用于匹配尾部斜杠的 Compojure 正则表达式

Question

也许我只是个白痴，但我无法在 Clojure 中为可选的尾部斜杠设置匹配。

lein repl
REPL started; server listening on localhost port 47383
user=> (use 'ring.mock.request 'clout.core)
nil
user=> (route-matches "/article/" (request :get "/article/"))
{}
user=> (route-matches "/article/?" (request :get "/article"))
nil
user=> (route-matches "/article/?" (request :get "/article/"))
nil
user=> (route-matches #"/article/?" (request :get "/article/"))
java.lang.IllegalArgumentException: No implementation of method: :route-matches of protocol: #'clout.core/Route found for class: java.util.regex.Pattern (NO_SOURCE_FILE:0)

我可以使用什么正则表达式来匹配 Compojure 中的可选尾部斜杠？

Answer 1

clout 期望作为 route-matches 的第一个参数的路径字符串不是正则表达式，而是可以包含关键字和 * 的字符串通配符。

我相信 clout 本身并不支持定义忽略尾部斜杠的路由。您可以使用删除尾部斜杠的中间件函数来解决该问题。以下函数取自旧版本的compojure源代码（在大重构之前），我无法确定它们是否移动到了新的地方。这是引入这些函数的原始提交。

(defn with-uri-rewrite
  "Rewrites a request uri with the result of calling f with the
   request's original uri.  If f returns nil the handler is not called."
  [handler f]
  (fn [request]
    (let [uri (:uri request)
          rewrite (f uri)]
      (if rewrite
        (handler (assoc request :uri rewrite))
        nil))))

(defn- uri-snip-slash
  "Removes a trailing slash from all uris except \"/\"."
  [uri]
  (if (and (not (= "/" uri))
           (.endsWith uri "/"))
    (chop uri)
    uri))

(defn ignore-trailing-slash
  "Makes routes match regardless of whether or not a uri ends in a slash."
  [handler]
  (with-uri-rewrite handler uri-snip-slash))

Answer 2

这是没有依赖项的中间件的精简版本：

(defn with-ignore-trailing-slash [handler] (fn [request]
  (let [uri       (request :uri)
        clean-uri (if (and (not= "/" uri) (.endsWith uri "/"))
                    (subs uri 0 (- (count uri) 1))
                    uri)]
    (handler (assoc request :uri clean-uri)))))

欢迎错误修复编辑。

Answer 3

对于那些寻找更压缩解决方案的人:)

(defn- with-ignore-trailing-slash [handler]
  (fn [request]
    (let [uri (request :uri)
          clean-uri (str/replace uri #"^(.+?)/+$" "$1")]
      (handler (assoc request :uri clean-uri)))))