iOS App Rejection due to 2.23 - Realm database - ios

Here's message from Apple:
2.23 Details
On launch and content download, your app stores 6.38 MB on the user's iCloud, which does not comply with the iOS Data Storage Guidelines.
Next Steps
Please verify that only the content that the user creates using your app, e.g., documents, new files, edits, etc. is backed up by iCloud as required by the iOS Data Storage Guidelines. Also, check that any temporary files used by your app are only stored in the /tmp directory; please remember to remove or delete the files stored in this location when it is determined they are no longer needed.
Data that can be recreated but must persist for proper functioning of your app - or because users expect it to be available for offline use - should be marked with the "do not back up" attribute. For NSURL objects, add the NSURLIsExcludedFromBackupKey attribute to prevent the corresponding file from being backed up. For CFURLRef objects, use the corresponding kCRUFLIsExcludedFromBackupKey attribute.
I checked my testing device iCloud backup and it is about ~0,3KB on launch.
I am using Realm.io database for storing data, but I set path of realm file to ..Library/Cache. Realm version 0.100.
change of path in code:
Realm.Configuration.defaultConfiguration.fileURL = NSURL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.CachesDirectory, .UserDomainMask, true)[0].stringByAppendingPathComponent("cache.realm"))
So I checked storage activity in debugger and also placement of file. But every option shows that files are actually saved in Cache folder and Documents folder is empty. Am I missing something ? What should I do next ?

Looks like you're writing something to the documents directory. What makes you think Realm is responsible writing to the user's documents? Are you perhaps using an image cacheing library which writes to the documents directory?
If you're certain that the documents directory is empty, why is Apple telling you otherwise?
If you access the Realm prior to overwriting Realm's default configuration, then it's possible you're actually writing to the documents directory until that time.
If you somehow confirm that Realm is writing to a different directory that you've specified, please file a bug report at https://github.com/realm/realm-cocoa/issues/new

Related

How can I get a non-expiring cache in iOS?

I'm using Cache framework for caching in my application. Cache framework can provide hybrid storage with expire option. I've set .never for both storages (disk and memory), but cache still can expire.
In my app i need to cache some Data() for forever, and update it if necessary (but not frequently). Speed of getting this cache is not that necessary.
Is it possible using this framework? May i need to use just DiskStorage, instead of Storage? I think it can expire, because it saving into system memory (which is RAM as i think) all the time, so iOS can clean it if needed, but can iOS clean disk storage?
So, i've found something about this in Apple Guidelines:
Use the "do not back up" attribute for specifying files that should
remain on device, even in low storage situations. Use this attribute
with data that can be recreated but needs to persist even in low
storage situations for proper functioning of your app or because
customers expect it to be available during offline use. This attribute
works on marked files regardless of what directory they are in,
including the Documents directory. These files will not be purged and
will not be included in the user's iCloud or iTunes backup. Because
these files do use on-device storage space, your app is responsible
for monitoring and purging these files periodically.
I wrote simple function for this:
func setExludedFromBackup() {
var url = try? FileManager.default.url(
for: .documentDirectory,
in: .userDomainMask,
appropriateFor: nil,
create: true).appendingPathComponent("MyFolder")
var resuorceValues = URLResourceValues()
resuorceValues.isExcludedFromBackup = true
try? url?.setResourceValues(resuorceValues)
// print(try? url?.resourceValues(forKeys: [.isExcludedFromBackupKey]).isExcludedFromBackup)
// you can check if your directory excluded from backup (it excluded if "Optional(Optional(true))" printed)
}
Yes, it's Documents folder, because other folders still continue to be cleared.
You simply call this func somewhere (i've used AppDelegate), and check if directory is already excluded from backup before calling it. That protect "MyFolder" in Documents directory from deleting, if iOS has ran out of memory! So my data will be available as long as i want to. But you must include after-time deleting mechanism too, because this data will never be deleted automatically and on-device memory space will not be released. In my case i just used Cache framework's expiry property
P.S. Im not sure how will Apple react to this, while inspecting your app for AppStore, so tell them about offline use in your app and what you did with documents folder, don't forget to describe your deleting mechanism. I hope that doesn't break Apple Guidelines and app will not be rejected.

What is the safest directory in iOS which can be used to download images/pdfs? [duplicate]

Currently i was saving my application data (Media) to the CacheDirectory i.e
/var/mobile/Applications/BEAFC76C-C450-4A3A-9765-A0385A9580F3/Library/Caches
and things were going fine. But recently i got a bug report that the application data has been deleted. When i searched over it, i got this Apple Doc. According to it, DocumentsDirectory should be the ideal place to store the User/Application data.
Put user data in the /Documents/. User data is any
data that cannot be recreated by your app, such as user documents and
other user-generated content.
And Cache should not be used to store the User Data that could not be reproduced by the application.
Put data cache files in the /Library/Caches
directory. Examples of files you should put in this directory include
(but are not limited to) database cache files and downloadable
content, such as that used by magazine, newspaper, and map apps. Your
app should be able to gracefully handle situations where cached data
is deleted by the system to free up disk space.
What should be the ideal place to store it.
EDIT:
I have an application that allows user to store Videos and Photos in the application. For that i used CacheDirectory. But i am getting bug reports that the Data (Videos/Photos) is getting deleted. What conclusion i draw is that the data is being getting delete by the Device itself in order to provide space.
Secondly i also wanna give the iTunes sharing function. So only the particular files has to be stored in the DocumentsDirectory. Some files can never be exposed and some has has to be shared. What should be the ideal way to store the files.
Use Documents (NSDocumentDirectory) for files you wish to share via iTunes.
Use Application Support (NSApplicationSupportDirectory) for files you wish to hide from the user but still be backed up and never deleted by the OS.
Starting iOS 5, Apple says that it's no longer a good thing to save all kind of files in Documents Directory - if you do that, your app will be rejected for sure because this folder is backed up to iTunes & iCloud, unless otherwise specified.
It says that we should save files into Caches or Tmp Directory - these won't be backed up, but it's not a good thing to do because files from these directories can disappear if low memory happens.
So I think the best think to do is to save the important files that you need all the time in your app into Documents Directory and mark them not to be backed up, like this.
Library/Application Support Folder is the folder you should be using.
This directory doesn't always exist, and thus you may need to create it.
You can enable or disable whether you want to backup this data with iTunes or not.
This data is not accessible even if you enable file sharing. Only data that you put in Document directory would be shared with iTunes sharing, so you can still protect your data and get it backed up as well. Apple's documentation

