What is the security model of iCloud Drive on iOS? If I open a file using the file picker in an app, can the app now see all files in that folder?
Is there any other way in which an app might see all the files in my iCloud Drive?
UIDocumentPickerViewController provides apps with open or import access to one or more user-specified files. Folders are not provided to apps for their own access to, and multiple selections must be user-initiated. When an app saves a file, it can retain access to that file but is not granted general access to the containing folder. Apps have access to their own app folders in iCloud Drive, but not the ability for any folder or all files.