61 lines
1.7 KiB
Scheme
61 lines
1.7 KiB
Scheme
(define-structure surflet surflet-interface
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(open surflets
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surflets/utilities ;form-query-list
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surflet-requests
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surflet-handler/primitives
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httpd-responses
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url
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scheme-with-scsh)
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(begin
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(define (get-number input-text . maybe-title)
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(let* ((title (if (pair? maybe-title) (car maybe-title) #f))
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(result
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(send-html/suspend
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(lambda (new-url)
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`(html ,(if title
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`(title ,title) '())
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(body
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,(if title `(h2 ,title) '())
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(p
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(form (@ (method "get")
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(action ,new-url))
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,input-text " "
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(input (@ (type "text")
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(name "number"))
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(input (@ (type "submit"))))))
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(hr)
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(p (url "/" "Return to main menu") (br)
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(url "add-html.scm" "Start new calculation."))))))))
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(let* ((bindings (form-query-list
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(http-url-search (surflet-request-url result))))
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(number (string->number
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(extract-single-binding "number" bindings))))
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(if number
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number
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(get-number input-text "Please enter a valid number")))))
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(define (get-number1)
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(get-number "First number:" "Calculation - Step one"))
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(define (get-number2)
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(get-number "Second number:" "Calculation - Step two"))
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(define (main req)
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(let ((req
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(send-html/suspend
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(lambda (new-url)
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`(html (title "Result")
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(body (h2 "Result")
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(p ,(number->string (+ (get-number1) (get-number2))))
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(hr)
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(a (@ (href "add-html.scm")) "New calculation (new session)")(br)
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(a (@ (href "javascript:history.go(-2)")) "New calculation (same session)")(br)
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(a (@ (href ,new-url)) "Close this session")))))))
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;; How to clear session data and go to another HTML page:
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(send-error (status-code temp-redirect) req
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"/" "/")
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))
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; ))
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))
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