I want to know if it is possible to have two separate applications in iOS Domain where
1) One application is the background application
2) Other acts like Foreground application
The foreground application will use background application for fetching data, data processing and maintaining its database. The user will need to install both applications on his device and for this it should be like this that if user installs one app (say foreground or UI app) it will automatically guide user to install another app. Have heard that something like of this sort is possible in android and applications like voice recognization etc does that.
Also the background application will start running as soon as we boot our device and foreground will launch only after user launches it by clicking on the icon.
Possible advantages in my mind
scenario where one can come with more than one foreground apps. So both of foreground applications can use same background applicatons for maintaining database. This way there will be only one app maintaining database for two different foreground apps on a single device
The background will be the main app will be doing all heavy lifting such as fetching data from server, checking update at regular time intervals and maintaining data base.
Not sure if something of that sort is possible in iOS and is permissible on app store?
Thanks
I've never heard of something like this, especially not on an iOS device.
I don't think it will be accepted for one reason: two different testing teams will test each app. Because the apps require each other, neither app would function. If prompted to install the "other" app, testers would be unable to do so, because it would not be published, because the other team was unable to test it, because the original app was not published. (run on sentence).
It would be like a circle...
My thoughts...
What you are saying could be down with one app and multiple classes and in fact is a fairly common design pattern. You set up one class as the data model, and use background threads and process to keep the data up to date. The other class handles the user interaction on the main thread. Do a few searchs on Model View Controller design pattern and check the link below
https://developer.apple.com/library/mac/#documentation/General/Conceptual/DevPedia-CocoaCore/MVC.html
Related
I'm making an app that needs to run in the background. It plays online radio and at the same time must perform calculations.
I know there is a background expiration handler but it is very limited in time to my knowledge. Is there a way an app can perform calculations in the background for a very long time?
Someone mentioned something about specifying your app needs navigation and then it can keep doing important things. How?
From the Apple documentation:
Implementing Long-Running Background Tasks
For tasks that require more execution time to implement, you must
request specific permissions to run them in the background without
their being suspended. In iOS, only specific app types are allowed to
run in the background:
Apps that play audible content to the user while in the background,
such as a music player app Apps that keep users informed of their
location at all times, such as a navigation app Apps that support
Voice over Internet Protocol (VoIP) Newsstand apps that need to
download and process new content Apps that receive regular updates
from external accessories Apps that implement these services must
declare the services they support and use system frameworks to
implement the relevant aspects of those services. Declaring the
services lets the system know which services you use, but in some
cases it is the system frameworks that actually prevent your
application from being suspended.
Your app seems to be ok for the
Apps that play audible content to the user while in the
background,such as a music player app
While your app is playing music you can do the calculation you are mentioning. For more info check the Apple documentation here
Am developing application for calculate count of user moved steps and draw the user activities in the map. And we are using UIAccelerometer delegate for receive acceleration-related data from the onboard hardware. So I need to receive acceleration-related data when the application in background mode too. Last time one of my application got rejected because of using location service in background, Apple suggested me like "you can only use this background mode if your app truly needs this information to provide value for the user". Kindly suggest the best approach for this application.
You cannot run accelerometer in background.
You can track user's location in background... however, if you just keep tracking it and do nothing with that info.. apple is going to reject it and tell you to just get the lates location when app comes to foreground.
what you can try is.. update the user of total distance covered etc on a regular basis (like run keeper) and this will justify tracking location in background.
But first, you can try appealing to the review board explaining that you need to track location in background because you show entire route travelled by user when app comes to foregraound. and compare this to existing apps like run keeper and if you are lucky apple may approve your application without any changes...
This can easily be done.
What happens in that iOS put your application in halt state when your application is not in running in foreground state.
You just need to register your application for background execution.
Refer :
http://dcraziee.wordpress.com/2013/05/20/background_ios/
Also refer :
iOS background application network access
for apple policies about using location service.Which states that you can use location service in background.
I have an application that runs in the background, I need it to pseudo randomly take a picture using the forward facing camera and send that to a database.
A possible solution I thought of was to use URL schemes to open another application, which will take the picture and send it, then use another URL scheme to open the background application back up. Does anyone know if this is possible?
