CODE EXAMPLE FOR JAVASCRIPT

limit values that satisy a url parameter react-router

   {/* It's possible to use regular expressions to control what param values should be matched.
     * "/order/asc"  - matched
     * "/order/desc" - matched
     * "/order/foo"  - not matched*/}
   <Route
     path="/order/:direction(asc|desc)"
     component={ComponentWithRegex}
   />