I'm using background geolocation to schedule local notifications when the user is in a specific location.
Since theses notifications are link to a commercial operation I've got a date, stored in the userdefaults to manage when I should disable the background geolocation when the operation is other.
I don't want the user to have to launch the application to be able to disable the significant changes monitoring.
So I tried to stopMonitoringSignificantLocationChanges the CLLocationManager directly in the locationManager:didUpdateToLocation:fromLocation: but it doesn't seam to work.
Any advice? What is the best practice for this issue?
Thanks.
Given the rules of the road for backgrounded applications or apps that aren't running, your hands are somewhat tied here.
Here is your one and only option if you want to disable location without any interaction from the user.
Each time your user's location updates from the background, your location manager delegate will receive this update. You don't get a lot of processing power here, so keep it short and sweet or register for a long running background task, check your date and if you are done with location, call the stop monitoring call there, reset any data or flags in your user defaults and you are done.
If you trigger from a local notification, the user will need to click on the open button to perform any actions. You can fire notifications from your background location delegate method for sure. But that is your one and only path to automating anything without user interaction. What you do there is up to you. There is no problem with checking for location udpates and turning that off from the background delegate method.
Related
I have a situation where I have to present alert while my app is in background.
So I was thinking that the solution is Local notification.
But the problem is that, I want to show that alert only when user has crossed a particular predefined location point.
So I have to show the notification without any registration for it in Foreground(Or you can say register the local notification in background).
Is it doable ?
Please help.
Yes, you can let your run in the background while you still receive location updates.
You have to the add location to UIBackgroundModes in your apps info.plist;
And any instance of CLLocationManager will keep receiving location updates.
But be aware that this could drain the battery of the iPhone really fast, so it's a good idea to only monitor major location changes.
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 can get the current location of my iPhone but I was wondering if it is possible to call my methods when application is in background and pop-up message(may be using local notification?) if user has reached at particular location.
Thanks.
Yes, this is possible. A local notification is also an excellent solution.
All you need to do is to set the flags for background position updates in the app plist. Then, in the callback methods for the location manager, perform the distance and/or location tracking logging and fire a local notification.
I am writing an application that records a users position at regular intervals whilst walking. I am using an NSTimers to schedule "startUpdatingLocation" followed by calling "stopUpdatingLocation" shortly afterwards to save as much battery as possible.
I want the user to be able to start the application and lock the phone thereby putting the application in an inactive state. My question is when this happens my application (when running via Xcode) seems to continue as normal, but I am curious if there are any differences in the way the application runs in this state as apposed to when the application is running as active?
From the docs it only mentions "applicationWillResignActive" with regards to the application passing through that state on its way to the background. I am more interested in how an application behaves when a used locks the UI and puts the phone away, I just want to make sure its going to keep doing what it should be doing or do I need to take extra measures?
When you app hits applicationWillResignActive it can continue to receive location updates if you use the UIBackgroundModes option in your apps info.plist.
Add the location key.
It is important that you do not use a timer in the background as timers will run but hold their "fire" until the app becomes active again. Thus you will only get one read when the user comes back to the app. The GPS location accuracy level is what will drive how much the battery is affected.
In your app description in the App Store, Apples requires:
Continued use of GPS running in the
background can dramatically decrease
battery life.
You app will not be allowed to go live until the above text is in the description for the user to read.
You should definitely be testing this on a device. The simulator doesn't auto-lock, for instance.
applicationWillResignActive is called when the user presses the home button, when another app fires a notification the user accepts (including when a call comes in), and when the device locks.
Look into the multitasking documentation, and what it has to say about background location updates.
My suggestion is that you conserve the user's battery by:
- starting a timer, which when fired, starts location updates (and stops the timer)
- when you get an adequately-accurate position record, stop location updates and restart the timer
- if location updates fail, restart the timer for a longer period. Maybe they're underground.
The most efficient approach is using significant location update service while your application is in the background or the screen is locked on your app. You might get one update every ten minutes or so.
Remember also, the user can disable your app's location services permissions. Especially these days...
I'm developing an application that needs to take action on completed phone calls, preferably right after the call ends but minimally once per day.
I've read up on the new CoreTelphony framework, and it seems I can get call events if my app is active, but I don't see how to launch/wake my app when a call ends if my app is not the foreground app. I also don't see how any of the new pseudo-background "modes" would allow my app to listen for these events in the background. Do any of you know how this might be done?
If post-call processing isn't possible, then I'd like to figure out a way to automatically wake my app up once per day, pull all of the call events since the last wakeup, and process them. I know how I might do this with Push or Local notifications, but my understanding is that those require user action to continue; in this case, I just want the processing to happen automatically. Is there a mechanism that would enable this?
Thanks,
Dan
You can't launch your app without user interaction.
Push / Local notifications aren't for this kind of thing, they're for letting the user know about event.
On a non-jailbroken device there is no way to do what you want to do.