I'm having a problem for my app, a Chinese-English dictionary. I'm now adding a wordbook for it, and try to save the contents of it to a plist every time users exit the app. But now I find that as my app updates, all these data will get lost because the path of the app is changed.
I'm now working for a company so the app will keep releasing new versions, and how can I save the data from version to version?
all these data will get lost because the path of the app is changed.
That would indicate you're writing to your application's directory structure. Don't do that.
The iPhone has a documents directory.
Document Directory discussion
Related
I have developed a Flutter app that captures images using the camera and I store references to the image files using Shared Preferences.
When I upgrade the iOS app, the Shared Preference filename persists as expected, but the image no longer displays on the iOS device (and no longer seems to exist) File(_imageFileRef).existsSync() is false
For example, on iPhone, the image file is saved as
/private/var/mobile/Containers/Data/Application/580A9879-23CD-413D-A785-DB910673DF74/tmp/some_guid_image_name.jpg
When the app is upgraded, this file no longer seems to exist.
Where should I be saving the image files to in iOS so that they persist across upgrades?
The functionality works perfectly on Android devices.
Having received no answers, I delved a bit deeper and discovered that...
...the tmp directory in which the images are being written is for temporary files that do not need to persist between launches of your app. Your app should remove files from this directory when they are no longer needed; however, the system may purge this directory when your app is not running. The contents of this directory are not backed up by iTunes or iCloud.
So in order for the data to persist over app updates, I need to be writing to the Documents directory
Info obtained from here
I am developing a social application for iOS using Objective-c. But when I published the newer version of my app and upgraded it using App Store, all of my older application data has been removed while every thing in both versions is the same like Bundle Identifier, Provisioning Profile, Signing Certificate. But I am confused why some thing like that happened. I was wondering if anyone could help me. This is too important for me, because this problem forces users to register again in the application.
update: I save data in the documents and also using core data
It might not be cleared just the path of the files changed, for example lets say you save the path of a photo like this :
/data/Containers/Data/Application/B42FE84A-E031-4A2C-AEA7-8D77AEAA389C/Documents/Photo.jpg
when you update the app the path will look like this because iOS will change app documents folder
/data/Containers/Data/Application/757455E1-355B-4040-8ABB-85F39D650A1E/Documents/Photo.jpg
so the file still exist but the path have changed and since you are saving the path the app won't find it because it was changed
i recommend saving only file name not the whole path
I am new to ios development so please pardon if I am asking a silly question.
I need to check if my sql file from the previous installation of the same app exists in the device directory already. If yes, then I need to fetch that file instead of making the new one. But the bundle folder of the app changes after reinstalling the app. So I cant guess the name of the previously installed app bundle folder. I tried to save it elsewhere on the device, but it isn't allowing me. Please suggest me the solution.
What you're asking for isn't possible. If an app is removed, all its files are deleted as well. In iOS, there is no app-neutral place to store files. When an app is merely updated, the update happens "in place" from the perspective of the app, and all previous files are available.
If you want files to survive a delete-reinstall cycle, you'll have to use a cloud service, such as iCloud, Dropbox or Google Drive.
once app is deleted. Application bundle and document directory and all files (including SQLite file)are deleted. u have to fetch all data from API.
In iOS each application is a Sandbox. This Sandbox consists of Application bundle and Mutable part where you store your database and other files which are mutated during the life span of an application.
When you delete the application, entire Sandbox is removed. The only thing which does not get remove is the data which you have stored in keychain.
When you update the application, only application bundle gets updated and Mutable part remain un-touched. So while re-installing the application when it is already present (technically updating the existing application on the device), you can find the same file from the same location.
You can do one thing you can take daily backup of that file on remote server and when you reinstall app check that file exist on server if exists than download else create new.
I am going to publish a new version of my app on app store. I just want to know that if the app is being updated from the previous version or user has installed a fresh copy of the new version of my app. Based on this information i want to show some information to the updated users.
I was thinking of to keep a key in my NSUserDefaults of the previous_version but i haven't added any such key in the NSUserDefaults of my previous app version. So this key will be nil in both cases in my new version.
Is there a way i can get to know if the user has updated the app or installed a fresh copy of my app.
There is no direct way for it. Indirectly you can check it. If you are moving your editable data into Documents directory in your previous version then at the time of launching new application, you can check if the file is present in document directory. If you can find it, the application is opened after update and if file is not present then it has been opened because of a fresh installation.
My iOS app is intended to be compatible with iOS 5.0 and above, and it has iCloud capabilities turned off in it's target settings, I'm not integrating with iCloud. My app stores an sqlite file and some image files into Documents folder. The sqlite file is not downloadable, but images are.
I've read some posts from people saying that their app's submission was rejected because they don't met the iOS Data Storage Guidelines, but I'm not sure if that is only required if your app has iCloud capabilities enabled, is it? Should I set the NSURLIsExcludedFromBackupKey for my files anyway?
Thanks in advance
EDIT
I've read this here:
It is not possible to exclude data from backups on iOS 5.0. If your app must support iOS 5.0, then you will need to store your app data in Caches to avoid that data being backed up. iOS will delete your files from the Caches directory when necessary, so your app will need to degrade gracefully if it's data files are deleted.
But I need the sqlite file to be in Documents to insert data... how should I handle this?
It has nothing at all to do with whether your app uses iCloud or not. It has to do with the user performing backups to iCloud which is beyond the control of your app.
If all of the data in your app that is stored in the app sandbox is data that is created and stored by the user through the use of the app then Apple will have no problem with the data being backed up.
They have issue with replaceable files being backed up needlessly. If the database file is read-only and could be obtained from a server or the app bundle then don't let it be backed up. But if it starts out mostly empty and then gets data added as the user adds data through the app then it should be backed up. Same for the images.