My app is an emergency app. It will be used by people in emergency and disasters.
It's possible that they got stuck in situations where they just don't have the time to enter or draw their password on the lock screen, launch the app and push a button. Is it possible that my app can ask the OS to launch the app if user throw their iPhone up in the air or shake it vigorously or something else.
What I wish to achieve by this ?
I want that OS launches my app in background if the user say shake his/her iPhone vigorously. Once launched my app will make a network request and keep running in background for short time.
PS:I think it's possible with the accelerometer.
Accelerometer will not work because Apple doesn't allow background processes opening apps. In your case, user must be opening the app by himself/herself manually. (PS. As far as I know, it's possible in Android)
iOS background tasking problems aside:
Apple don't allow apps that encourage the user to do things that might damage their iOS device. So your 'throw in the air' idea is out.
As for shaking the device -- this just isn't practical. What if the device gets shaken by accident? You've then got false alarms to deal with.
The crux of the issue is that something that triggers an emergency response should be a deliberate action which is hard to do trigger by accident.
This cannot work - and here's why.
Your app would need to run in background to handle motion events. Apps running in background can get killed at any time, i.e. if memory gets low. There might be some restrictions about running and and resource usage as well.
An app in the background cannot bring itself to the front.
Launching from a locked screen would bring great security risks.
Throwing into the air seems like a gesture that can easily be triggered by accident.
I must admit that I'm pretty happy that those apps are not allowed on the AppStore - as it would open many doors that I'd like to see kept close.
Related
I have a Timer which plays AVAudio at a specific time while the screen is locked (app in foreground when locked and plist setting 'Application does not run in background' set to YES).
When I run my code while my iPhone is connected to Xcode it works as desired, playing audio while locked even when the iPhone has been locked for hours.
Now if I disconnect my iPhone and just open the app by tapping the icon the audio won't be played if it's set for more than a minute.
Is there a difference that causes this problem? If I would publish my App to the AppStore which behaviour would my users get?
That 'Application does not run in background' flag is a very old flag that means your app does not support multitasking and should be terminated when the user presses the home button. There's no good reason I can think of to set that flag on a newly developed application. Unless you understand exactly what it's for and are positive that setting it to yes is the correct thing to do, don't do that.
(That flag was added when iOS 4 was released, to allow apps that could not handle multi-tasking to request the old terminate-on-home-button behavior from iOS 3. Given that we're now 6 major iOS releases from iOS 4, it seems outdated.)
So remove that flag. It probably doesn't have any impact on your question, but remove it or set it to no in any case.
If you want to run a timer while the phone is locked and play sounds at designated times then you will probably need to set your app up as a background sound player, and ask for more background time when you get a message that you are going to the background.
That being said it's likely that Apple will reject your app. Running a timer from the background means that the processor on the phone has to run at full speed all the time, which will DRAMATICALLY reduce battery life.
Apple only allows a very small subset of apps to run in the background, and then only under specific circumstances (like a background sound playing app when the user is actively listening to music, or a navigation app that is actively tracking the user's location and notifying them when it's time to make a turn to follow directions.)
Should be no different. If you'd like to feel what do your users' feel then you can publish it to TestFlight which is the best app beta test environment. Find some testers or try it yourself.
The directions should be to verify the playing logic and the sound file relationship which link to the connection.
Is there any possibility to know which apps are in the background (Those apps that appear when you double tap home button)?
For 3rd party apps, no. Not in a reliable, App Store safe, future proof way. Think of your app as siloed, unaware of what else is running, and you'll be pretty much in the mindset Apple want (and try to technically enforce).
For other apps developed by you, you can use shared containers to write load/unload data each time one of your apps opens/closes, and work out what's currently running.
This is not possible on iOS with public api. There might be private api calls that do this, even though I don't think you will have access to them while running in the sandbox. This however might be possible on jailbroken devices, but you will not be able to submit to the app store with such api usage, unless you know how to hide that from apple.
Also please note that apps shown in the app switcher are not necessarily running. The app switcher shows every app that has been running in the past which the user didn't force-quit. If the user does not force quit an app, every app that has ever been launched is shown in the app switcher. If iOS decides to terminate an app because of memory needs, the app is still shown in the app switcher. This is one of the reasons why everyone should implement state restoration, as the user does not know whether an app is currently running or not!
I am working on a VOIP app and need it to auto-start when the iPhone starts up. Everything works 80% of the time. But 20% of the time the app fails to startup. One test scenario is the following:
Open app and type something and save
Reboot phone
Check if app is running by double-tapping the home button but DO NOT open the app.
If app is running, reboot phone again and see if the app comes up again in the background process.
