How to react to Excel events in Ruby?

I can find 10^1000 examples of scripting Excel using Ruby, but I can't for the life of me figure out how to have Ruby react to events in Excel. I'm trying retrieve the contents of a row in a worksheet when it's selected, but such an event-based retrieval I can't find any methods or examples for.

From stackoverflow

• Use the *WIN32OLE_EVENT.new* method to create an OLE Event object, then call its *on_event* method. Call the *WIN32OLE_EVENT.message_loop* method to launch the event-monitoring loop.

  Here's an example that prints out the selected range's value, then halts event monitoring before the workbook is saved:

  require 'win32ole'
  
  def exit_event_loop
      $LOOP = false
  end
  
  xl = WIN32OLE.connect('Excel.Application')
  wb = xl.ActiveWorkbook
  
  ev = WIN32OLE_EVENT.new(wb, 'WorkbookEvents')
  ev.on_event('SheetSelectionChange') do
      range = xl.Selection
      puts(range.Value)
      STDOUT.flush
  end
  
  ev.on_event('BeforeSave') do
      exit_event_loop
  end
  
  $LOOP = true
  while $LOOP
      WIN32OLE_EVENT.message_loop
      sleep 0.1
  end
  

  Hope that helps.