dream

Now we serve a tiny site dynamic site. If you go to http://localhost:8080/echo/foo, it responds with foo. If you change the last path component to bar, it will respond with bar instead:

let () =
  Dream.run
  @@ Dream.logger
  @@ Dream.router [

    Dream.get "/"
      (fun _ ->
        Dream.respond "Good morning, world!");

    Dream.get "/echo/:word"
      (fun request ->
        request
        |> Dream.crumb "word"
        |> Dream.respond);
  ]
  @@ fun _ ->
    Dream.respond ~status:`Not_found ""

As you can see, if the router sees a path component that begins with :, it becomes a variable, which can be accessed in the handler by calling Dream.crumb. This example also uses |>, the standard OCaml operator for piping a value into the last argument of a function.

We are now also resonding to /favicon.ico and all other requests with 404 Not Found, which causes most browsers to stop requesting it after the first attempt.

Where to go from here?

5-catch handles errors from all your handlers in one place.