This scenarios works most of the time but not always. Other scenarios also fail at times. Can someone clarify if there is a fool-proof way to start a VOIP iOS app every time the phone boots up?
Thanks.
No, it can't be done. If a user force quits an app, it stays force quit. That's how apple want it, and that's how it's going to be. You can't circumvent the users wishes with multitasking. Also, it's worth knowing that what you see in the fast switcher is not necessarily everything that is running, it's what ios thinks the user should expect to be running ie it may shut something down in the background of its own accord in order to free up resources, but because the user did not initiate it this app will appear to still be open in the switcher, despite that it is not.
Sorry, you can't open an app on startup. You should include a reminder on the app's first start up for the user to keep that app open in the background.
This is a strange one, I have a need to create an iOS app that runs in the background on an iOS device, but can not be visible on the Home screen of the device. The app may need to show up in Settings to configure a few options, but it mostly needs to run behind the scenes.
I do not need to publish this app on the app store, it is strictly an enterprise app for my company.
Does anyone know how this kind of behavior might be achieved? Configuration profiles? API's? etc?
Edit: Jailbreaking the device is not really an option for us. We have to keep the devices as they are.
Backgrounding
There are several methods to get permanent background execution:
a) Silent audio which is mentioned by JRG-Developer
b) Usage of beginBackgroundTaskWithExpirationHandler + turning location manager on/off (it will reset remaining time to 600 seconds)
Making app invisible
You can use SBAppTags in Info.plist (take a look at this: How to remove app icon programatically from jail broken iPhone app?)
It will make your icon not visible on Home screen.
I've no idea how you can tackle the not be visible on the home screen criteria, but there are certain services that are allowed to be run in the background continuously, notably:
Background Audio (even silent audio)
While this is indeed very hacky, short of jailbreaking the devices, this may be your best bet.
While it's unlikely / very difficult to get past the review process, in the event for some reason you do need to (attempt) to publish this app to the App Store, some apps are even available on the App Store which take advantage of this hack, such as PasteBot.
You should definitely read their write-up here about getting their app's Cut-and-Paste functionality to work while in the background:
http://tapbots.com/blog/pastebot/pastebot-music-in-background
Another out-of-the-box idea, why not use Android devices instead, which do support multitasking?
Two methods:
Jailbreak. A jailbroken iPhone is essentially a Mac and you can use all Mac UNIX programming tricks - spawn a daemon (you can even ask launchd to do that), or something. You can set up enteprise-wise Cydia source. Refer to saurik's website for a walkthrough and set up an experimental server using Ubuntu (which used apt too)
A non-jailbreak way may be possible, but it will depend on what your app is doing. You can try use enterprise-wise push notifications.
Given that this is impossible to do on non jailbroken phones, I'd suggest the following:
develop a directory app, or a phone list app, something that is specific to your company.
have it connect to a web service once a day to register the device ID (so you know the user has not deleted the app)
tell users they need to keep the app open at all times (and if a user's device does not register one day, send them an email asking them to launch the app).
Now you can send back whatever you want with the app. If they kill it, you'll know the next day when you have a script look at the logs.
If you think this is a terrible idea, it is, but its the best you are going to get on iOS right now.
EDIT: you could send a notification every day - say in the AM - to make sure the user opened the app if it wasn't running.
From my experince, this kind of behaviour cannot be achieved on iOS. When an app enters into background, it is active only for a small particular amount of time. After that, it goes into hybernate state. It stops working. So the behaviour you said can not be achieved without abusing iOS workflow. Thats why some call iOS's multitasking as not true multitasking. Only jailbreaking might help your case. That was for one case. The second one where the app cannot be seen on home screen is again, impossible. It has to be on springboard to run.
I would like to figure out if it's possible to create an app which, after launch, will switch to the background and will be basically a "timer" to control turning the device ON or OFF (or maybe just regaining control and be "in the user's face") when 30 minutes have elapsed.
I do understand that an app like this is not going to be approved ever. And I would like to NOT jailbreak my iPad. To give a bit more context -- I just want to limit the time children can use the iPad. I do have an iOS dev account, so I can sign the app, use a provisioning profile with my target device, and install it there.
Is it possible, and where should I be looking into this? Obviously it's not a part of iOS SDK.
If you want you could make something with push notifications (for example, after 30 minutes on iPad you will see "it's time to leave iPad and eat breakfest"). You cant make app which will "open" after time. Everything in background is very limited by iOS — there are push notifications and they should be used for every event.
If you want to do it you must jailbreak your iPad.
Edit:
I have a great solution for you.
Make a Web application that connects to iCloud and remote lock iPad. I have tested it and it works great — when you are doing something it is closing app and you must enter pin. Your Web application should turn in every minute and check if time has passed.