如何在 Clojure 中访问表单的各个字段？

Question

我正在构建我的第一个 Web 应用程序，当用户 submits 表单时，我很难访问表单的各个字段。这是我所拥有的：

(defroutes app
  (GET "/" [] homepage)
  (POST "/city" request display-city)
  (route/resources "/")
  (route/not-found "Not Found"))


(defn display-city [request]
  (html5
     [:div {:class "the-city"}
      [:h2 "ALL ABOUT YOUR CITY"]
      [:ul
       [:li "Your city is " (str request) "! That's all"]]]))

;; and here's the hiccup form:
   [:form {:action "/city" :method "post"}
    (anti-forgery-field)
    [:p "Enter your home address"]
    [:div
     [:label {:for "street-field"} "Street:"]
     [:input {:id "street-field"
              :type "text"
              :name "street"}]]
    [:div
     [:label {:for "city-field"} "City:"]
     [:input {:id "city-field"
              :type "text"
              :name "city"}]
    [:div
     [:label {:for "state-field"} "State:"]
     [:input {:id "state-field"
              :type "text"
              :name "state"}]
     [:label {:for "zip-field"} "ZIP:"]
     [:input {:id "zip-field"
              :type "text"
              :name "zip"
              :size "10"}]]
    [:div.button
     [:button {:type "submit"} "Submit"]]]])

;;当我运行上面的代码时，我可以看到通过(str request) 提交的整个表单，看起来像是一个 Clojure 映射。但是我不知道如何提取单个“key/vals”（从那个地址表单中，我想提取城市），或者如何以我可以使用的方式存储这些结果。有什么想法吗？

这是一个超级基本的/city 页面，我试图在构建更大的东西之前了解它是如何工作的。谢谢！

Answer 1

在您的 request 映射中，应该有一个键 :form-params 带有已发布的键/值对映射。以下是您获取单个值的方法：

(get-in request [:form-params :city])

或者您可以解构 :form-params 映射以一次绑定多个值：

(let [{:keys [city state zip]} (:form-params request)]
  (format "%s, %s %s" city state zip))