When does data get restored for an app? What if I save data in the app's document directory. Then they sync with iTunes. Now iTunes has a backup. Will that data be populated to another device when they sync that new device to their iTunes or will they just get a clean install of my app? I'm trying to figure out how to keep track of a subscription in app purchase and was wondering if I could keep record in NSUserDefaults or some other local store.
Backups are per-device. So a backup of your iPod will not be restored to your iPhone. In other words, there is no sync.
Many times iTunes fails to create complete backup of all the iPhone data say it be contacts, message, mails etc. This type of problem may occur due to not installing iTunes properly. So, you should check whether iTunes have been installed correctly or not. In case there is no problem with iTunes then it is possible that you are trying to create backup of the files which can not be backed with the help of iTunes. To overcome with this issue you need to make use of iPhone backup application. By using this tool you will be able to prepare backup of all the files within minutes safely.
If the user backs up to iTunes, and then restores their backup to another device (maybe they lost their original iPhone), the contents of the app Documents directory will be put on the new device. Anything in the tmp folder won't be backed up or restored like this, but the Documents folder will.
However, that's not the best way to store the in-app purchase information. You should be storing that on your own server and keeping a count of the number of times the purchased content has been used. Inform the user that they can use it a certain number of times (say three) and after that they will have to buy it again. I'm not exactly sure of any details beyond that (like how to verify their identity) but it should get you started.
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I have two 50KB files saved in iCloud Drive. Using FileManager, saved in an iCloud container.
The problem is that they take forever to upload. I waited 2 hours and they are still in this waiting to upload status. Both my iPhone and iPad having this issue.
Is there a way I can force it upload? Or at least put it into priority queue.
I'm building a note app sync feature. And those slow upload makes sync impossible.
I ran into a problem like yours and tried to find the solution. So, I contacted directly to Apple Support.
Here's the suggestion:
First, you have to make sure that your OS version is up to date and your iCloud storage has enough space.
Next, you go to System Preference > Apple ID > uncheck a checkbox in front of iCloud then check it back.
I worked on app in which user can add images and make notes about those images, which i stored in sqlite and i store cards in document directory. I have enabled file Sharing option in app so user can keep backup of app's data manually in her PC via iTunes.
Please consider this scenario: the user connects the device from time to time to iTunes, and the synch process takes place. however, she does NOT go into the File Sharing option which is one way to backup manually the data in PC. now, she drops the phone in the bathtub and it does not work or due to some other reason she lost her device.
my question: when she gets a new phone, can she recover her data?
if yes, then how could we do this?
if no, then what is the correct way now to backup the third party app data.
If a user installs an an app which uses iCloud with a UI(Managed)Document, then uses the app, creates data which is saved to iCloud and then deletes the app on his phone, the iCloud data will stay on the device (transaction logs etc.). If the user reinstalls the app it will try to use these old files.
I have the following two problems with that:
The iCloud documents could have changed in the meanwhile and there might be problems when the user has no network connection on the first launch after reinstalling the app.
The iCloud documents for this app could have been deleted by the user (via settings or in Mac OS Finder in the user library). Now, when the user has no network on the first launch after reinstalling the app, the app might think that there is an ubiquity container with data even though it's already deleted (app might crash).
This is not very easy to test but I have definetely crashes and malfunctions for those two issues. E.g. NSMetadataQuery shows me results for documents which do not exist in iCloud because they have been deleted (but they existed on the deletion of the app).
Is there any easy solution to this? I thought about deleting the local iCloud data on the device when the app is launched for the first time - but how can this be done?
It can't be done. If you delete an iCloud document locally, you delete it everywhere-- eventually. The iCloud APIs have no concept of managing local copies independently of the iCloud service, so if you delete one-- even with the network down-- the iCloud ubiquity daemon will send a delete command to the service at the first opportunity.
The closest approximation that current APIs would allow would be:
Check whether the network is reachable
If it's not reachable, do not attempt to access any iCloud documents (because as you note, the information might be stale).
If and when the network comes up, try to open all existing iCloud documents. (On iOS, iCloud updates are only downloaded on demand, so you need to create that demand).
If that's not good enough (and let's face it, it's not good enough), file a bug with Apple and hope for the best.
My app is going to save a flag in the database (core data) saying whether the user is authenticated or not. How easy or difficult is to someone to access the "core data" database and change the information there without going through the App?
I am going to save a flag there saying "this user is authenticated" so he never has to authenticate again. This is a fun app, not a bank app, so I wonder if that's ok.
Putting in other words: Should I assume that a regular iPhone user (not jailbroken of course) will not be able to mess with the "core data" database and this database can only be accessed through its intended iphone app?
This isn't the kind of thing you should use Core Data for anyway. You should instead use NSUserDefaults or the keychain (depending on if you're just storing that flag, or associated user/password information).
The user defaults are there for storing settings, the keychain for private data. Use the right screwdriver for the right screw.
The iOS app sandbox is quite tight on-device. As such other apps won't be able to access your database, nor will the user on-device.
Application data in the app's Documents directory is backed up through iTunes, however. Though I've never tried such a thing, I can imagine a scenario where the user installs and runs your app but is not authenticated. He syncs and the user data is written to his computer. He opens the backed-up resource on his PC (iTunes does encrypt or obfuscate it) and figures out how to change the sqlite database or plist to show himself as authenticated. He then uninstalls the app on his device, then reinstalls it through iTunes, authenticating himself.
If the scenario is possible, you could potentially store the database in the cache directory instead, a directory that's not backed up when the device is synced with iTunes. It means the database would vanish if the user had to restore his device, but that might be an acceptable loss in your scenario, I don't know.
Edit
I agree with jer that the database isn't the best place to store such info, and if you're targeting iOS 3.2 and above, keychain is definitely the better place.
I don't believe a user on a non jailbroken phone would be able to mess with the data.
I'm currently in the middle of developing an iPhone app with a big reference database (using Core Data backed with a pre-populated sqlite database). Once the app is live and deployed to a client's iPhone, I need the facility to update/insert a small amount of data. What are best practices / methods for doing this?
There may be occassions when the frequency of updates will be daily for a month or so. Other occassions when a data update happens once every few months.
What is the recommended way of doing this? Note, I don't anticipate any data model changes for these updates -- this is purely an insert/update of data.
At the moment I'm starting to research the use of push data notifications (q:payload size restrictions?), app store updates (q:code/data model only, not data updates?) and the use of my own ad hoc data server (which the app connects to routinely to check for updates).
Can anyone please provide me any pointers on the above?
Thanks in advance
IIRC Push Notifications have a maximum payload of 256 bytes. Enough for notification purposes, but not more. Your app would still have to download the actual data from your own server after receiving the notification.
Note that the app bundle is not writable on the device. So if your app needs to update the data store, you should copy the pre-populated database file from the app bundle to the app's documents directory on first launch.
App Store updates would certainly be feasible (especially now that Apple seems to have gotten its review process down to a few days at most) but note that an App Store update will always replace the entire app bundle (code and data), so if your pre-populated reference database is big, the customer would have to download it in full every time.