I'm currently working on an iOS app using objective-C that send every minute gps coordinates to my API.
I've used AFNetworking & CoreLocation, I also wanted my App to run all day long, but only send coordinates if time is between 8am - 6pm.
Everything's working fine on iOS simulator targetting iOS9 my app is sending his location every 1 minute to my API, even if i press home or lock the phone.
PhoneCall, loss of network or GPS have been handled in order to keep my task running.
But when I tested it on some device (iPhone 4S on iOS9) Location stop updating after an average time of 1hour to 1hour and a half.
Is iOS shutting down my app in background after a given time?
If so, is there a way to keep my app doing her job in background for at least 10 hour, without having to prompt the device user?
Implementing long running background task are "allowed" by apple if it concern:
"The app keeps users informed of their location, even while it is running in the background."
Does that mean background task will block my http request after a while?
For long term deployment, I wish my app to be upload on the App Store, but I've read many post about app GPS tracking app which have been rejected.
Here's the minimal list of requirement my app should have:
Send GPS coordinates to my API every minute
Working in background for a minimum time of 10 hours without shutting down or prompting user to reload the view
Could those requirement be accepted to get my app upload on AppStore?
Or will I have to use local/remote notification and prompt the user to reload my app in order to keep it running for such a long time?
The documentation says.
The significant-change location service is highly recommended for apps that do not need high-precision location data. With this service, location updates are generated only when the user’s location changes significantly; thus, it is ideal for social apps or apps that provide the user with noncritical, location-relevant information. If the app is suspended when an update occurs, the system wakes it up in the background to handle the update. If the app starts this service and is then terminated, the system relaunches the app automatically when a new location becomes available. This service is available in iOS 4 and later, and it is available only on devices that contain a cellular radio.
I think this will be apt for your scenario.
Related
First of all it's important to note that I'm developing an Enterprise App, so there is no need for App Store guidelines \ approvals considerations.
My goal is the following:
1) An iPhone app which the user should open only one time only. During this one time he will go through some sign up process.
2) Once step (1) has finished (either by app suspension or app close), the app should "wake up" every hour (more or less) and send the server some data regarding the user from the background (all is done with the user agreement of course).
Optional Solutions I tried:
I read very thoroughly Apple guidelines for running in background in https://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html
I decided to go with 2 UIBackgroundModes:
location
fetch
1) For location I use:
startMonitoringSignificantLocationChanges();
manager.requestAlwaysAuthorization()
In order to make sure my app will run after "app close" or even "device reboot" I had to use both options. See Apple guidelines:
https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/LocationAwarenessPG/CoreLocation/CoreLocation.html#//apple_ref/doc/uid/TP40009497-CH2-SW1
If you leave the significant-change location service running and your
iOS app is subsequently suspended or terminated, the service
automatically wakes up your app when new location data arrives.
2) For background fetch I use
performFetchWithCompletionHandler()
and
UIApplication.sharedApplication().setMinimumBackgroundFetchInterval(UIApplicationBackgroundFetchIntervalMinimum);
For some reason the app doesn't run in background after 24 hours. Meaning the app never "wakes up" again even though according to Apple guidelines whenever significant location update occurs - it suppose to wake up.
What can I do in order to guarantee as much as possible that my app will run regularly in the background?
In your project properties you have to allow background mode for your application to Update location and for background fetch.
Fetch in background is not so easy as it seems.
iOS will define by itself how often it will fetch data in background modeeven you set option for each 15 minutes :(
As my practice shows time interval for fetching new data is less if user open application from time to time so iOS makes some calculations about normal app use. As a result app calls background fetch data according to app ussage.
But you can make one trick:
you can call fetch procedure from you location procedure. For data exchange it was usefull in my projects :)
The solution worked with Silent PN.
My goal as noted in the bounty was: ".. to have an iOS app that runs regularly in the background for 30+ days when not opened at all. Should also run after the app closes."
I found that when sending PN with "content-available" : 1 did the trick for me.
I set up a server which sends every 15 min a "silent PN" to all registered devices. I was able to confirm from the same server that those clients receive the PN and act on it.
Thanks #andlin for the advice.
Many questions concerning iOS Location tracking have been asked on here, but recently Apple has updated much of their functionality and so many of the answers are obsolete, my question is specifically targeting iOS 8 and 9.
I am interested in creating a location tracking application which will accurately track the user even when the app is closed. To do this, apple states:
If you leave the significant-change location service running and your
iOS app is subsequently suspended or terminated, the service
automatically wakes up your app when new location data arrives. At
wake-up time, the app is put into the background and you are given a
small amount of time (around 10 seconds) to manually restart location
services and process the location data.
So my understanding is, if you have all of the necesarry permission and plist keys present, the OS will wake up your app and allow you to do something for 10 seconds, or if it needs more time it can:
If an iOS app needs more time to process the location data, it can
request more background execution time using the
beginBackgroundTaskWithName:expirationHandler: method of the
UIApplication class.
Now, this says that if my app needs more time to process the location data, it may start a background task (with an expirationHandler) to handle that. When reading about background tasks, I read that background tasks can run for a maximum of 10 minutes
So my overall question is, when my app gets woken up when a significant location change has occurred, is it possible to start the standard location service and have it run in the background indefinitely? Is it possible to start another background task before the first one expires?
EDIT:
From the Apple Documentation it says:
because it wakes the system and your app at least every 15 minutes,
even if no location changes have occurred, and it runs continuously
until you stop it
So my idea is, if the user starts their phone from nothing and never opens the app, after at most 15 minutes (even if they are standing still), the OS will fire my app, in which case I could start a background process that I can start the GPS tracking in, and thus getting accurate GPS location. Would this logic work with the OS?
The main problem is that significant location changes cannot be used for
"accurately track" the user.
Significant means 1000m, since it is cell tower based, and not GPS based.
So your app is woke up when the user moves into the next GSM cell.
This is not acurate enough for acurate tracking.
finally this means you cannot acuratley track when the app is closed, this works only in running app or background running up.
"When reading about background tasks, I read that background tasks can
run for a maximum of 10 minutes"
No, thats not true. My app runs in background and records GPS locations until the battery is drained (8h+). (It does not use the significant location mode)
I am creating an app that's using a CLLocationManager to track my position and update it to a database with a Google Map. The sole purpose for this app is to stay in the background and continue to update your location as long as you've logged in and set an Available key to true.
The app works fine in the foreground and it updates my location every minute, but when it's in the background it stops after 15 minutes as the app suspends (I suspect). I've implemented the startMonitoringSignificantLocationChanges() method, but if I stay in one place for too long without opening the app manually after 15 minutes, the updates stops and my map only plots your location for so long without you updating and resetting the lastLogged timestamp.
Is there any way I can force-activate the app to a background state without actually opening the app itself? As the plan is for many people to start using this app, opening the app every 15 minutes is going to be a massive bother and I would love for some way to do this automatically.
Thanks for any help!
PushKit allow you to send messages directly to the people who have installed your app, even when the app is closed on a device or in background.
Its a new framework in iOS 8, is the new push notification mechanism which silently launch your app into the background without the need of user interact with the app.
Here is link in Apple:-
https://developer.apple.com/library/ios/documentation/NetworkingInternet/Reference/PushKit_Framework/
I am creating a private distribution app and I am wondering if it is possible, using any methods or private API's, to open my app when a bluetooth connection has been made.
What I have discovered so far is that with iOS 7 and the ability to use iBeacons you can enter into bluetooth proximity and you can have your app send a notification to allow the user to then open the app.
What I am hoping to do then is have the app running in the background and listen for an iBeacon connection and, if one has been made, actually launch the app without the users control instead of just sending a notification.
I realize this would never be allowed publically, however is there anything private I can look at to achieve this without jailbreaking? I know to launch some apps you can do [[UIApplication sharedApplication] openURL:[NSURL URLWithString:url]]; however I want my app to listen for an iBeacon and then open itself up.
Is there any way or work around to achieve this?
Moving app from background to foreground without user interaction is pain in the ass. Sorry, don't have a solution, just want to share some information:
I asked the same question here and posted a bounty on it and got no good response:
Show some UI from background in audio player or VOIP app on iOS
At some moment I found a solution with the help of another person. It was based on usage of GSEvent (sending clicks to UI). You can look following questions. However, as I know, in iOS 7 these API became protected by entitlement. So, this method is dead (most likely).
Using GraphicsServices.h/GSEvent as well as compiling CLI iPhone tools with Xcode
Use GSEvent to send touch event,but it's invalid.
Simulating System Wide Touch Events on iOS
iPhone, how to fire a button event in programmatically
Apps can use region monitoring to be notified when the user crosses geographic boundaries or when the user enters or exits the vicinity of a beacon. While a beacon is in range of the user’s device, apps can also monitor for the relative distance to the beacon.
In iOS, regions associated with your app are tracked at all times, including when your app is not running. If a region boundary is crossed while an app is not running, that app is relaunched into the background to handle the event. Similarly, if the app is suspended when the event occurs, it is woken up and given a short amount of time (around 10 seconds) to handle the event. When necessary, an app can request more background execution time.
For detailed info:
https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/LocationAwarenessPG/RegionMonitoring/RegionMonitoring.html#//apple_ref/doc/uid/TP40009497-CH9-SW1
There are two scenarios: you either want users to be able to do something with your device other then use your app, or you want them to always be locked into your app.
