* use Oleg's SSAX (SSAX->HTML et al.)

* add continuation counter in servlet-handler, thus the generated continuation
  urls are a bit more human readable.

scheme/httpd/surflets/packages.scm

@@ -1,4 +1,7 @@
 ;; Structures and interfaces for servlets.
+;; NOTE: SSAX/lib/packages.scm must be loaded before you can use this
+;; downloadable from http://sourceforge.net/project/showfiles.php?group_id=30687
+;; (take the r5rs compliant version (ssax-sr5rs-plt200-4.9.tar.gz))
 
 (define-interface rt-module-language-interface 
   (export ((lambda-interface 
@@ -84,14 +87,15 @@
 	profiling			;PROFILE-SPACE
 	httpd-logging			;HTTP-SYSLOG
 	shift-reset			;SHIFT and RESET
+	sxml-to-html			;SXML->HTML
 	scsh				;regexp et al.
 	scheme
 	)
   (files servlet-handler))
 
 (define-interface plugin-utilities-interface
-  (export send/suspend
-	  send/finish
+  (export send-html/suspend
+	  send-html/finish
 	  ))
 
 (define-interface plugin-interface

scheme/httpd/surflets/surflet-handler.scm

@@ -4,12 +4,14 @@
 
 ;;; instance-table: entry for every new request on a servlet page
 (define-record-type instance :instance
-  (make-instance servlet-name continuation-table)
+  (make-instance servlet-name continuation-table continuation-counter)
   instance?
   (servlet-name really-instance-servlet-name
 		set-instance-servlet-name!)
   (continuation-table really-instance-continuation-table 
-		      set-instance-continuation-table!))
+		      set-instance-continuation-table!)
+  (continuation-counter really-instance-continuation-counter
+			set-instance-continuation-counter!))
 
 (define-record-type session :session
   (really-make-session instance-id return-continuation)
@@ -95,26 +97,45 @@ You can try starting at the <A HREF=~a>beginning</a>."
 		   (resume req)))))))))))
   
 	
-(define (send/suspend response-maker)
+(define (send-html/suspend html-tree-maker)
   (shift return
 	 (let* ((instance-id (session-instance-id))
 		(continuations-table (instance-continuation-table instance-id))
+		(continuation-counter (instance-next-continuation-counter instance-id))
 		(continuation-id (generate-new-continuation-id instance-id)))
 	   (table-set! continuations-table continuation-id return)
 	   (let ((new-url (make-resume-url (instance-servlet-name instance-id)
 					   instance-id 
+					   continuation-counter
 					   continuation-id)))
-	     (response-maker new-url)))))
+	     (make-usual-html-response
+	      (lambda (out options)
+		(with-current-output-port*
+		 out
+		 (lambda () (SXML->HTML (html-tree-maker new-url))))))))))
 
-(define (send/finish response)
+(define (send-html/finish html-tree)
   (instance-delete (session-instance-id))
-  response)
+  (make-usual-html-response
+   (lambda (out options)
+     (with-current-output-port*		; don't want to blame Oleg, but...
+      out
+      (lambda ()  (SXML->HTML html-tree))))))
+
+(define (make-usual-html-response writer-proc)
+  (make-response
+   http-status/ok
+   (status-code->text http-status/ok)
+   (time)
+   "text/html"
+   '()
+   (make-writer-body writer-proc)))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; access to instance-table
 (define (save-instance! servlet-name instance-id)
   (table-set! *instance-table* instance-id
-	      (make-instance servlet-name (make-integer-table))))
+	      (make-instance servlet-name (make-integer-table) 0)))
 ;; FIXME: make continuation-table thread-safe
 
 (define (instance instance-id)
@@ -126,6 +147,16 @@ You can try starting at the <A HREF=~a>beginning</a>."
 (define (instance-continuation-table instance-id)
   (really-instance-continuation-table (instance instance-id)))
 
+(define (instance-continuation-counter instance-id)
+  (really-instance-continuation-counter (instance instance-id)))
+
+(define (instance-next-continuation-counter instance-id)
+  (let ((instance (instance instance-id)))
+    (set-instance-continuation-counter!
+     instance
+     (+ 1 (really-instance-continuation-counter instance)))
+    (really-instance-continuation-counter instance)))
+
 (define (instance-delete instance-id)
   (table-set! *instance-table* instance-id #f))
 
@@ -133,8 +164,7 @@ You can try starting at the <A HREF=~a>beginning</a>."
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; ID generation  
 ;; FIXME: make this thread safe
-;; FIXME: this may loop forever, if the table is full
-;;(max. 2**28-1 instances)
+;; FIXME: this may loop forever, if the table is full (can this happen?)
 (define (generate-new-instance-id)
   (let loop ((instance-id (random)))
     (if (instance instance-id)
@@ -143,8 +173,7 @@ You can try starting at the <A HREF=~a>beginning</a>."
 
 
 ;; FIXME make this thread-safe (locks)
-;; FIXME this may loop forever, if the table is full 
-;; (max. 2**28-1 continuations)
+;; FIXME this may loop forever, if the table is full (can this happen?)
 (define (generate-new-continuation-id instance-id)
   (let ((continuation-table (instance-continuation-table instance-id)))
     (let loop ((continuation-id (random)))
@@ -214,12 +243,13 @@ You can try starting at the <A HREF=~a>beginning</a>."
 ;; RESUME-URL
 (define *resume-url-regexp* (rx (submatch (* (- printing ";"))) 
 				";k" (submatch (* digit)) ; Instance-ID
-				";c" (submatch (* digit)))) ; Continuation-ID
+				";c" (+ digit) "-" (submatch (* digit)))) ; Continuation-ID
 
-(define (make-resume-url full-path instance-id continuation-id)
+(define (make-resume-url full-path instance-id continuation-counter continuation-id)
   (string-append full-path
-		 ";k" (number->string instance-id)
-		 ";c" (number->string continuation-id)))
+		 ";k" (number->string (session-instance-id)) 
+		 ";c" (number->string continuation-counter)
+		 "-" (number->string continuation-id)))
 
 (define (resume-url-instance-id id-url)
   (receive (instance-id continuation-id)

web-server/root/surflets/news.scm

@@ -20,34 +20,14 @@
       (if (null? *data*) (read-data))
       (let loop ((count (- (length *data*) 1)))
 	(if (< count 0)
-	    (send/finish 
-	     (make-response
-	      http-status/ok
-	      (status-code->text http-status/ok)
-	      (time)
-	      "text/html"
-	      '()
-	      (make-writer-body
-	       (lambda (out options)
-		 (format out 
-			 "<HTML><BODY><H1>THAT'S IT<H1><P>
-That's it...</BODY></HTML>")))))
+	    (send-html/finish 
+	     `(html (body (p (h1 "THAT'S IT"))
+			  (p ("That's it...")))))
 	    (begin
-	      (send/suspend 
+	      (send-html/suspend 
 	       (lambda (next-url)
-		 (make-response
-		  http-status/ok
-		  (status-code->text http-status/ok)
-		  (time)
-		  "text/html"
-		  '()
-		  (make-writer-body
-		   (lambda (out options)
-		     (format out 
-			     "<HTML><BODY><H1>~a<H1><P>
-<A href=~a>read more...</A></BODY></HTML>"
-			     (list-ref *data* count)
-			     next-url))))))
+		 `(html (body (p (h1 ,(list-ref *data* count))))
+			(a (@ href ,next-url) "read more..."))))
 	      (loop (- count 1))))))
     ))