Oddest issue, thought I would see if anyone had run into this before.
We have an iPad application that stores PDF files in the documents directory. All goes great, we can open the PDF's with CGPDFDocumentCreateWithURL all day long. Then, we reinstall the application from the same adhoc site, and for some reason are not able to load the files. We can iterate the documents folder, see the files there, but can't open them. We just get a nil back from CGPDFDocumentCreateWithURL.
This feels very much like the permissions on the files change after the update, but can't prove that.
So, has anyone encountered this post update? Is there anyway to get a error return from CGPDFDocumentCreateWithURL?
We encountered a similar problem recently and perhaps the same is happening to you.
Are you using the complete URL/path which you had (probably) saved before you updated the application.
The reason is that the App_Home directory changes on updates. So if earlier it was:
/var/mobile/applications/<guid1>/
after the update it will become
/var/mobile/applications/<guid2>/
The solution is to save relative paths from App_Home directory.
Related
I have an electron app, and when I make it, it packages and compiles everything.
Sounds like it works perfectly right?
Well, problem is I want one of the folders to not be compiled, but still be accessible by my static files, so the users can add or remove content from the folders.
I've tried making it in a seperate folder, but then it can't find the files even when it's placed in the correct relative path.
Overall, I want my app to exist next to a folder and my <script src="./folder/script.js"></script> to actually be able to access it.
I'm new to basically anything node or electron so i'm probably making some dumb mistake.
Thanks in advance.
Having your user touching files close to your Electron application may be fraught with danger. If they accidently overwrite an important file or accidently delete an important file then your application may stop working and require the user to perform a re-install.
Instead, have any default files the user may need to "touch" packaged up with your application and then upon your applications first run, copy these files (and any necessary folder structure) over to the users home, desktop, documents, downloads or even userData directory.
That way, your application will always know where to find them and the directory is a directory your user will already be comfortable adding files to and removing files from.
You can always let the use choose where these files are stored as a settings option which persists in an application setting file, using something similar to path.join(app.getPath('userData'), 'settings.json');
See Electron's app.getPath(name) for more information.
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 have a SQlite database file with records which comes with my app.
I just used the file I added to my project to make my INSERT and UPDATE statements.
After uploading it to my test device I got the exception that the file is read only.
After a bit of research I found out, that I have to copy the db file to the users directory to make an insert. This works for now. But I have a view questions about it, which i didn't get answered through google:
Where should I put my copy process?
I implemented it in the AppDelegates FinishedLaunching, where I check if it already exists.
Where should I copy the file to?
I used the MyDocuments folder for now, is this ok?
Since the file cannot be encrypted, can another app access the database file?
When the user decides to delete the app from the device. Will the database file get deleted,too?
Thanks!
Where should I put my copy process? I implemented it in the AppDelegates FinishedLaunching, where I check if it already exists.
That really depends, but finishedLaunching is OK from my point of view.
Where should I copy the file to? I used the MyDocuments folder for now, is this ok?
I'm not sure what you mean by "MyDocuments" folder. Each Application has a dedicated Document directory. That's where you should copy it.
Since the file cannot be encrypted, can another app access the database file?
No, they run sand-boxed (unless the device is jailbroken)
When the user decides to delete the app from the device. Will the database file get deleted,too?
Yes, since the whole document directory will be deleted.
Where should I put my copy process? I implemented it in the AppDelegates FinishedLaunching
Keep in mind that you have a limited amount of time to complete FinishedLaunching execution (around 15 seconds) before the iOS watchdog kills your application.
Depending on the size of your database, the speed of device and other processing you need to do then you might want to consider only checking if it already exists (that should be quick) then do the copy (if required) from to another thread.
I used the MyDocuments folder for now, is this ok?
Yes, using Environment.GetFolderPath (Environment.SpecialFolder.MyDocuments) is correct.
Everything else from #Lightforce answer covers the rest.
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?)
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.