Re: Operate upon POST request with Guile webserver

[Gentoo Arch <gentoocore@firemail.cc>]

Hi Ricardo,

Thank you, that really looks like a prototype for MVC app I wanted to craft.

On 8/21/22 22:47, Ricardo Wurmus wrote:
> Hi,
>
> Gentoo Arch <gentoocore@firemail.cc> writes:
>
>> I'm trying to figure out how Guile webserver works to develop a simple
>> BBS  and I'm kinda stuck with POST request.
>>
>> My Guile script generates a form on any path and the form sends to
>> "/post" path, where I can easily render content sent by the form.
> Daniel already solved your immediate problem, but I wanted to show you a
> common pattern many of us use to build web servers:
>
> --8<---------------cut here---------------start------------->8---
> (define* (render-html sxml #:optional (headers '()))
>    (list (append '((content-type . (text/html))) headers)
>          (lambda (port)
>            (sxml->xml sxml port))))
>
> (define (request-path-components request)
>    (split-and-decode-uri-path (uri-path (request-uri request))))
>
> (define (controller request body)
>    (match (cons (request-method request)
>                 (request-path-components request))
>      (('POST "api" "container" id "launch")
>       (render-html `(html
>                      (head (title "whatever"))
>                      (body "who cares"))))
>      (('PUT "api" "container" id "connect")
>       ...)
>      (('DELETE "api" "container" id)
>       ...)
>      (('GET "api" "containers")
>       ...)
>      (('GET "api" "container" id "info")
>       ...)
>      (_ (not-found (request-uri request)))))
>
> (define (handler request body)
>    (format (current-error-port)
>            "~a ~a~%"
>            (request-method request)
>            (uri-path (request-uri request)))
>    (if (getenv "DEBUG")
>        (call-with-error-handling
>          (lambda ()
>            (apply values (controller request body))))
>        (apply values (controller request body))))
>
> (define (run-my-server port)
>    (run-server handler #:port port))
> --8<---------------cut here---------------end--------------->8---
>
> The controller uses match on the method and the path, which makes for
> pretty clear code.  You can bind parts of the path to variables and
> operate on them.
>
> The “values” stuff is handled in “handler” here, but it also be done
> directly in the controller.
>
> To operate on the POST payload, you’d need to parse the form data from
> the body, which is available to the controller.  See also guile-webutils
> for some handy tools.
>
> Hope this helps!
>