code: def on_complete(cls, req):
          
          # handle http errors
          if not (req.status == 200 or req.status == 0):
              alert("Couldn't connect to authority base.")
              LogView.add(
                  "Error when calling Aleph authority base: %s" % req.text
              )
              AuthorBar.hide()
              return
  
          AuthorBar.hide()
          cls.set_select(json.loads(req.text))
docs: Callback called when the request was received.