Impossible to use an external MIDI device as an input in the demo app

[jraoult]

I'm trying to use and external MIDI keyboard but the list of available input devices is not complete. Reading the code (https://github.com/jariseon/webdawplugins/blob/master/runtime/demo.html#L283) I can understand that if there is more than 1 device the first one is put in the correct section (inputs) but the remaining devices are incorrectly put in the outputs section.

You probably want something more along the lines of:

io.forEach( function (it, idx) {
  for (var itport = it.next(); !itport.done; itport = it.next())
    {
      var port = itport.value;
      var option = new Option(port.name);
      option.midiport = port;
      if (idx == 0) midiport_in.appendChild(option);
      else midiport_out.appendChild(option);
    }
});

Then, seems like the onmidiport function is not present but is expected to be executed every time the selection of input / output MIDI device changes. The input device is never actually updated and the virtual keyboard / arpeggiator stays set as the input.