Question

我正在尝试使用clj-xpath解析一些xml，基本上我想创建一个看起来像这样的函数

(map
         (fn [item]
           {:title ($x:text "./title" item)
            :url  ($x:text "./url" item)})
         (take 5
               ($x "/search/events/event" (xmldoc))))

但是使用任意标签。到目前为止，我有这个

ns mashup-dsl.datamodel
(:use
    [clj-xpath.core])
(def data-url "http://api.eventful.com/rest/events/search?  app_key=4H4Vff4PdrTGp3vV&keywords=music&location=Belgrade&date=Future")

(def events-xml
 (fn [] (slurp data-url)))

(def xmldoc
  (fn [] (xml->doc (events-xml))))

(def item (take 5 ($x "/search/events/event" (xmldoc))))

(defn create-xpath [tag] (str "./" tag))

(def tags ["title" "url"])

(defn parse [item]
    (doseq [tag tags])(into {} (keyword tag) ($x:text (create-xpath tag) item)))

但是我收到了这个错误，TransformerException额外的非法令牌：'$'，'tag'，'@'，'64516c52'org.apache.xpath.compiler.XPathParser.error（XPathParser.java:610）。所以问题在于解析功能。有什么想法吗？

Answer 1

以下是如何提取前5个标题：

user=> (map #($x:text "./title" %) (take 5 ($x "//event" (xmldoc))))
("9th International Belgrade Early Music Festival" "Belgrade Baroque Academy, Mijanovic, Gosta / 9th Belgrade Early Music Festival / Monteverdi: \"L'Incoronazione di Poppea\"" "Belgrade Baroque Academy, Mijanovic, Gosta / 9th Belgrade Early Music Festival / Monteverdi: \"L'Incoronazione di Poppea\"" "ICTM Study Group on Music and Dance in Southeastern Europe Conference" "New Belgrade Opera, Madlenianum Opera-Theatre, New Trinity Baroque; Mijanovic, Gosta / 9th Belgrade Early Music Festival / Monteverdi: \"L'incoronazione di Poppea\"")

您的示例doseq未正确关闭，您需要编译表达式以用于xml->doc结果。

您可以创建一个辅助函数，它将返回从标记中提取文本的函数：

(defn tag-fn [tag] (partial $x:text tag))

现在，您可以为＆＃34; title＆＃34;生成功能。和＆＃34; url＆＃34;：

user=> (tag-fn "title")
#<core$partial$fn__4190 clojure.core$partial$fn__4190@71cc2b7a>

和

user=> (map (tag-fn "title") (take 5 ($x "//event" (xmldoc))))
("9th International Belgrade Early Music Festival" "Belgrade Baroque Academy, Mijanovic, Gosta / 9th Belgrade Early Music Festival / Monteverdi: \"L'Incoronazione di Poppea\"" "Belgrade Baroque Academy, Mijanovic, Gosta / 9th Belgrade Early Music Festival / Monteverdi: \"L'Incoronazione di Poppea\"" "ICTM Study Group on Music and Dance in Southeastern Europe Conference" "New Belgrade Opera, Madlenianum Opera-Theatre, New Trinity Baroque; Mijanovic, Gosta / 9th Belgrade Early Music Festival / Monteverdi: \"L'incoronazione di Poppea\"")

或网址和标题：

user=> (map (juxt (tag-fn "url") (tag-fn "title")) (take 2 ($x "//event" (xmldoc))))
(["http://eventful.com/belgrade/events/9th-international-belgrade-/E0-001-064654999-7@2014061420?utm_source=apis&utm_medium=apim&utm_campaign=apic" "9th International Belgrade Early Music Festival"] ["http://eventful.com/belgrade/events/belgrade-baroque-academy-mijanovic-gosta-9th-belg-/E0-001-059734872-8?utm_source=apis&utm_medium=apim&utm_campaign=apic" "Belgrade Baroque Academy, Mijanovic, Gosta / 9th Belgrade Early Music Festival / Monteverdi: \"L'Incoronazione di Poppea\""])

或网址和标题：

user=> (map (apply juxt (map tag-fn ["url" "title"])) (take 2 ($x "//event" (xmldoc))))
(["http://eventful.com/belgrade/events/9th-international-belgrade-/E0-001-064654999-7@2014061420?utm_source=apis&utm_medium=apim&utm_campaign=apic" "9th International Belgrade Early Music Festival"] ["http://eventful.com/belgrade/events/belgrade-baroque-academy-mijanovic-gosta-9th-belg-/E0-001-059734871-9?utm_source=apis&utm_medium=apim&utm_campaign=apic" "Belgrade Baroque Academy, Mijanovic, Gosta / 9th Belgrade Early Music Festival / Monteverdi: \"L'Incoronazione di Poppea\""])

Answer 2

最简单的形式是：

  (def url 
      (str 
          "http://api.eventful.com/rest/events/search?"
          "app_key=4H4Vff4PdrTGp3vV&"
          "keywords=music&"
          "location=Tokyo&"
          "date=Future"))
  (def xml (slurp url))
  (def event-titles (map #($x:text "./title" %) ($x "//event" xml)))

事件标题的打印输出将是：

（＆＃34; FLOPPY 10周年纪念「这是电脑音乐'＆＃34;＆＃34; IN BUSINESS＆＃34; ＆＃34; UNIT 10周年勃起＆＃34; ＆＃34;在0＆＃34; ＆＃34; \＆＃34; 20140530 - 生病团队发布党\＃34;＆＃34; ＆＃34; Fanfare Ciocarlia @ World Beat Festival＆＃34; ＆＃34; Fanfare Ciocarlia @ Musashino Hall＆＃34; ＆＃34; DBS呈现PINCH生日击!!!＆＃34; ＆＃34;布鲁斯姐妹（来自尊重）＆＃34; ＆＃34; UNIST第二名专辑「Acoustic」リリースパーティー「リリースしちゃってウカれ夜（ドヤッ）☆」＆＃34;）

修改对于多功能功能，您可以定义：

(defn search-for [tag local-path] (map #($x:text (str (local-path) %) ($x (str "//" tag) *xml*)))

并使用它：

(search-for "event" "@id")

或

(search-for "event" "./title")

或

(search-for "image" "./url")

使用clj-xpath用任意标签解析clojure中的xml

2 个答案: