Open e-mail attachment with Ionic app on iOS

I would like the following sequence of events to be possible:

  • User receives e-mail with file attached (.cup extension)
  • Opens e-mail in e-mail client app
  • Selects .cup file attachment, ‘open with…’ dialog opens, Ionic app selected
  • Ionic app opens and contents of file are manipulated/displayed

Is there some way of achieving the third step on Ionic for iOS? This is somewhat achievable on (Ionic for) Android (as detailed on this stackoverflow post) as well as on native iOS using info.plist (detailed on this blog post), but I haven’t found a solution for achieving this through Ionic for iOS. Is this possible, or am I misunderstanding how iOS allows transmission of data between applications?