I am working on a medical related app where a medical device interfaces via bluetooth with an iphone. However I cannot figure out how to allow the app to run indefinately in the background. Right now it only communicates when the app is open. I have been reading a lot of questions related to this and I haven't managed to find an answer which fits. I'm sorry if this is a duplicate. Can someone point me in the direction of how to implement this.
ETA - I just got confirmation that this is supposed to be able to go on the App Store.
Did you come across this question: Background time issue for Bluetooth LE app for Iphone 4s
It seems that adding the background mode bluetooth-central (see documentation) can enable your app to run in the background while handling bluetooth events. As noted in the question above though, you could always set background mode to audio and play a blank looping audio track to keep your app alive and responding if you don't need to be on the App Store.
Related
Might be i am using a wrong title but i will try to explain here what i want.
In iOS i need to implement a functionality to get notify if the user is using their iOS device.
My app will be running in background using location services and i need to find out if the the user is using their device. It is doable as i have looked into this application which is sending notifications in background to the drivers who is suing their devices while driving.
https://itunes.apple.com/fr/app/cellcontrol/id661169580?l=en&mt=8&ign-mpt=uo=2
So i need similar kind of functionality to find out if a user is using iOS device or not. If anyone of you can suggest me any approach then it would be great for me to start.
Thank you!
Note: I have tried to find out touch events in background but that is not possible as i have done some research on this.
You won't be able to receive touch events when the app is in background using public API's. However, you can do that with the help of mobileSubstrate library ( http://iphonedevwiki.net/index.php/MobileSubstrate - The MobileHooker component is the one that would be used). by hooking your process to the OS. As an example, the display recorder app in Cydia tracks global gestures while recording the screen. This will be a cydia tweak and you will need to jailbreak your device to do all that.
Coming to your specific use-case, the example app you cited should be using one of the exceptions for background applications mentioned in https://developer.apple.com/library/ios/documentation/iphone/conceptual/iphoneosprogrammingguide/ManagingYourApplicationsFlow/ManagingYourApplicationsFlow.html (see the section - "Implementing Long-Running Background Tasks"), probably the one to receive updates from external accessories.
Is it possible to flash a flashlight in iPhone when application is background mode?
Please give some suitable suggestion.
Already given the answer similar of your this question, pls see this link at once
Iphone flashlight not working while app is in background
This is a normal behavior.
Apple's sandboxing will not allow you to keep the flash on while your app is in the background.
There is no workaround unless we are talking about a jailbroken app.
Edit:
Apple is very strict on it's system's APIs usage. Especially when it comes to:
- User privacy
- Battery life
- User experience
In the case of the flashlight, the last two items are relevant. Apple will not let an app drain the battery when not in the foreground and iOS users are used to the fact that flashlight, camera, microphone... are immediately disabled when going to the background (with an exception for the microphone in some background modes cases).
To answer the comment on your initial post, iOS controls your hardware. So since Apple decided they don't want the light to stay on when the user closes the app, iOS will just power off the flash when your app goes in the background. Your app has no authority to prevent it.
When in background your application doesn't work or get any messages from the system.
The only cases when this is allowed are:
navigation application
audio player
Internet telephony
Unless you are designing any of the above you can not flash the user with anything.
If you only want to notify the user about something, you can create a notifier that will pop a message in the users window even if your application is in the background or entirely off. the user can click the message and then he will be back to your application
My app is an audio player, so it keeps running in the background. But flashlight works only when it's in the Foreground. No flashlight from the background.
try AVCaptureDevice
AVCaptureDevice
I know this question may be a little bit common and over asked but I cannot find any precise information... so :
Is it possible to have some kind of thread running when the app is in background so I can perform basic sync with my webservice ?
App is in background : I mean the user clicked the Home button, or switched to another app
basic sync : photo upload and download with AFNetworking. I know it has method to continue an HTTPRequest while app is in background, but this is not my point.
My goal would be to make some kind of sync manager, reading a list of photos to update created while the user was on the app, and perform those changes.
I know that the manager could be killed by the OS, but since my server uses atomic transfers it is not a problem. I just need a way to relaunch it... Push ?
I think apps like Google Latitude or Mail and those kind of apps uses what I am looking for but I cannot find any relevant details on it. And using iOS5 is not a problem but waiting for iOS6 would not be a solution.
Thank you for your replies !
PS : well I almost forgot. the app is designed for an enterprise program, so maybe rules are different ? I don't think there is any check for in-house deployment so it might lead to new possibilities...
Apple's Mail client has a background daemon which keeps it running but you can't have that with your own applications. Once an app enters a background state, it must halt it's operations. You can request for a little more time when backgrounded to finish off any transfers or writes to disk (see the Executing a Finite-Length Task in the Background section on Apple's Multitasking Guide)
Google Latitude has events generated based on location. This is a special type of backgrounding introduced by Apple for certain types of applications (see Implementing Long-Running Background Tasks section on Apple's Multitasking Guide) but this can't be used for HTTP syncing. It can only be used for audio, location, voip, newstand content, bluetooth and external hardware attachments.
