Common lisp Hunchentoot/cl who页面组成

Hunchentoot/cl who页面组成

我试着在hunchentoot中整理几页作为实验，但我遇到了一堵意想不到的墙。例如，我有以下模板宏

(defmacro page-template ((&key title) &body body) `(with-html-output-to-string (*standard-output* nil :prologue t :indent t) (:html :xmlns "http://www.w3.org/1999/xhtml" :xml\:lang "en" :lang "en" (:head (:meta :http-equiv "Content-Type" :content "text/html;charset=utf-8") (:title ,(format nil "~@[~A - ~]Test Site" title))) (:body ,@body))))

---

请注意，删除了

dolist

的

mapcar

（我是一个策划人，不要让我太难喜欢lambdas，但它们在这里不是正确的选择），以及使用

htm

来转义html s-exp（h-exps？）块。否则，对于带有html输出的

，就不会有这样的上下文。最后，我必须在
（str）
中包装文本，而不是
：href
属性，以使它们能够动态展开。
将html输出为字符串的宏
使用。特别是，任何未识别的表单都保持原样，这意味着在生成html生成代码之前宏不会展开，这意味着当标准编译器展开
publish newsfeed
宏时，它不再处于
的上下文中，html输出为string
。在展开宏时，尤其是使用slime macroexpansion功能时，这一点很明显

要使其正常工作，您应该将
publish newsfeed
设置为一个函数，并将
与html输出一起使用
，并将其与相同的流一起使用（假设“到处都有标准输出”或显式传递流）

(define-easy-handler (test-page :uri "/") ()
  (page-template (:title "Splash Page") (:p "Testing testing")))
(define-easy-handler (test-feed :uri "/feeds") ()
  (page-template (:title "Splash Page") 
                 (publish-newsfeed "http://nf-one.html")
                 (publish-newsfeed "http://nf-two.html")
                 (publish-newsfeed "http://nf-three.html")))


(defmacro publish-newsfeed (url &optional (item-limit 5))
  (flet ((get-text (s-tree node-path) (car (last (xmls-tools:find-subtree s-tree node-path)))))
    (let ((rss-feed (xmls:parse (drakma:http-request url))))
      `(:div :class "rss-feed"
              (:a :href ,(get-text rss-feed '("channel" "link")) :target "_top" (:h1 ,(get-text rss-feed '("channel" "title"))))
              (:ul ,@(mapcar #'(lambda (item)
                                 `(:li (:a :href ,(get-text item '("link")) :target "_top" (:h2 ,(get-text item '("title"))))
                                       (:p :class "date" ,(get-text item '("pubDate")))
                                       (:p ,(get-text item '("description")))))
                             (let ((items (xmls-tools:find-all-children (xmls-tools:find-subtree rss-feed '("channel")) "item")))
                               (if (> (length items) item-limit) (subseq items 0 item-limit) items))))))))
(defun publish-newsfeed (url &optional (item-limit 5))
  (flet ((get-text (s-tree node-path) (car (last (xmls-tools:find-subtree s-tree node-path)))))
    (let* ((rss-feed (xmls:parse (drakma:http-request url)))
           (items (xmls-tools:find-all-children (xmls-tools:find-subtree rss-feed '("channel")) "item"))
           (ltd-items (if (> (length items) item-limit) (subseq items 0 item-limit) items)))
      (with-html-output 
       (*standard-output* nil :indent t)
       (:div :class "rss-feed"
             (:a :href (get-text rss-feed '("channel" "link")) :target "_top" (:h1 (str (get-text rss-feed '("channel" "title")))))
             (:ul (dolist (item ltd-items)
                    (htm (:li (:h2 (:a :href (get-text item '("link")) :target "_top" (str (get-text item '("title")))))
                              (:p :class "date" (str (get-text item '("pubDate"))))
                              (:p (str (get-text item '("description")))))))))))))