[Chicken-hackers] URL dispatching for http-server

[Mario Domenech Goulart]

Hello,

I'm playing with a code (attached) to allow mapping URLs to Scheme
procedures.  It's supposed to work with http-server (and spiffy).

Example:

An access to

  http://myserver.net/add/1/2

would ask spiffy to execute

  (add "1" "2")

To achieve that, currently I have to do the following:

  ;; register the path from which the URL->procedure mapping should be
  ;; considered.  E.g., this tells http-server that the first "path
  ;; part", counting from the given path (`/'), should be considered a
  ;; procedure name and the remaining "path part" the arguments.
  (register-dispatcher "/")

  ;; define a procedure and add it to a list of procedures which can
  ;; be safely executed from an URL.  Attempts to call procedures not
  ;; defined with `define-callable-url' should fail.
  (define-callable-url (add . args)
     (apply + (map string->number args)))

Now the questions:

1. I had to hack the http-server's `http:find-resource' procedure to
   match regex patterns instead of plain strings.

  (define (http:find-resource url)
    (let loop ((keys (hash-table-keys resource-table)))
      (and-let* (((not (null? keys)))
                 (current-key (car keys)))
            (if (string-match current-key url)
                (hash-table-ref resource-table current-key)
                (loop (cdr keys))))))

  1.1. Is it necessary?  Can http-server do something similar without
    this modification? I need this to match _any_ request from a given
    path.

  1.2. Are there security or backwards compatibility issues regarding
       to this change?

2. Is there a "standard" name for this kind of feature (what I'm
   calling "url-dispatching" -- stolen from Django, which seems to
   implement something similar, as far as I understand)?

3. Comments?


Best wishes,
Mario

url-dispatcher.scm
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