I'm trying to develop a little app in order to learn coding for iOS. The app needs to check the battery level every minute and accordingly send an HTTP request. This works when the app is awake.
How can I make it run when the device is put in sleep mode?
The short answer is you can't, or at least shouldn't.
Apple doesn't allow apps to run in the background for extended periods of time with a few exceptions like navigation apps, VoIP apps and a few others (a full list can be found here).
I recommend that you read about UIBackgroundModes and the app lifecycle in the link I attached.
Happy coding!
Related
It seems like older versions of iOS allowed your app to run for 10 minutes in the background. Now it seems like iOS only allows your app to run for a maximum of 3 minutes. I haven't found any documentation mentioning when, or in which versions, this changed, or any estimates provided by Apple for how long your app can run in the background.
I need to be able to run in the background, because my app is connected to an external device via TCP. I already know about the hacks you can do with VOIP and playing silent audio (both will get your app rejected).
Is there anything I can do to get my app to keep running in the background longer than 3 minutes?
We haven’t had the old 10 minute window for years so that is simply no longer applicable. That was reduced to 3 minutes in OS 7, and further reduced to 30 seconds in iOS 13. (There is a new concept of background tasks, for running tasks longer than 30 seconds, but the the OS will run these at its own discretion, e.g. at night, when the user is charging their device, so that’s not really applicable here).
The short answer to your question is that you cannot submit apps to the store that run in the background indefinitely unless it’s one of a very limited list of permitted background modes.
If you can go to the “Signing & Capabilities” tab of your target and add “Background Modes” and you can see the list of alternatives:
So, with the caveat that you cannot do precisely what you asked, here are a few observations:
The “External accessory communication” background mode (see ExternalAccessory) seems promising, but that’s for bluetooth or wired connections only. So unless you can refactor/reengineer how your devices communicates, that is likely not a viable solution.
There’s an interesting question of whether just keeping the app running in the foreground might be helpful (e.g. judicious use of idleTimerDisabled). I know this solves a different problem (and should be used only where essential), but perhaps it’s option for you.
If your external device is Internet-enabled and you want it to inform the app of some event, perhaps you can have it communicate its intent to some web service that then triggers an APNS push notification that your device can receive.
Bottom line, you can’t do what you ask, but if you edit your question with more details about the nature of the device and what your iOS app wants to do with that device, we might be able to provide better counsel. But in answer to the general question “can I just keep app running perpetually in the background”, the answer is “no.”
I searched informations about possibilities when running an iOS app on background, but I didn't found same on different sites.
My application has to read the battery level (with step of 1%) and the time, but I don't know if I can read that when running on background.
Please if someone is sure about it or know a site to read these infos, it will be very nice.
EDIT : I've one more question, can I just open my app (to perform more actions) when the notification center return a battery state under 5% for example ?
No, you can't.
It's not possible to let your app running on background, it's iOS system's limitations.
In iOS 7.0 and later, you have opportunity to do some pre-fetch stuff even your app is not running, through the method like application:performFetchWithCompletionHandler:, but you should tell the device by posting remote notification from your server.
I'm currently developing an app using enterprise account for internal purposes only.
I heard something about daemon for jailbroken devices in order to make my app just like an android service.
Is there anything I can do when not jailbroken?
Maybe 3rd party framework or piece of codes? Maybe private framework?
Something like this maybe: Make the application restart by itself on a jailbroken device
But for non-jailbroken.
P.S. - The app of course is not for app store and could not be on app store.
I agree with Tander. But we have achieved almost similar effect using combination of SLC (Significant Location Change), Background fetch and Silent push notifications. Whole point is that app periodically trigger call to API to let know it is alive.
If this fails, we sent normal Push Notification. I was looking into this for fair amount of time and didn't come up with nothing better. But note that you get very limited process time to execute code using this options.
Unless the device is jail broken the short answer is no.
I'm newbie iOS. I have been develop Phonegap for Android and iOS. My App is update data from server every 1hour. In Android, i use service to do that. My app in Android working very good. Now, i want to develop version for iOS, and i have problem when update data from server every 1hour. I was research but not find anyway for my app.I don't know what's solution to replace for service in Android. Can you help me, what's solution. This have been kill me. Thank you so much.