Push doesn't seem like a solution because it only generates an alert. It doesn't trigger any action until the user triggers the opening of the notification.
You'll want to read Tech Note 2277 Networking and Multitasking.
Basically you have a couple of options:
If you can convince Apple that your app is a VoIP app then you can register a VoIP socket and the OS will resume your background app whenever there is activity on that socket.
Your main option though is to register a background task for any outstanding activity that you have to do when your app is put in the background. You typically get 10 minutes to finish up that work.
Mail is a special app with privileges you don't get.
Apps like Latitude typically register themselves for location updates, specifically to be woken up when there are major geo-position changes. Apps that record GPS tracks do similar things.
Found it !
Using Suhail Patel 's link on Apple's Multitasking Guide I added the voip tag to UIBackgroundModes in Info.plist and use setKeepAliveTimeout:handler: method of UIApplication to relaunch it if needed once the app is going to sleep.
I hope this will help a lot of you !
Of course this app won't be allowed to be on the App Store but for in house development this is in my opinion the best way to do so.
Thanks everyone for showing me the right direction !
I have an application that requires location tracking and I think it fits squarely within one of the allowable background models. However, I need to post to a network service when there are significant changes of location. I've seen write-ups that state network access is prohibited in background processing, but I didn't read that in Apple's docs.
Does anyone know if it's kosher (wrt Apple policies) to make occasional and very quick network updates in a background process?
Good point, according to the Apple documentation only the following usages are allowed in background and each service should be registered:
audio—The app plays audible content to the user while in the background. (This content includes streaming audio or video content
using AirPlay.)
location—The app keeps users informed of their location, even while it is running in the background.
voip—The app provides the ability for the user to make phone calls using an Internet connection.
newsstand-content—The app is a Newsstand app that downloads and processes magazine or newspaper content in the background.
external-accessory—The app works with a hardware accessory that needs to deliver updates on a regular schedule through the External
Accessory framework.
bluetooth-central—The app works with a Bluetooth accessory that needs to deliver updates on a regular schedule through the
CoreBluetooth framework.
Other than this services, you can create a Finite-Length Task in the Background that actually give you the possibility to end a network process.
This can be important if your app is performing some important task,
such as writing user data to disk or downloading an important file
from a network server.
Regarding your question, it's not really clear if you can or not can do a quick network connection if you've a location service running in background. I would say YES for a short connection, but not totally sure. Since iOS 4.0 this usage was denied and clear in documentation, now that part has been removed.
Yes if you use background for just quick connection. Apple won't allow you to run in the background as you want.
NO If your app does not fall in the Voip, music or GPS category; then you can't run in background.
more here: Update my app when it is in background
You could use ASIHTTPRequest.
ASIHTTPRequest has a property setShouldContinueWhenAppEntersBackground:. default is NO, you may turn on YES so you have background network process.
Apple documentation seems a bit unclear on the strict policy. There are definitely applications in the app store that make sporadic network calls while running in the background as a location-based application. An example is the Geoloqi application.
Hardware Volume Control
I'm trying to understand what is best practice for apps that are mostly silent but occasionally produce sound. Such apps can take advantage of the side volume control on iOS devices and avoid the need to design in a NSVolume control widget, which I believe is not as convenient as the hardware side volume control. The approach would apply to apps like MapQuest 4 mobile where you get occasional audio prompts that blend well with other music players (using audio ducking) but are silent for the most part. I'm wondering how others are addressing this same issue.
I have developed such a system that works rather nicely. In my approach I query the audio APIs to determine if other music is playing (iPod, AOL Radio, Pandora, etc.) then start an audio session only if no other audio is playing. This ties the hardware side volume control to the app instead of the ringer (for iPhones). The challenge comes when you go to the background. My approach kills (deactivates) the session in the background only if the app is not using audio. If there is audio playing the session is deactivated at the conclusion of the playback.
The idea behind killing the playback is to restore the user's ability to adjust the ringer volume to their liking should my app continue to run in the background.
This question originates from issues I faced when developing the voice navigation feature on MapQuest 4 mobile on iOS in 2008-2009. In this app we wanted the side volume switch to control the volume of the turn advice at all times while the app was running. I later realized that I could not control my ringer volume after arriving at my destination and sending the app to the background. This was years ago but I believe the app was continuing to run in the background which lead to the problem. It is an interesting case, when the user is navigating but sends the app to the background should you continue the audio session? Is is more likely that the user would like to change the app volume or the ringer volume while the app runs in the background?
My general use case (when I posted this question) involved navigating in the background while running another app in the foreground (commonly a music player). However it is also common for the navigation app to be sent to the background while the user sits on the home screen. This is when it would make sense to deactivate the audio session.
It is not as straight forward as it seems but my approach works for most cases. Still I am wondering if there are other more viable solutions to the problem. What are other people doing? Would it make more sense to just include the volume control in a view that auto slides in/out of place? Are there things that I have not considered? How have you approached the problem? Do you have any general suggestions?