How to unencode escaped XML with xQuery

Question

I have a variable in xQuery of type xs:string with the value of an encoded HTML snippet (the content of a twitter tweet). It looks like this:

Headline

Answer 1

In MarkLogic you can use the below query:

let $d := '<a>&lt;c&gt;asdf&lt;/c&gt;</a>' 

return xdmp:unquote ($d)

Answer 2

in eXist, use util:parse():

util:parse(concat("<top>","&lt;c&gt;asdf&lt;/c&gt;",</top>")‌​)

Answer 3

Depends on which XQuery processor you are using... The easiest way is to be using a processor that has an extension that handles this for you. For instance, with Saxon and the following XML:

<a>&lt;c&gt;asdf&lt;/c&gt;</a>

You can write an XQuery that uses the saxon:parse() function to do what you want:

declare namespace saxon = "http://saxon.sf.net/";

<a>{
  saxon:parse(doc('test.xml')/a)
}</a>

The result from that is:

<a>
  <c>asdf</c>
</a>

I think most(?) XQuery processors will have an extension to do this for you. Hope that helps.