I am doing a small application for iOS (with Qt and Native code)
I need send my position twice a day to a server (user REST API)
I have no ideas, I do not understand how I could launch a recovery twice a day in a service without my application being on.
Do you have any examples / suggestions to help me?
So far the solution I have found is to use the "background fetch" but I don't know if it is usable when the application is closed and not only in "background". And I also don't know if it's possible to use the locationmanager in this case. https://developer.apple.com/documentation/uikit/app_and_environment/scenes/preparing_your_ui_to_run_in_the_background/updating_your_app_with_background_app_refresh
Thank you
Background fetch wouldn't work if the app is terminated by the user instead of being in a suspended state in the background.
The same goes if you are using background location updates. https://developer.apple.com/documentation/corelocation/cllocationmanager/1620568-allowsbackgroundlocationupdates
I haven't tested if this would work but you could try setting up a silent remote push notification and send it to your app twice a day, then when the app wakes to deal with the notification you get the users location.
https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/pushing_background_updates_to_your_app
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.
This question already has an answer here:
Call a web service from iOS at a particular time daily in the background
(1 answer)
Closed 4 years ago.
I would like to know how to run a scheduled method in an iOS app.
Every day, I have to send the device location to a web service twice a day. This submission must take place at 12:00 and 18:00. I used the method startMonitoringSignificantLocationChanges but it did not help me, because it has no exact time to run (as the name implies, only significant change of location). This feature should be performed automatically without user interaction with the iPhone because it is an "automatic check-in". It must be carried out with the app in any status (running or in background or terminated).
I found solutions that use the local notification, but the process should be completely transparent, without the user having to check-in, otherwise the feature would lose the concept.
How can this be done?
Dasdom is right - iOS doesn't allow you to schedule a background task. You can request the app run in the background, but cannot control when your code will actually be run (per Apple's guide, "When a good opportunity arises, the system wakes or launches your app into the background..."
Your best option is to have your service post an APNS notification to your application and handle the notification silently by posting the location back to your web service.
NOTE: This app I am working on is completely for my own usage and will not be on app store so please don't give answers referring that.
I want my app to do some process in background or after termination (double tap the home button and swipe the app from applications multitask) every few minutes. The process is very very light and quick so it won't drain the battery. This process shouldn't require internet connection. I have seen some answers here like and I will explain what are the problems:
VoIP. The problem with VoIP is wither it should be in background to use UIApplication.sharedApplication().setKeepAliveTimeout(..) method which doesn't work when the app is terminated or it should be connected to the internet to establish tcp connection and receive commands from sever and as mentioned before I want it to be internet independent.
Location Services. I found this excellent site with some great articles but the problem is it only works when the mobile phone is moved more than 500 meters. It depends on the location movement so when the phone is staying somewhere there will be no code execution.
Playing an silent audio loop. The problem here is if the user plays another audio (which is completely possible like music or phone call) the app will terminate!
Jailbreak Launch Daemons. I can't require jailbreak so it should be solved with a non-jailbreak solution:(.
I am free to use any kind of private-API's and there will be no restriction for that.
Thanks in advanced
I also faced with such problem, and don't find any solution.
The main problem is if user manually terminated app - in this case you can't do nothing...
Only way is:
a) use Location Services (as you mention)
b) use Push Notifications with background fetch
I'm using Mailcore2 for an app that im developing by myself, and everything is perfect with Mailcore but now I'm trying to retrieve the emails when the user minimize the app (enter on background), I tried using background notifications but didn't work because time between the close and the first window to enter on my background function is too long.
So I tried to keep the idleOperation working when the user minimize the app but sometimes work perfect and sometime don't work at all.
Anyone have a solution to this?
I'm using Xcode and iOS 8.
Thanks.
The time slice provided by iOS for background fetch is based on an algorithm unknown to the developers.
If you want to use the IMAP IDLE operation, then you will have to start inside the performFetchWithCompletionHandler: and make sure you are done before the app goes to sleep again i.e. anything from a few seconds to max 30 seconds.
I would suggest creating an IMAP session as soon as you enter background, poll IMAP for new changes, process and go to sleep ASAP. But again, iOS decides when and how long you get that time slice for background fetch.
UPDATED ANSWER:
If requirement is just getting the notifications for new emails, then just register for push notifications on your app and push them from your server or use services like Pushwoosh.
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.