5.4 More complex URL remapping

Try this code:

(use-modules (artanis artanis))
(init-server)
(get "/hello/:who"
  (lambda (rc)
    (format #f "<p>hello ~a</p> " (params rc "who"))))
(run #:port 8080)

Now you can try http://localhost:8080/hello/artanis in your browser.

There are two differences compared to the simpler example:

• 1. The special rule, "‘/hello/:who’", :who means you can use params to refer to the value of the par of the URL with the key "who". Like: (params rc "who").
• 2. You may have noticed that the handler is being defined as an anonymous function with lambda has one argument rc. It means route context which preserves all the related context information. Many GNU Artanis APIs need it, e.g. params.

And format is a Scheme lib function. It is similar to sprintf in the C language, which outputs text with a formatted pattern. The second argument #f (means FALSE) indicates that the formatted output should be returned in a string rather than printed out.