We're building an iPad photo gallery with hundreds of images (almost 300mb in size). Having a web app will be a disadvantage because users will have to download the images every time (since Safari on ipad won't cache them I'm guessing?)
So if we built a native ios app instead, would it be possible to download newer images from the web and add it to the app in the future?
Thanks a ton for your help !
Each iPhone application has its own home directory containing Library and Documents folders, and a tmp directory for storing temporary files.
Take a look at section title: A Few Important Application Directories on The Application Runtime Environment.
I would save the your images to Application Home/Library/Caches folder.
Excerpt from Apple Docs:
Use this directory to write any application-specific support files that you want to persist between launches of the application or during application updates. Your application is generally responsible for adding and removing these files. It should also be able to re-create these files as needed because iTunes removes them during a full restoration of the device.
In iOS 2.2 and later, the contents of this directory are not backed up by iTunes.
http://iosdevelopertips.com/data-file-management/save-uiimage-object-as-a-png-or-jpeg-file.html
you could download it on first view, display at the uiimage, then save it off as above
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 just installed iOS 11 beta and I noticed that Offload App, By offloading app what will be remove Shared Directory or User Default or remove both or other than this ?
Looking for suggestions.
Thanks
Offloading lets you ”offload” the bundle (.ipa) for your app to save disk space. It will delete the ipa file (which contains your libraries and resources) and store only Documents and Data that includes shared data, UserDefaults etc..
Once we offload the app, what remains is the app icon of it with a small download pip on it to indicate that it has been offloaded .
Just by simple tapping on it, the app will get downloaded from the store and the saved Documents and Data will be integrated to the downloaded app, instead of an empty directory as it normally would with a fresh install.
This is a really great feature by Apple especially for devices with just 16GB storage. As you can see offloading the Prisma app saves me 44MB which is great. And even more, iOS can automatically offloads unused apps for us.
There is no official document(technical) available for offloading apps till the date but as the description(in setting app) says that your documents and data will be saved then I think it will save user defaults , document directories and core data - I mean all kind of data that can be stored!
It will save Shared Directory & User Defaults. Everything else will be deleted.
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 need to store permanently (as far as app is not uninstalled from the device), the photos that are taken from camera roll and photo library into my app's bundle. Perviously i was storing those file in tmp folder, i read that the contents of tmp folder will be purged by iOS if it finds less memory for other app to run.. so my images were not getting displayed in my app after 3 or 4 days as IOS would have purged the content of tmp folder.
SO where do i need to Store these files? In Documents folder? is documents folder is permanent ?people say that you should not store huge amount of files in documents folder.. There is no limit for the photos that can be taken from my app. user may take 100 photos, 200photos, 500photos, or more than that.. its ok if user uninstall the application.. i will download all those photos in background once he login again. so what would you suggest for this problem? any kind of help is highly appreciated.
thanks
You put the files in the Documents folder, or if you can download them again from Internet, in the cache folder. If in Documents folder, you must mark the files with the attribute that prevents them from getting backed up to iCloud, or your app will be rejected.
Do that using this documentation:
https://developer.apple.com/library/ios/qa/qa1719/_index.html
These rules are enforced pretty vigorously by Apple and spelled out in:
https://developer.apple.com/icloud/documentation/data-storage/
(Requires iOS app developer login to view, I believe.)
What you are looking for here is SQLite. Using SQLite you can store your data and Images.
For storing the Images you can refer this link
I was under the impression that iCloud only worked with UIDocument files.
How about other types?
Also if my user's files get uploaded into the cloud, can he use those files with all his devices if my app is universal?
According to Apple's File System Programming Guide,
Handle support files—files your application downloads or generates and
can recreate as needed—in one of two ways:
In iOS 5.0 and earlier, put support files in the
/Library/Caches directory to prevent them from
being backed up
In iOS 5.0.1 and later, put support files in the
/Library/Application Support directory and apply
the com.apple.MobileBackup extended attribute to them. This
attribute prevents the files from being backed up to iTunes or
iCloud. If you have a large number of support files, you may store
them in a custom subdirectory and apply the extended attribute to
just the directory.
iCloud does back up of the things under Library also.
Ans YES of course if user's files get uploaded into the cloud, then he can use those files with all his devices if the app is universal as iCloud is intended to be the invisible magic that glues your iPhone, iPad and Mac (if you use one) together.