I want to invoke a method daily at a specific time in my iPhone application.
How can I achieve this?
There's not a whole lot you can do with the iPhone SDK and a closed app. You can have it send local push notifications at specific times, but that won't execute your code until the user manually opens your app.
See this related question recently asked: Is it possible to have my closed app run code in iOS?
One thing I've seen apps do (like alarm clock apps, etc) is have you leave your app open and just let the phone fall asleep and then it will still execute code when you want it to. But that only works as long as the user doesn't hit the home button.
Schedule a local notification. This is how most basic alarm apps work. The app needs to be running sometime before the method execution time to schedule a local notification. After the local notification has been scheduled, the app can be closed and the method will be invoked at the specific time.
If you have push notifications configured, then your app does not need to run at all to schedule the method. It can all be done from another application.
Check out this documentation on local and push notifications from Apple.
you cannot run a specific code inside your application when its not running ..iOS allow only limited functionality to be run in background or when app is quit.
Related
I have a problem about detecting sleep date and saving it. The thing is I want to run a counter, when you open the app it always count how much time passed and based on that calculates something. The thing is I want to stop counting if the computer is going to sleep. Is there any way to do this in background if the actual desktop app is not running?
I have tried NSWorkspace.willSleepNotification, but its not called if the app is not running, I also tried to do this in a menu bar app if its only an Agent its also not called, maybe its not possible to do.
You need to improve your question by showing us some code, so that we can help you with what you are doing wrong. I have a background app without a menu bar and I do get these notifications. And yes, you will ONLY get this notification if your app is running. What I usually do I create a background-only app to register those notifications, which I will pass to the main app, via a file or an Apple Event.
I have an iPhone application like facebook for iPhone. My application must connect my server and read all message every two hours regularly. I have a thread to read all message but when the application is terminated the thread cannot work. Can the thread run undependently from main delegate or how can I find solution for this problem?
You cannot have your app do stuff in the background. There is an API to finish tasks like uploading a photo but even that will be killed after around 10 minutes.
But the Apple Push Notification Service seems like the most appropriate solution for your problem. Your server notifies the device that there is something new happening and you fetch the actual messages when the user opens the app.
edit: As of iOS 7 Apple implemented a feature where you can schedule running tasks to fetch data in the background. Those tasks are not guaranteed to run at any specific times. See the release notes for iOS 7 and the linked methods below:
Apps that regularly update their content by contacting a server can
register with the system and be launched periodically to retrieve that
content in the background. To register, include the UIBackgroundModes
key with the fetch value in your app’s Info.plist file. Then, when
your app is launched, call the setMinimumBackgroundFetchInterval:
method to determine how often it receives update messages. Finally,
you must also implement the
application:performFetchWithCompletionHandler: method in your app
delegate.
There is no solution.
Apple does not permit applications to run in the background unless they are of a specific type such as location or audio or voip or newstand (your app can continue to run for about 10 minutes after it was active if it uses shouldBeginBackgroundTaskWithExpirationHandler).
There is no workaround, many many other people have wondered how to do the same thing as yourself before, but there is no legitimate way. Your app cannot schedule any sort of periodic call home activity.
The only way your app can run once its gone into a suspended or terminated state is for the user to launch it, either explicitly or in reponse to a local notification or remote push notification.
Is it possible to get a notification (that launches the app) when the network gets available?What I want is my application to update its contents as soon the internet gets available.The only way I can think of is to send a push from the server once is a while (may be once a day)and that tell the user it might be a good idea to get yourself synchronized.
This is currently impossible if your background task scope is limited to that feature. The only way you could do this is if you had some other legitimate reason to become a background app (aka VOIP or GPS) and run reachability checks every X minutes, and then post a UILocalNotification that allows the user optionally open the app (you cannot programmatically open your app yourself).
Let's say that my app in iOS is closed. Would it be possible to set it up so that it runs a piece of its code after a certain period of time?
You can have your app schedule push notifications, but you can't schedule it to run specific code unless it's running.
Short answer: no, you can not. At the most, your application will keep running in the background for 11 minutes, if you request the extra time (check the documentation for beginBackgroundTaskWithExpirationHandler on the UIApplication class). There are some things you can do: Schedule a local notification, which the user can use to launch the app, or use push notifications to remind the user of something he needs to know.
iOS allows background processing for the following reasons:
- location dependent functionality
- background audio playback
- voip
You can find out more from Apple's multitasking documentation
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.