update xml attribute value

[siyu798]

Hi,

  Does anyone know how to update xml element attribute value on the zipper data structure?

I have something like

<root>

    <element1 name="x1" description="d1"/>

    <element2 name="x2" description="d2"/>

</root>

(:require (clojure [xml :as xml] [zip :as zip]) 

     [clojure.contrib.zip-filter.xml :as zf])

(let

  [src (-> "c:/my.xml" io/file xml/parse zip/xml-zip)

   edf (zf/xml1-> src :root :element1)

   n    (-> (zf/attr :description) (zip/replace "dddd"))])

and this is giving me java.lang.ClassCastException: java.lang.Character cannot be cast to clojure.lang.Associative (test-xml-zip.clj:0)

Thanks,

[Allen Johnson]

Given that 'loc is the proper location in your zipper:

(zip/edit loc assoc-in [:attrs :description] "new value")

Allen

[siyu798]

Thanks Allen, it works, I did not know the loc can be treated like a hash.

siyu

[Allen Johnson]

> Thanks Allen, it works, I did not know the loc can be treated like a hash.

'loc itself isn't a map even though zip/edit makes it seem that way.
Behind the scenes zip/edit calls (zip/node loc) which will return a
map, at least in the case of this xml example. zip/edit then applies
the function you provided (assoc-in) to this map plus any supplied
args. The result of this replaces the node at loc.

https://github.com/clojure/clojure/blob/59b65669860a1f33825775494809e5d500c19c63/src/clj/clojure/zip.clj#L210

Allen