AToBToC - Cookbook - s c h e m a t i c s : c o o k b o o k

Web_Programming

Problem

Many of the examples I've seen to date showed how to go from page A to page B to page C, by having C's page's procedure call B's which called A. A's page would display; when A was done, B's page would display; when B's page was done, A would display.

Going from A to B to C to page A (without using the Back button) is a bit trickier.

Solution

Here is a runnable module with three pages, where each page has links to the other two pages.

(module AToBToC mzscheme
  (require (lib "servlet.ss" "web-server")
           (lib "etc.ss"))

  (provide timeout interface-version start)
  (define timeout 1500)
  (define interface-version 'v1)


  (define callback-a
    (lambda (request)
      (send/suspend/callback
        `(html (head (title "page A"))
               (body (h1 "page A")
                     (p (a ((href ,callback-b)) "to page B"))
                     (p (a ((href ,callback-c)) "to page C")))))))

  (define callback-b
     (lambda (request)
      (send/suspend/callback
        `(html (head (title "page B"))
               (body (h1 "page B")
                     (p (a ((href ,callback-a)) "to page A"))
                     (p (a ((href ,callback-c)) "to page C")))))))

  (define callback-c
    (lambda (request)
      (send/suspend/callback
        `(html (head (title "page C"))
               (body (h1 "page C")
                     (p (a ((href ,callback-b)) "to page B"))
                     (p (a ((href ,callback-a)) "to page A")))))))

  (define start callback-a))

Discussion

Comments about this recipe

I would have liked to attach the full module (so people could download it and run it) but only include fragments of the code in the body of the page.

Contributors

ChrisDutchyn wrote the original code.

-- DuckySherwood - 06 Apr 2006 `

CookbookForm
TopicType:	Recipe
ParentTopic:	Web_Programming
TopicOrder:	999

Current Rev: r1.1 - 06 Apr 2006 - 17:28 GMT - DuckySherwood, Revision History:Diffs | r1.2 | > | r1.1

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