如何使用Hiccup和Compojure在Clojure中编写数学功能?

时间:2014-02-27 07:16:41

标签: clojure clojurescript compojure hiccup

我有一个home页面正在呈现请求用户输入为整数向量。我需要那些数据结构,因为它们与我将用来操作输入的数学函数相配得很好:

(defn home [& [weights grades error]]
  (html
    ;; ...
   (form-to [:post "/"]
    ;; ...
    (text-area {:rows 15 :cols 30 :placeholder
"[89 78 63]
                    [78 91 60]
                    [87 65 79]
                    ..." } "grades" grades)]
     (submit-button "process"))]))

"process"按钮使用defroutes方法通过POST函数发送输入,该方法调用呈现processed html的{​​{1}}方法输入结果。用于计算最终成绩列表的函数称为process-grades。我试图使用read-string将输入数据结构更改为我的函数可以处理的内容,但无法使其工作。当我使用processed替换"TEST"的来电时,在点击process按钮后呈现文字时没有问题:

(defn process-grades 
  "Takes user input from home's form-to function and processes it into the final grades list"
  [weights grades]
(->> grades
     (map (partial percentify-vector weights))
     (mapv #(apply + %))))

(defn processed [weights grades]
  (cond
   (empty? weights)
   (home weights grades "You forgot to add the weights!")
   (empty? grades)
   (home weights grades "You forgot to add the grades!")
  :else
  (do
  (html  
   [:h2 "These are your final grades."]
   [:hr]
   [:p (process-grades (read-string weights)(read-string grades))])))) ;; <- This is not working!


(defroutes grade-routes
           (GET "/" []
                {:status 200
                 :headers {"Content-Type" "text/html"}
                 :body (home)
                 })
           (POST "/" [weights grades] (processed weights grades))
           (ANY "*" []
                (route/not-found (slurp (io/resource "404.html")))))

我对html form标记,Clojure的read-string函数以及编写我需要的功能的各种方法进行了一些研究。由于信息过剩,我仍然想知道:最简单,最简洁,最惯用的方法是什么?我应该找到Clojurescript还是可以在这里使用Vanilla风味的JVM Clojure?

1 个答案:

答案 0 :(得分:1)

您收到错误,因为(process-grades)正在返回数字向量,这意味着下面的表格

[:p (process-grades (read-string weights) (read-string grades))]

最终会看起来如下(一旦process-grades返回):

[:p [4/5 3/2 6/3 ... more numbers]]

Hiccup只知道如何在每个打嗝矢量的开头处理关键字html标签,所以它会大声抱怨这个。

最终你需要以你想要的方式很好地格式化输出,但是暂时你应该能够通过在(process-grades ...)中包含(apply str)调用来使其运行矢量成一个字符串。