title: How do I monitor a file system event within a Shiny app
body: <p>How can I monitor a change to a file system (or other external event) in real time using a Shiny app? For example, suppose I have a dashboard app that provides statistics on files located on the server. I would like to update my statistics in real time as those files change or new ones are added.</p>
  
  <p>My thought is to use Javascript on the client to regularly poll the server. Every 10 seconds, e.g., I might call <code>Shiny.setInputValue("check.fs", 1, {priority: "event"});</code> and then on the server I'd have <code>observeEvent(input$check.fs, { ... })</code>, which would update reactives.</p>
  
  <p>Any other ideas? Is there any way to do this only on the server without javascript?</p>