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;;;; -*- mode: lisp -*-
;;;;
;;;; $Id: helloworld1.lisp,v 1.11 2004/09/09 11:21:37 sven Exp $
;;;;
;;;; The 'Reddit.lisp' example featured in the Lisp Movie:
;;;; Episode 2: (Re)writing Reddit in Lisp is 20 minutes and 100 lines
;;;; See: http://homepage.mac.com/svc/LispMovies/index.html
;;;;
;;;; This example is *not* loaded automatically by the ASDF :kpax-examples
;;;; since it needs S-HTTP-CLIENT (load this dependency first)
;;;;
;;;; Copyright (C) 2005 Sven Van Caekenberghe, Beta Nine BVBA. All Rights Reserved.
;;;;
;;;; You are granted the rights to distribute and use this software
;;;; as governed by the terms of the Lisp Lesser GNU Public License
;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
;;;;
(in-package :kpax-user)
(defwebapp :reddit
(:index 'reddit-home)
(:static-root "static/")
(:unsecure t))
(defvar *id-counter* 0)
(defclass reddit-link ()
((url :reader get-url :initarg :url :initform nil)
(title :reader get-title :initarg :title :initform "")
(id :reader get-id :initform (incf *id-counter*))
(timestamp :reader get-timestamp :initform (get-universal-time))
(points :accessor get-points :initform 0)))
(defvar *all-links* '())
(defun add-new-link (url title)
(push (make-instance 'reddit-link :url url :title title) *all-links*))
(defun get-sorted-links (sort-by)
(let ((links (sort (copy-list *all-links*) #'> :key sort-by)))
(subseq links 0 (min (length links) 25))))
(defun get-link-with-id (id)
(find id *all-links* :key #'get-id))
(defun render-link (request-response link)
(with-slots (url title timestamp points id)
link
(html-part (out request-response)
(:li
(:a :href url :title url (str title))
(fmt "Posted ~a ago. ~d point~:p. " (s-utils:format-duration (max 1 (- (get-universal-time) timestamp))) points)
(:a :href (dynamic-url request-response 'reddit-up :id id) :title "Vote this link up" "Up")
(:a :href (dynamic-url request-response 'reddit-down :id id) :title "Vote this link down" "Down")))))
(defun reddit-home (request-response)
(html-page (out request-response)
(:html
(:head
(:title "Reddit.lisp")
(:link :rel "stylesheet" :type "text/css" :href (static-url request-response :webapp "reddit.css")))
(:body
(:h1 "Reddit.lisp") (:h3 "In less than 100 lines of elegant code")
(:p
(:a :href (dynamic-url request-response nil) :title "Reload the Reddit.lisp Home page" "Refresh")
(:a :href (dynamic-url request-response 'reddit-new-link) :title "Submit a new link" "New link"))
(:h2 "Highest Ranking Links")
(:ol
(loop :for link :in (get-sorted-links #'get-points) :do
(render-link request-response link)))
(:h2 "Lastest Links")
(:ol
(loop :for link :in (get-sorted-links #'get-timestamp) :do
(render-link request-response link)))))))
(defun reddit-new-link (request-response &optional message)
(html-page (out request-response)
(:html
(:head
(:title "Reddit.lisp - Submit a new link")
(:link :rel "stylesheet" :type "text/css" :href (static-url request-response :webapp "reddit.css")))
(:body
(:h1 "Reddit.lisp") (:h3 "Submit a new link")
(when message (htm (:p (str message))))
(:form :action (dynamic-url request-response 'reddit-submit-new-link) :method "post"
(:input :type "text" :name "url" :value "http://" :size 48 :title "The URL of the new link")
(:input :type "text" :name "title" :value "Title" :size 48 :title "The title of the new link")
(:input :type "submit" :value "I Read It !"))
(:p (:a :href (dynamic-url request-response nil) :title "Back to the Reddit.lisp Home page" "Home"))))))
(defun is-valid-url (url)
(ignore-errors
(multiple-value-bind (contents code)
(s-http-client:do-http-request url)
(and (stringp contents) (not (zerop (length contents))) (= 200 code)))))
(defun reddit-submit-new-link (request-response)
(let ((url (get-request-parameter-value request-response "url"))
(title (get-request-parameter-value request-response "title")))
(cond ((or (null url) (equal url "") (equal url "http://"))
(reddit-new-link request-response "URL missing"))
((or (null title) (equal title "") (equal title "Title"))
(reddit-new-link request-response "Title missing"))
((is-valid-url url)
(add-new-link url title)
(redirect-to request-response 'reddit-home))
(t (reddit-new-link request-response "URL is not valid")))))
(defun reddit-up (request-response &optional (delta +1))
(let* ((id (s-utils:parse-integer-safely (get-request-parameter-value request-response "id")))
(link (find id *all-links* :key #'get-id)))
(when link (incf (get-points link) delta))
(redirect-to request-response 'reddit-home)))
(defun reddit-down (request-response)
(reddit-up request-response -1))
;;;; eof
|