Backup document directory on iCloud without sync

How can I actually backup my app document directory by using iCloud, so that user can switch over iCloud accounts and get his app data, related to that particular account.
And my document directory contains sqlite database file and images.
I just read the iOS Data Storage Guidelines,
To ensure that backups are as efficient as possible, 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 Application_Home/Documents directory and will be automatically backed up by iCloud.
Data that can be downloaded again or regenerated should be stored in the Application_Home/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 Application_Home/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.
Use the "do not back up" attribute for specifying files that should remain on device, even in low storage situations. Use this attribute
with data that can be recreated but needs to persist even in low
storage situations for proper functioning of your app or because
customers expect it to be available during offline use. This attribute
works on marked files regardless of what directory they are in,
including the Documents directory. These files will not be purged and
will not be included in the user's iCloud or iTunes backup. Because
these files do use on-device storage space, your app is responsible
for monitoring and purging these files periodically.
As per guidelines, Application_Home/Documents will be automatically backed up by iCloud.
References and useful links
https://developer.apple.com/icloud/documentation/data-storage/index.html
https://developer.apple.com/library/ios/documentation/DataManagement/Conceptual/UsingCoreDataWithiCloudPG/BestPractices/BestPractices.html
https://developer.apple.com/icloud/

My IOS App has been rejected- Data Storage Guidelines (2.23) I have 2 possible suspects

my app has been rejected due to iCloud Storage Restrictions. (2.23).
There are lots of questions for this situation, but i am still not sure why my app has been rejected.. Here are my suspects:
1- My app downloads pdf files and images for letting users see on "offline" mode when a user selects a row from a tableview. I've set my download folder as "Documents/privateDownloads" and set the folder (and files inside) url flags as "do not backup"
2- My app also has a 2Mb. "preload.json" file, which my app reads the file at first launch and preloads into the database only at first launch (with a progress hud showing the progress of importing data). I haven't set the "preload.json" file as "do not backup".I just drag dropped the file into "Supporting Files" group in Xcode.
My guess is the problem lies in the 2nd suspect, but i've also read that i should move the "privateDownloads" folder into "Application Support" Folder instead of Documents folder.
i always stored my offline files on nsurl cache for a very long time (technically forever), but this time i've decided to do like this.
thanks for reading and helping.
Edit: there is a note from app store for rejection reason:
"In particular, we found that on launch and/or content download, your
app stores 3.6MB"
When i control this issue, this is happening after my application "preloads" the data. But what i really don't get it is, i am storing this preloaded data in core data. So yes, i want this data to be backed up in iCloud?!
To solve the issue of your seed data being too large, you might split your Core Data stack in two separate stores - one which stores the user data and is backed up to iCloud. And a second one which stores the seeded data imported from your JSON. This store could then be excluded from iCloud backup via the "do not backup"-flags.
Another recommended way would be to ship a pre-populated store like described in this article on objc.io. Since you mentioned your preload.json is several MB, this would be even more desirable to pre-generate the store once than on every device on initial app startup. And you could apply the required file attributes for not backing it up more easily.
The issue won't have anything to do with your preload.json file. If that's included in your app distribution, it is part of the app and you don't need to do anything different with it.
I would suspect that the reviewer didn't notice you were setting the 'do not backup' flag on files you've added to the Documents/privateDownloads folder, or that you have a bug and the flag isn't being set at all. It is safer, if you're able, to store those kinds of files in a /Library/Caches sub directory. Then you don't need to worry about the flag.

Where to copy a readonly data file from bundle?

I'm a bit confused. I'm including in the bundle a Core Data file that will not be modified by the user. Apple rejected my app after I started copying the file to /Documents (due to the new iCloud requirements), so I now I copy the file over to /Library/myprivatedir/
The question is why do I need to copy over to /Library in the first place. What's wrong with it staying in the Bundle after all?
There's nothing wrong with opening a CoreData store from within the bundle. Just be sure to pass the NSReadOnlyPersistentStoreOption as part of the options to -addPersistentStoreWithType:configuration:URL:options:error:
Skimming the docs for iOS Data Storage Guidelines (apple id required) I found this
... Data that can be downloaded again or regenerated should be stored in the <Application_Home>/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.
Because it is easily regenerated they may have taken issue with it.
A couple of points down may be useful if you did have a read/write database scenario
... Use the "do not back up" attribute for specifying files that should remain on device, even in low storage situations. Use this attribute with data that can be recreated but needs to persist even in low storage situations for proper functioning of your app or because customers expect it to be available during offline use. This attribute works on marked files regardless of what directory they are in, including the Documents directory. These files will not be purged and will not be included in the user's iCloud or iTunes backup. Because these files do use on-device storage space, your app is responsible for monitoring and purging these files periodically.

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