I have written an app the uses the RealmDB, which produces a file called default.realm. This is the database storage file. I would like to setup my app to make use of the iCloud automatic backup feature. How can I setup my app to do this?
You can't! Because your app is already set up like that! :)
According to the File System Basics page on Apple's website, all files in an app's Documents folder will automatically be backed up to iCloud, or the user's local iTunes account if they've chosen such. This is on by default, and must be explicitly disabled through code if disabling backup is desired.
By default, Realm places default.realm in the Documents directory for this exact reason: to ensure any user-generated data stored in it will be properly backed up in through iCloud and/or iTunes sync operations.
So you don't need to worry! Your Realm data is already being properly backed up by iCloud as we speak! :)
Related
I was wondering whether my app's sqlite database will be transfer over to desktop when user sync the app with iTunes or do I need to do some coding to ensure that it will be transferred?
Please advice. Many thanks.
You can transfer the content of your document directory's document folder contents by adding UIFileSharingEnabled key to your info.plist.
Please check the below image:
After adding this key to your info.plist, when you sync your iPad with iTunes the documents inside the document folder will be listed in iTunes as shown below:
This is a nice tutorial for starting the iTunes filesharing: How to integrate iTunes file sharing
We not only can backup our files on itunes but also in icloud....
this is how the app data is persisted along the the app updation ,ios upgradation....
As you long you put your data files in standard locations within the app's sandbox and you don't explicitly flag the file as a file that shouldn't be backed up, then the data files will be backed up to iCloud or iTunes (depending on how the user has setup device backups).
It depends on your file scheme, you can decide which information is necessary and should be backed up and which one should not because it can be easily recreated.
Look for the "Where You Should Put Your App’s Files" section
http://developer.apple.com/library/ios/#documentation/FileManagement/Conceptual/FileSystemProgrammingGUide/FileSystemOverview/FileSystemOverview.html#//apple_ref/doc/uid/TP40010672-CH2-SW2
I have an app that allows me to download characters (images), sounds, etc. When the user chooses which character to download can I store that in a directory in my App Bundle? If not, where is the best place to store my content (data)? I was thinking the documents directory, but then I saw somewhere that Apple now wants data stored in the caches directory.
Thanks for the help.
can I store that in a directory in my App Bundle?
No, you can not modify the app bundle.
If not, where is the best place to store my content (data)?
If your app must support iOS 5.0 or earlier, you will need to store your app data in the Caches directory. However, keep in mind the files could be deleted in low space situations so your app will need to degrade gracefully if your app data is deleted.
As of iOS 5.0.1, you can store your data files in the Documents Directory and flag them as "do not back up". By flagging the files, your app complies with the guideline that apps are responsible for ensuring that only user data and not application data is backed up to iCloud and iTunes and avoids a possible rejection by Apple. In this case, the files will not be deleted in low space situations.
As of iOS 5.1, you can store your data files in the Documents Directory and use either NSURLIsExcludedFromBackupKey or kCFURLIsExcludedFromBackupKey file properties to exclude files from backups. Either of these APIs is preferred over flagging them as "do not back up". In this case, your app complies with the App Store guidelines and the files will not be deleted in low space situations.
I know that this is quite a long discussion, but you should probably read it. :)
The iOS Data Storage Guidelines state:
To ensure that backups are as efficient as possible, be sure to store your app’s data according to the following guidelines:
Only documents and other data that is user-generated, or that cannot otherwise be recreated by your application, should be stored in the /Documents directory and will be automatically backed up by iCloud.
Data that can be downloaded again or regenerated should be stored in the /Library/Caches directory. Examples of files you should put in the Caches directory include database cache files and downloadable content, such as that used by magazine, newspaper, and map applications.
Data that is used only temporarily should be stored in the /tmp directory. Although these files are not backed up to iCloud, remember to delete those files when you are done with them so that they do not continue to consume space on the user’s device.
If you have an OS X or Unix background, it’s easy to understand Apple’s position that such directories have no guarantee as to how long the data in them will persist.
The fact that the tmp directory in in the app’s sandbox is not the same as the root /tmp directory, should not make a difference how you think about this directory.
If you have never observed files being removed from these directories in the past, that is not a guarantee that it will not change in the future. Especially when the change is in accordance with documentation. This is a general rule.
Changes/gaps in Apple’s documentation:
As late as June 29, 2011 Apple’s documentation regarding /Documents said:
Use this directory to store user documents and application data files.
