title: RoR sort/scope/filter via button
body: <p>I came across this site:</p>
  
  <p><a href="https://tutorials.railsapps.org/rails-tutorial" rel="nofollow">https://tutorials.railsapps.org/rails-tutorial</a></p>
  
  <p>And was wondering if someone could explain how the buttons would be set up to filter?</p>
  
  <p>I guess I'm curious also - is an object being displayed and filtered? What is going on here?</p>