34 lines
831 B
Scheme
34 lines
831 B
Scheme
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;;; Copyright 2002, 2003 Andreas Bernauer
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;; outdater
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(define-record-type outdater :outdater
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(real-make-outdater outdated?)
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outdater?
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(outdated? outdater-outdated? set-outdater-outdated?!))
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(define (make-outdater)
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(real-make-outdater #f))
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(define-syntax if-outdated
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(syntax-rules ()
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((if-outdated outdater consequence alternative)
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(if (outdater-outdated? outdater)
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consequence
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(begin
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(set-outdater-outdated?! outdater #t)
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alternative)))))
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(define (show-outdated url)
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(send-html
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`(html (title "Outdated Data")
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(body (h1 "Outdated Data")
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(p "The page or action you requested relies on outdated data.")
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,(if url
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`(p "Try to "
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(url ,url "reload")
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" the page to get current data.")
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'())))))
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