This is pretty clear. No wonder developers are unhappy that the rules for the Documents directory have changed in iOS 5 without any suitable alternative.
Regarding /Library/Caches:
Use this directory to write any application-specific support files that you want to persist between launches of the application or during application updates. Your application is generally responsible for adding and removing these files. It should also be able to re-create these files as needed because iTunes removes them during a full restoration of the device.
App review rejections
Developers are reporting that apps that store any/some/much data in the Documents directory are being rejected by App Review.
It’s unlikely that the App Review team has detailed knowledge of which files are being stored in which directory and which of those are user generated vs. data that can be downloaded again or regenerated. Some developers have reported success in responding to the App Review team with an explanation of how their app is storing data and how that is in accordance with the rules.
What is being backed up by iTunes and iCloud
Everything in the app’s home directory is backed up, with the exception of:
The app bundle itself (.app)
/tmp directory
/Library/Caches directory
Other documentation clearly states that the Application Support directory is also backed up by iTunes (and presumably iCloud). In the discussions some developers have suggested that Application Support directory would be safer (= more permanent) alternative to Caches. To me it seems that App Review would crack down on large amounts of data stored in Application Support with the same fervor as for the Documents directory, since it’s all about iCloud storage.
Changes in behavior in iOS 5
As of iOS 5, /Library/Caches may be purged while your app is not running if the device experiences a low disk space warning.
There is no longer a directory where your app can store files that are:
Not backed up to iTunes/iCloud
Not at risk of being purged
Downloaded content should not be stored in the Documents directory according to Apple's Guidelines:
Only documents and other data that is user-generated, or that cannot otherwise be recreated by your application, should be stored in the <Application_Home>/Documents
Use the /Library/Caches directory instead
Data that is used only temporarily should be stored in the <Application_Home>/tmp directory.
My use case is:
User downloads my app and uploads some data/Files onto iCloud within the sandbox of my app.
User deletes my app
Questions:
Will iClould keep user's data that was belonging to the deleted app? (Based on my experiment, the data is kept on iCloud when my App is deleted, however, I am not sure whether the behaviour is official).
If the answer is Yes, then I have the following questions:
a. How user's data eventually get deleted/cleared from user's iCloud storage? (My concern is that if the user decide never to use my app again, the data would become useless therefore should be cleared on iCloud to free spaces)
b. If user decide re-download my app, how can he get access to the data iCloud he originally uploaded?
c. Can I manage the user's data from iCloud web portal (www.icloud.com)? I don't see my uploaded document appears in iCloud web portal, even I put my files under "Documents" subfolder.
d. Is there any official documentation that describes this behavior?
Thanks in advance!
Yes, iCloud will keep a person's data belonging to the deleted app by default.
Follow up questions
A: The data will stay in iCloud storage until the person decides to delete the data. Using the Settings app, a person can manage their iCloud storage, down to turning off backups of each app's storage. Or the entire backup for a device can be deleted to start over with a fresh backup.
B: If a person reloads an app on their iOS device, meaning any app with the exact same App ID so it could be an updated version, iCloud should restore the data from the app's backup.
C: No, the iCloud Web portal only gives access to the apps loaded by Apple, currently Mail, Contacts, Calendar, Find My iPhone, and iWork. Apple could offer the ability to add apps to the iCloud Web portal, just like we add apps to our iOS and Mac devices. But that would be some future offering.
D: Much of this is documented in the developer documentation. Some of this answer is undocumented, and gleaned from experimenting with iCloud (so please correct me where I'm wrong).
I want to store a date string in the iphone device, but not in the application context, because if a user deletes the app then that value is deleted too.
Is this possible?
Store it in the keychain. Keychain data is not deleted when the app is.
A possible solution is to store all the information on a server. You could use rails, php, or any other server framework to do this. Also, there's a new service that's trying to make it so you don't have to do any server coding at all: http://www.parse.com
If the application gets deleted on iPhone, all its related files are also deleted. Including files, SQLite databases and preferences.
If you want preference to persist after deletion, you will need a server and allow the user to store that information there (in the cloud).
i want to save a file outside of my application bundle as a backup of database so that when user reinstall my app or my app crashes he can backup his data from that location.
Apple already does this, with iTunes.
What you are asking is technically against apple's policy, unless you store it off site, on a server (which you could easily do)
If you have a lot of applications, I'm not aware of the policy, but perhaps you could make an app to back up your other app's data.