racket/collects/web-server/lang/web.ss
Jay McCarthy aed865f2b0 Updating docs and timer.ss
svn: r6492
2007-06-06 00:26:12 +00:00

91 lines
3.2 KiB
Scheme

(module web mzscheme
(require (lib "serialize.ss")
(lib "plt-match.ss")
(lib "url.ss" "net")
"../private/request-structs.ss"
"abort-resume.ss"
"../private/session.ss"
"stuff-url.ss"
"../private/url-param.ss")
(provide
;; Server Interface
initialize-servlet
;; Servlet Interface
send/suspend/hidden
send/suspend/url
extract-proc/url
embed-proc/url)
;; initial-servlet : (request -> response) -> (request -> response?)
(define (initialize-servlet start)
(let ([params (current-parameterization)])
(lambda (req0)
(call-with-parameterization
params
(lambda ()
(dispatch
(lambda (req1)
(or (request->continuation req1)
; Try to decode a continuation from the request,
; or, use the start procedure to initialize a session
(lambda (req2) (dispatch-start start req2))))
req0))))))
;; send/suspend/hidden: (url input-field -> response) -> request
;; like send/suspend except the continuation is encoded in a hidden field
;; XXX incorporate stuffing in some way
(define (send/suspend/hidden page-maker)
(send/suspend
(lambda (k)
(let ([p-cont (serialize k)])
(page-maker
(session-url (current-session))
`(input ([type "hidden"] [name "kont"] [value ,(format "~s" p-cont)])))))))
;; send/suspend/url: (url -> response) -> request
;; like send/suspend except the continuation is encoded in the url
(define (send/suspend/url page-maker)
(send/suspend
(lambda (k)
(page-maker
(stuff-url k
(session-url (current-session)))))))
; XXX Don't use stuff-url, but use the other serialize thing
(define embed-label "superkont")
(define (embed-proc/url k-url proc)
(define superkont-url
(stuff-url proc
(session-url (current-session))))
(define result-uri
(insert-param k-url embed-label
(url->string superkont-url)))
(begin0 result-uri
(when (> (string-length (url->string result-uri))
1024)
(error "the url is too big: " (url->string result-uri)))))
(define (extract-proc/url request)
(define req-url (request-uri request))
(define maybe-embedding (extract-param req-url embed-label))
(if maybe-embedding
(let ([proc (unstuff-url
(string->url maybe-embedding))])
(proc request))
(error 'send/suspend/dispatch "No ~a: ~S!" embed-label)))
;; request->continuation: req -> continuation
;; decode the continuation from the hidden field of a request
(define (request->continuation req)
(or
; Look in url for c=<k>
(let ([req-url (request-uri req)])
(and (stuffed-url? req-url)
(unstuff-url
req-url)))
; Look in query for kont=<k>
(match (bindings-assq #"kont" (request-bindings/raw req))
[(struct binding:form (id kont))
(deserialize (read (open-input-bytes kont)))]
[_ #f]))))