I am writing an iOS app which download images from a backend server, and store them in the document directory. I know how it is done.
But I need to write a prototype first, which use some pre-given images (not retrieve from the backend server). My question is, is it possible to store images in the document directory during initial installation of the app? I don't want to hardcode them in the bundle directory.
Thanks
Nothing can be done when the app is installed, only when the app is run. The first time the app runs, you can either copy pre-bundled images to the other directory (Documents) or you can download them as needed. It sounds like you want the first option for the prototype.
Basically you need to do what you don't want to do - hardcode them in the bundle.
Remember, the app's sandbox is setup when the app is installed. This includes the creation of the Documents directory. But nothing is put there. Only your running app can store something somewhere in the app's sandbox.
Related
Bit of a newbie when it comes to this so apologies if i'm using any of the wrong terms!
Whenever I build my application through cordova it assigns it a new application id like
2A7DA53D-C2B8-4804-9800-E664F6F93F23
My application is then storing images in the following directory
"file:///var/mobile/Containers/Data/Application/2A7DA53D-C2B8-4804-9800-E664F6F93F23/Documents/reportimages_7/1535710208164.jpg"
Which works fine, but then once my application is updated, It tries to access images with a previous application id. For example, after updating the app and storing another image it stores in
"file:///var/mobile/Containers/Data/Application/946CCCED-A1B3-4950-9C63-EFD040542115/Documents/reportimages_8/1535710897382.jpg"
I then use cordova file transfer to search for the above urls, and only the images in current application id folder of 946CCCED-A1B3-4950-9C63-EFD040542115 can be found!
Is there any way to skip the application id and just get the files straight from the '/Documents/' so instead it looks for
/Documents/reportimages_7/1535710208164.jpg
/Documents/reportimages_8/1535710897382.jpg
So it can always find the images even after the application ID has changed, or is there any way to always find the images with a changing application id?
Briefly speaking,
"2A7DA53D-C2B8-4804-9800-E664F6F93F23" folder is your Application's sandbox. Applications can access files only in their own sandbox (you would not want other apps to spy on your files, right?)
If you just update (override) your application, your Sandbox folder should not change. If you delete the app before installing new version, or change things like Bundle Identifier in the project, it will create new Sandbox.
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.
Having only worked with Android/web dev before I am having a hard time figuring out where in the world my file should be getting copied to in iOS. After reading the file browser documentation on the iOS developer resource page it says that each app is an "island" which contains its own folder system. If I want to have my user be able to copy a file from my app's sdk to their iOS device, where should I put it?
I downloaded a file browser app from the app store on my iOS testing device but am I right in thinking that there is no global file browsing system?
I am using a Cordova plugin called Asset2sd which works perfectly for me in Android, getting the root storage folder and downloading the file to there. It has no iOS alternative so I'm going to have to figure something else out, I just need to know where to start. Do I have to have the user access my app's internal files somehow? Can I create a folder for them to look in when they download my app? Some documentation or something would be wonderful. I am totally lost.
Thanks!
You're right. Apps don't have access to the global file system. Each app only has access to their own app directory. Here's in-depth information on Sandboxing: https://developer.apple.com/app-sandboxing/
In your app's sandbox, you basically can manage files as you want, i.e. download, copy, move, delete, etc. So you can create a folder Downloads in your apps documents directory and then display the contents of this folder for instance in a table view.
Related documentation/links:
https://developer.apple.com/library/prerelease/ios/documentation/Cocoa/Reference/Foundation/Classes/NSFileManager_Class/index.html
https://stackoverflow.com/a/6907432/967327
https://developer.apple.com/library/ios/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/iPhoneAppProgrammingGuide.pdf
I've been debugging a problem where my app successfully downloads a file and copies it to the Documents directory. Lately the app cannot open the downloaded file on subsequent launches of the app. I've been printing out file URLs and this is what I see when the file is initially downloaded and opened:
unzipped /var/mobile/Containers/Data/Application/9AC69C00-228E-482F-99D8-DD8F214FCE88/Documents/3.atcase to
/var/mobile/Containers/Data/Application/9AC69C00-228E-482F-99D8-DD8F214FCE88/Library/Application Support/thebundleID/current-case
You can see the UUIDs are the same, but when I launch the app again I see this:
couldn't unzip /var/mobile/Containers/Data/Application/9AC69C00-228E-482F-99D8-DD8F214FCE88/Documents/3.atcase to
/var/mobile/Containers/Data/Application/C18E7EFA-C0D0-4213-AF85-F5BC0D2A4207/Library/Application Support/thebundleID/current-case
This time the UUIDs appear to be different.
I will say tentatively that the answer is yes, the UUID used in the application container folder does seem to change every time the app is run, though I'd love to have some confirmation from a more experienced developer.
The solution to my problem was straightforward: Do not store absolute file URLs in the database. The URLs for the files are now constructed relative to the Documents directory URL every time the app is run. Since I name the files in a regular way, there is no need to store URLs anyway.
I have an app that is going to display a list of local video files. The app will only have a couple of video files at first, but that number will grow with future updates and in-app purchases. I would like to store all these videos in 1 place and it makes sense to put them in the app's Library directory so they are not user-accessible. Is it possible to publish an app with files already in the app's Library directory? Or do I have to put them in the app's bundle and then copy them to the Library directory when the app is first launched? Although that would result in the 2 videos files being duplicated since I can't remove them from the bundle.
Yes, you do need to copy the files from the app bundle into the Library if you want to treat all the videos in the same way. You cannot change the contents of the app bundle from inside your app and the only files your app has when it first launches are those that are in the app bundle.
If you really wanted (and if the video files don't change), you could make special cases in your code to be able to get the starting videos from the app bundle and the in-app purchase downloaded videos from the Library directory. But, unless the video files are quite large this seems a bit excessive.
A third option would be to have the user download the starter files on first app launch, but that may be suboptimal for other reasons.
Please look at my answer in this thread. It might concern you or at least be interesting to read.
Does updating iOS apps delete library directory files?