title: Swift - App Extension to open PDF files
body: <p>I want my app to be able to copy PDF files from Safari, <a href="https://i.stack.imgur.com/pFoo3.jpg" rel="nofollow noreferrer">just like adobe reader can copy them from Safari.</a></p>
  
  <p>Is this a private API that adobe reader uses?
  I can't find any guide about such action and by reading apple documentation I became more confused and now I have no idea if I need to use a UIActivityViewController or a UIDocumentInteractionController.</p>