Getting the value of an element in XML in Clojure?

Question

What is the easiest way to get the value of an element from an XML string in Clojure? I am looking for something like:

(get-value "<a><b>SOMETHING</b></a>)" "b")

to return

"SOMETHING"

score 10 · Answer 1 · answered Jun 15 '11 at 10:43

10

Zippers can be handy for xml, they give you xpath like syntax that you can mix with native clojure functions.

user=> (require '[clojure zip xml] '[clojure.contrib.zip-filter [xml :as x]])

user=> (def z (-> (.getBytes "<a><b>SOMETHING</b></a>") 
                  java.io.ByteArrayInputStream. 
                  clojure.xml/parse clojure.zip/xml-zip))

user=> (x/xml1-> z :b x/text)

returns

"SOMETHING"

answered Jun 15 '11 at 10:43

user499049

564
2
6

I would suggest this as best approach as it is not only more functional but also more easy to extend once you get hang of it.. so +1 for Zipper – Ash Aug 30 '11 at 17:10

score 7 · Answer 2 · answered Jun 13 '11 at 10:37

I do not know how idiomatic Clojure it is but if you happen to know and like XPath it can be used quite easily in Clojure due to its excellent interoperability with Java:

(import javax.xml.parsers.DocumentBuilderFactory) 
(import javax.xml.xpath.XPathFactory)

(defn document [filename]
  (-> (DocumentBuilderFactory/newInstance)
      .newDocumentBuilder
      (.parse filename)))

(defn get-value [document xpath]
  (-> (XPathFactory/newInstance)
      .newXPath
      (.compile xpath)
      (.evaluate document)))

user=> (get-value (document "something.xml") "//a/b/text()")
"SOMETHING"

score 6 · Answer 3 · answered Jun 13 '11 at 11:05

6

Using Christophe Grand's great Enlive library:

(require '[net.cgrand.enlive-html :as html])

(map html/text
     (html/select (html/html-snippet "<a><b>SOMETHING</b></a>")  [:a :b]))

answered Jun 13 '11 at 11:05

Jürgen Hötzel

18,997
3
42
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Hasan Fahim · Accepted Answer · 2011-06-13T09:41:41.123

5

Try this:

user=> (use 'clojure.xml)

user=> (for [x (xml-seq 
          (parse (java.io.File. file)))
             :when (= :b (:tag x))]
     (first (:content x)))

Check this link for more info.

edited Jun 13 '11 at 09:41

answered Jun 13 '11 at 09:32

Hasan Fahim

3,875
1
30
51

score 2 · Answer 5 · answered Jun 14 '11 at 20:48

2

Using clj-xpath, ( https://github.com/brehaut/necessary-evil ) :

(use 'com.github.kyleburton.clj-xpath :only [$x:text])
($x:text "/a/b" "<a><b>SOMETHING</b></a>)")

answered Jun 14 '11 at 20:48

Laurent Petit

1,201
7
12

score 1 · Answer 6 · edited May 23 '17 at 11:53

1

Is this: Clojure XML Parsing not what you want? An alternative (external) source is here: http://blog.rguha.net/?p=510 .

edited May 23 '17 at 11:53

Community

1
1

answered Jun 13 '11 at 09:34

steenhulthin

4,553
5
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52

Getting the value of an element in XML in Clojure?

6 Answers6