In the former case you should trust user. Just show the push, timer or location notification and let them decide to launch the app or not.
In the latter case just lock the device using guided access mode.
I'm spec-ing an iOS app (which will be built outside of our company) which will upload a user's data entry to a server. If the device is not connected to the Internet, we'd like to save data on the device and upload it when the network is re-connected. (The app will primarily run on iPod Touch devices that will be disconnected most of the time).
If the user unlocks the device and re-opens our app after the network is reconnected, then uploading to the server should be easy because the app is running.
But what if the app is not running, where "not running" can mean one or more of:
device was power cycled
user has locked the device and it's sitting in his pocket
app crashed
user exited the app
user started using other apps so our app isn't running in the foreground anymore
are there other cases?
In the cases above, is there a way (ideally a battery-efficient way) to ensure that local data is uploaded soon after Internet connectivity is restored? Is the answer different depending on which of the cases above caused the app not to be running?
And is there a minimum iOS version the device will need in order to enable some (or all) of the above not-running cases to still upload when the app is not running?
My apologies if these are obvious newbie questions-- I'm not an iOS expert.
There is an interesting technique that is used by among others Instapaper and News.me(the pioneers of this technique) where you use region monitoring to initiate background downloads or uploads. Marco (Instapaper) blogged and talked (in episode 80 of the Build and Analyze podcast) about his communication with Apple so it should be a allowed in the App Store.
In brief the technique is that you set up certain regions (geofences) like "home" or "work" and respond to the locationManager:didEnterRegion: (and similar) callback(s). Your app will wake up from the background once you enter the pre-specified region and you can check to see if there is any data to upload.
This technique won't guarantee that the data is uploaded when the network reconnects but it will allow your app to automatically upload the information when the iPod Touch users gets home to their WiFi network.
That should most likely be at least once a day which may or may not be frequent enough for you. You could add a timestamp to when the initial upload was attempted and send that along the upload once it succeeds to get the correct order of events (data entries) on your server.
There is no way to ensure this. If your application is "not running" (by the definition described in your question), it will not be capable of responding to a change in the device's network status. It should be setup to resume upload operations the next time the application runs again.
EDIT:
Some of the cases you've described may indeed provide different opportunities for your application. Specifically, if the user "exits" the app by pressing the home button or launches another app in the foreground, your application may continue to run the in the background and could potentially respond to a change in network reachability.
The nature of what may be done in the background and for how-long is well documented, and supported by any version of iOS that supports multi-tasking. I recommend you review the documentation pertaining to App States and Background Services.
device was power cycled --> really NO WAY of resuming, unless you open the App!!!
user has locked the device and it's sitting in his pocket --> apps applicationStatus is UIApplicationStateInactive but it is running in the background. You still are able to react to notifications and i.e. accelerometer events. Try the Reachability Class and Log the changes!
app crashed --> NO WAY, unless opening the App
user exited the app --> App is sitting in the background. There you have a maximum of 10 Minutes Restriction of fully using your App (like the App "Pastebot" does)
user started using other apps so our app isn't running in the
foreground anymore --> Same as user exited the app
On multitasking Apple says the following:
Real multitasking only for certain kinds of usage, as there is Audio Background playing, VOIP (like Skype), navigation applications
All the other apps can request a specific amount of time after the app is closed/in the background, to finish certain tasks (as sending an email, sms or uploading/downloading important data)
Important Quote from dev docs:
Your app delegate’s applicationDidEnterBackground: method has approximately 5 seconds to finish any tasks and return. In practice, this method should return as quickly as possible. If the method does not return before time runs out, your app is killed and purged from memory. If you still need more time to perform tasks, call the beginBackgroundTaskWithExpirationHandler: method to request background execution time and then start any long-running tasks in a secondary thread. Regardless of whether you start any background tasks, the applicationDidEnterBackground: method must still exit within 5 seconds.
If you're building a restful API then I would recommend using RestKit, it has a request queue that checks the network status on the device and starts uploading once network access has been assured. You can read more about this here: http://mobile.tutsplus.com/tutorials/iphone/advanced-restkit-development_iphone-sdk/. Read the sections about Request Queue and background download/upload. It should be noted that RestKit is a big library which has it's advantages and disadvantages. I'm not completely sure how this que works with the app lifecycle, if it saves the request que even if the app is terminated. You would have to investigate that. RestKit does support background uploading/downloading, but as already noted, I think it's impossible to do any uploading if the app is terminated and not in background state.
I wouldn't recommend using RestKit if the API isn't Rest though.
You can download and experiment with RestKit here: https://github.com/RestKit/RestKit.