dream/example/w-query

w-query

This very simple example accesses a value in the query string with Dream.query:

let () =
  Dream.run (fun request ->
    match Dream.query "echo" request with
    | None ->
      Dream.respond "Use ?echo=foo to give a message to echo!"
    | Some message ->
      Dream.respond (Dream.html_escape message))

$ dune exec --root . ./query.exe

Visit http://localhost:8080?echo=foo and you will see foo printed! Since we are inserting untrusted client-sent data into an HTML response, we have to escape it with Dream.html_escape. See Security in example 7-template for a discussion. Perhaps you can even launch an XSS attack against an unsafe version of this example!

Up to the example index