your execution time is limited by iOS, and not all APIs are available.
Everything is well documented, see "Getting Location Events in the Background" in the documentation.