Short answer is NO as Apple has restriction on background task running especially cases like yours.
But if you are downloading small amount of content, you do have some other options. From IOS 4.0 or above, you can declare your app to run in background when you fall under the following categories:
Audio
Location updates
Voice over IP
Newsstand downloads
External accessory communication
Bluetooth networking
Bluetooth data sharing
Background fetch (IOS 7)
Remote notifications (IOS 7)
In order to do so, you need to flag your app in the info.plist for Required Background Modes option. Apple will review your app specific in this area once you declared the option.
For your case to download the data, the possible option is to use the new feature in IOS 7 that's the background fetch or remote notification above. The suggestion from DOM was not asking you to download the content through push notification. But instead to use push notification to wake up your application and start downloading new content.
If you don't want to use push notification, the only way to go is register for background fetch. However, no matter which option you want to use, each download will only last for 30 seconds. And after that, your app will put into suspension mode again.
you can have a look on the link here:
Declaring Your App’s Supported Background Tasks
I think your best bet would be to use the push services instead of having your app go get data. Making your app do it is unreliable with phonegap apps because you cant create a service interface and you can not guarantee that your app will be running. With push service though, if your app isn't running, it will be woken up in a manner of speaking.
Take a look at this great how-to article that also discusses what push provides you.
This is a strange one, I have a need to create an iOS app that runs in the background on an iOS device, but can not be visible on the Home screen of the device. The app may need to show up in Settings to configure a few options, but it mostly needs to run behind the scenes.
I do not need to publish this app on the app store, it is strictly an enterprise app for my company.
Does anyone know how this kind of behavior might be achieved? Configuration profiles? API's? etc?
Edit: Jailbreaking the device is not really an option for us. We have to keep the devices as they are.
Backgrounding
There are several methods to get permanent background execution:
a) Silent audio which is mentioned by JRG-Developer
b) Usage of beginBackgroundTaskWithExpirationHandler + turning location manager on/off (it will reset remaining time to 600 seconds)
Making app invisible
You can use SBAppTags in Info.plist (take a look at this: How to remove app icon programatically from jail broken iPhone app?)
It will make your icon not visible on Home screen.
I've no idea how you can tackle the not be visible on the home screen criteria, but there are certain services that are allowed to be run in the background continuously, notably:
Background Audio (even silent audio)
While this is indeed very hacky, short of jailbreaking the devices, this may be your best bet.
While it's unlikely / very difficult to get past the review process, in the event for some reason you do need to (attempt) to publish this app to the App Store, some apps are even available on the App Store which take advantage of this hack, such as PasteBot.
You should definitely read their write-up here about getting their app's Cut-and-Paste functionality to work while in the background:
http://tapbots.com/blog/pastebot/pastebot-music-in-background
Another out-of-the-box idea, why not use Android devices instead, which do support multitasking?
Two methods:
Jailbreak. A jailbroken iPhone is essentially a Mac and you can use all Mac UNIX programming tricks - spawn a daemon (you can even ask launchd to do that), or something. You can set up enteprise-wise Cydia source. Refer to saurik's website for a walkthrough and set up an experimental server using Ubuntu (which used apt too)
A non-jailbreak way may be possible, but it will depend on what your app is doing. You can try use enterprise-wise push notifications.
Given that this is impossible to do on non jailbroken phones, I'd suggest the following:
develop a directory app, or a phone list app, something that is specific to your company.
have it connect to a web service once a day to register the device ID (so you know the user has not deleted the app)
tell users they need to keep the app open at all times (and if a user's device does not register one day, send them an email asking them to launch the app).
Now you can send back whatever you want with the app. If they kill it, you'll know the next day when you have a script look at the logs.
If you think this is a terrible idea, it is, but its the best you are going to get on iOS right now.
EDIT: you could send a notification every day - say in the AM - to make sure the user opened the app if it wasn't running.
From my experince, this kind of behaviour cannot be achieved on iOS. When an app enters into background, it is active only for a small particular amount of time. After that, it goes into hybernate state. It stops working. So the behaviour you said can not be achieved without abusing iOS workflow. Thats why some call iOS's multitasking as not true multitasking. Only jailbreaking might help your case. That was for one case. The second one where the app cannot be seen on home screen is again, impossible. It has to be on springboard to run.