I have an app that downloads several pdfs and images. It all work perfectly fine, I store information of those files in core data. My problem comes when I send out updates of the app, all the information in core data is transferred to the new version correctly but the files are nowhere to be found.
I guess I can write a routine to run when users update the app and download the files all over again. I just believe there is a better way to go by preserving the files.
Has anybody experience on this?
You could store the files in the Documents dir, there they will be not deleted unless you remove the app from the device.
Related
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
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
My app have too much dynamic app resources like images, html+css and xml or json files..that can be updated, So I cannot put these resources in app bundle it will not get updated once on app store i need to have it updated there...secondly i also cannot put these resources on server where I can request the content from server every time i need it...
So my question is that is good to store data locally in document directory??? how does apple app review team will react to it? I have heard that there is an iCloud problem while putting data in document directory is it right?
So where to store data of iOS application locally on device?
Thanks in Advance.... Looking for some good solid answer!
This kind of data should be copied to ~/Library/Application Support. See the File System Programming Guide for full details on where everything goes and how it will be treated.
You may want to consider having the initial assets you are referring to be resident in your application bundle. And then when you have updated versions, save them in your Documents directory (or any legal path you want).
The reason for this is for failover, in case there is a problem, it allows you to revert back. When you are dynamically loading content, you have to factor in you can encounter various problems during a download such as corrupt data or even a dependency not being downloaded yet.
FWIW, I implemented this for a game that supported dynamic loading of content. The bundle had the original assets. There was a temp download directory. When data was validated, it was moved to a locale where it was consumable. On app start, the first step was to just copy the data from the bundle to the consumable directory. While it seems perhaps wasteful and several steps, it worked surprising well and most would not even know this sort of thing was happening.
What happens when I update an app that has some files stored in the Documents folder? I need those files to be kept in that folder so the updated app will be able to use them. But it doesn't seem to happen. Is there anyway I can manage to save all my files?
Your documents will stay where they are - unless the user deletes the app before updating (but that wouldn't be an update..).
I have a simple app that downloads some data from a webservice and displays it in tableviews. In order to allow offline access, the app caches this data in the cache directory on the device itself. I keep a list of all of the cached files for reference, and save that to the cache directory as well. So after all of the downloads are complete I have the following files:
XMLFileList
XML1
XML2
...
I launched this app a couple weeks ago, and have since had to release a few minor updates as necessary to fix some minor bugs. It seems, however, that when a user updates the app on their device, they no longer see the downloaded resources. I have managed to get this to happen on a development device, by updating through the app store, then loading a debug build, and determined the following problem
It would seem that it is not displaying the data in the downloaded files because they no longer exist. It is also not re-downloading the files because they show up in the saved list. This provides a rather interesting question: why did the cached XML files get deleted, but not the master list?
What exactly is going on behind the scenes during an app update that I could account for, or reproduce to ensure this does not continue happening?
If you're putting files into /Library/Caches (or whatever it is), then there is no guarantee that those files will be there the next time you run your app. Anything you put into /Documents, however, will be there. And in fact, anything in /Documents will also be backed up to iCloud (unless you set the bit newly available in iOS 5.0.1 that lets you opt-out files in /Documents from being backed up.)
Anyway, the point is that you should read Apple's docs on what files you should put where. (I searched around for the correct reference unsuccessfully; I've seen it before though.) It boils down to this: Anything that is user generated should go in /Documents, anything that can be re-fetched from a server should go in /Library/Caches and may be purged by the OS.
Cache directory contents are not guaranteed to be preserved. But I don't see any documented guarantee that the entire directory will be cleared all at once. (Maybe only the biggest and/or oldest contents or some such?)