I really hope you can help me with this. I have an app that uses the excel module. The excel sheet is stored locally. However, because the information is sensitive, I would like to remove that feature and instead fetch the spreadsheet from an ftp server and cache it when the app is opened and flush it out when it's closed.
As you've already got your App working with a local copy of the file have you considered encrypting the file instead? It might be a simpler change to make. I've not used the encryption library but it's an option.
However you will still need to save the file and there is always a chance that process will crash or that the device will be turned off before you are able to delete it.