Or perhaps there is a better solution.
It is not possible for an iOS application in the background to initialize, utilize, or grab photos from the camera hardware, let alone store or upload them to a local database.
Not only is this a security risk, but it poses a potential privacy invasion, and is just plain creepy. Besides, background apps only stay alive for 10 minutes or so, so even if this activity were possible, sustaining it would be impossible.
However, it is possible to use the camera directly from an active app without having to delegate the task to another application (perhaps you are thinking a little too much like an Android developer :p). Take a look at UIImagePickerController.
There's a very limited set of actions background applications can do—GPS, audio, phone & VOIP calls, and a couple of others. Accessing the camera is not one of those allowed actions, so you can't take a picture in the background.
As an alternative, you could set up a notification system to alert the user that it's time to take a picture (for whatever reason), and if they choose to open the app it could do your required actions then.
I know with ios 4 it is possible to run application in background as per this documentation
http://developer.apple.com/library/ios/#documentation/iphone/conceptual/iphoneosprogrammingguide/BackgroundExecution/BackgroundExecution.html
this documents states that if application updates user's current location in background continuously then it is possible to run it in background.but is it necessary that we have to use only CLLocationManager for updating current location?can we user other apis like google latitude apis for updating current location?then also it is possible that application is able to run in the background forever?
As far as I understand from the document you posted, if you define the UIBackgroundModes with a value of location in your info.plist, "the system should allow the application to run as needed in the background". So, the first answer is yes, the application can run in the background and it will run indefinitely (up to battery life). This could be easily checked, actually.
Anyway, it seems to me that this kind of functionality is "reserved" to GPS-like apps and that Apple is really concerned about its usage:
For applications that require more precise location data at regular intervals, such as navigation applications, you need to declare the application as a continuous background application. This option is available for applications that truly need it, but it is the least desirable option because it increases power usage considerably.
so, I understand that Apple will screen really thoroughly all apps that activate this mode in order to assess if they really need the continuous update or do not (and in this case, possibly, the app would not be let in into the App Store).
Now, to answer the second part of your question, I think that one way that Apple will know if your app really complies with the rules, is its usage of CLLocationManager. The risk is that if you use another service, then Apple could think when reviewing your app that you just need background time without needing to constantly update the location.
But this is just a guess...
In the home page of my iphone app, there is a button added. When that button is clicked some other iphone app needs to be opened in a new viewcontroller (with out closing the parent app).There will be a back button on this view controller. When the back button is clicked, the new viewcontroller which is showing the another app needs to be closed and our parent app's home page needs to be shown.
Please give me some ideas on how to do this. I googled for this i didnt get any solutions.
Thanks,
Raja.
-- the following applies to iOS versions previous than 4.0 :)
Actually, there can be only one iPhone application running at once (with exceptions of Safari, Phone and some other system applications). The iPhone Human Interface Guidelines say so:
Only one iPhone application can run at a time, and third-party applications never run in the background. This means that when users switch to another application, answer the phone, or check their email, the application they were using quits.
However, if you only need to e.g. show a webpage, you can do it using UIWebView
Also, if you need to open another application, you should use URLs as pointed by Steve Harrison. This will, however, close your application. The recommended behavior in this case is to remember your application state and restore it when the application is run again, as Nithin writes.
According to apples documentation, they are not allowing any applications to be run in the background, except system generated ones. So you will be unable to do the thing you are going to implement. However, there is one thing that can make the same result.
You told that you are calling other application to run on a button click. Before initiating that application, save the current state of your application, may be using sqlite3 or core-data, and then open the other one. While returning back, load the pre-saved data from the database or wherever you have stored it. Every time you start the application, you check for the persisted data, if exists, load it or otherwise load your basic view
I don't think that you can run other iPhone apps within your own one. It doesn't make sense. You can open another iPhone app via a URL (see here and here), but this will close your app.
Like it has been stated: running two apps is not allowed by apple. You can however implement this apps features into you're app and have both get and save data to the same server...
Or like Nithin said: this functionality is available on JB iphones. Look into "backgrounder" for implementing one solution for normal users and one for thouse that has jailbroken.