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
Related
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.
In my iPhone app, I am downloading files from server and storing them locally (user's document directory). The path of each file downloaded is subsequently updated in database.
If user tries to delete a file, first the file is deleted from local path using removeItemAtPath: (NSFileManager), then corresponding record is deleted from database.
Now I have one of the requirements according to which user can turn on a UISwitch to delete all data on app exit.
Now my question is -
suppose user downloaded 20000 files, say small images, and user turned
on the switch to delete all data on app exit. Is it good to handle
this task in applicationWillTerminate? What is the best way to
accomplish this scenario?
Please suggest.
Don't delete the files individually, delete and recreate the folder.
Your database could be handled differently by version tagging so that you can batch delete the items on the next run.
applicationWillTerminate will only be called if your app goes background (the only option by pressing Home button of the device) and "Application does not run in background" key is set in your app's info.plist file to "YES". Otherwise it won't ever be called.
If you are planning deploy app with similar functionality, you can use applicationWillTerminate for removing so many files. However, I would never recommend you that. Instead, my recommendation is to remove the files as soon as they are processed, if possible at all.
Another thing you must consider is not to save so many files in Document directory, however small those are. Document directory is backed up by iTunes and iCloud and if you store so many files there, you are gonna possibly violate Apple's Data Storage Guideline that would reject your app from App Store. It is always a good idea to store transient files in application's "tmp" directory and delete them when not required anymore.
I developed an Ipad app which download different kind of files, but after a week or some days the downloaded files are removed and the app that open the file can find it anymore.
Could anybody help me, Where should I save downloaded files in my app to avoid that the file came automatically deleted?. IOS usually remove downloaded files after certain time?.
I already read this apple documentation
I know that maybe is not something complicated but I can't figure out why the file is removed If anybody can help me I'll appreciate that.
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.
Most probably you are using caches/temp directory which the system can clear contents of in case of low space. To avoid deletion use Documents Directory.
If you are already storing in documents directory, then the file can appear missing if you are storing its hardcoded path , which can change during app update. Try storing relative path and log the contents of your documents directory to see what files exist.
save the files in your local sqlite db, data core or if you can serialize them with the standard user defaults
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.
I need to store some data files for my blackberry app. These are usually small png files that I download and store locally for performance reasons. Also I need to store an xml file locally.
My question is where are these files supposed to be saved on a blackberry? Is there such a thing as an application's home folder or settings folder in the blackberry filesystem?
What would be the path to such a folder?
This is for blackberry os 4.7 or later.
Thanks!
If it's not a huge amount of data (and by the sounds of it, it's not), take a look at the PersistentStore mechanism. You can store many types of data including native types (String, Integer, etc.) and even byte[] data (for images) using PersistentContent. The nice thing about PersistentStore is that it doesn't require any sort of filesystem access -- it doesn't leave files hanging around -- and if you include a custom class in the persistent store for your app (even a simple subclass of an existing persistible class such as Hashtable), it will automatically delete your persisted data if the app is deleted.
There's no official home folder for your application. In blackberry you can basically read/write just about anything/anywhere (well, you might get a SecurityException/IOException if you'll try do change some files).
You can write to the SDCard/Internal memory using the paths described here.
If you're worried about someone seeing and altering your data there's not much you can do except setting your files and directories as hidden using FileConnection.setHidden(true) but this is very lame since they can still be seen even from the native BlackBerry file browser if the user chooses to show hidden files from the menu.
Edit: You could of course encrypt/decrypt your data but this won't prevent someone from deleting it.