09-05-2018 08:03 AM
I've reported this to support, but it's probably worth other users knowing, because of the security and space implications. Investigation of the iXpand directory on a jailbroken iPad shows that the tmp directory retains a copy – in fact appears to retain two copies – of every file copied between the device and the iXpand. These copies persist across version updates, and the manual Clear Cache function doesn't delete them. This appears to be the case for all iXpand models and all iOS devices and system versions, and today's update to the iXpand app (5.0.4) hasn't fixed it.
Obviously this has fairly significant consequences for security (copies of all your deleted files remain in onboard memory) and storage (since your device memory is being filled up with multiple copies of the precisely the files you're offloading to the iXpand in an effort to save space). The persistence of cached copies between app updates also turns out to have been the cause of a longstanding problem with battery drain and device overheating I reported in another thread. You can still get rid of the cached copies by deleting and reinstalling the app, but it's a bit of a chore to have to do this every time you move something confidential off your device; with luck it'll be sorted in an update, but it seems worth alerting users to the issue.
09-05-2018 09:46 AM
The clear cache option only clears thumbnails and the indexing database. This is expected behavior.
How exactly are you copying the files?
When you copy files that are formats other than iOS nativity supported photos and videos the file is stored with in the documents folder and is accessible via the iXpand drive application. These files are not cleared when using clear cache.
When a file is restored from the iXpand to the camera roll the file is copied to the internal memory of the iSO device and then moved to the camera roll. During this process the internal memory space may not be immediately cleared however the memory should be released and the files should clear after a short period of time.
09-05-2018 04:40 PM - edited 09-05-2018 04:43 PM
Thanks for the clarification! I'm not using the camera roll; I'm dealing with an assortment of document, audio, and video files, ranging from regular PDFs and Word documents to app-specific niche formats, using Open In… in both directions (in other words, I'm not using the iXpand app's Documents folder on the iOS device). This seems to deposit one or two intermediate copies, each in its own sub-folder, in the tmp folder at the top level of the iXpand Drive app folder on the iPad; these copies are then not deleted after copying to or from the iXpand drive, even after a period of weeks, and every file copied leaves at least one and usually two copies behind in the tmp directory. I assumed Clear Cache was meant to delete them and simply wasn't working, but it sounds as if there's no way to delete them without deleting and reinstalling the app.
10-08-2019 02:21 PM
updates also turns out to have been the cause of a longstanding problem with battery drain and device overheating I reported in another thread. You can still get rid of the cached copies by deleting and reinstalling the app, but it's a bit of a chore to have to do this every time you move something confidential off your device; with luck it'll be sorted in an update, but it seems worth alerting users to the issue.