How do you convert a string to a node in XQuery?

Question

I would like to convert a string into a node. I have a method that is defined to take a node, but the value I have is a string (it is hard coded). How do I turn that string into a node?

So, given an XQuery method:

define function foo($bar as node()*) as node() {
  (: unimportant details :)
}

I have a string that I want to pass to the foo method. How do I convert the string to a node so that the method will accept the string.

Does the string contain some escaped XML that you want to parse into a node, or do you just want to turn the string into a text node so that you can pass it to this particular function? — JeniT, Sep 26 '08 at 08:45

Sixty4Bit · Accepted Answer · 2008-09-23T14:49:14.853

11

MarkLogic solutions:

The best way to convert a string into a node is to use:

xdmp:unquote($string).

Conversely if you want to convert a node into a string you would use:

xdmp:quote($node).

Language agnostic solutions:

Node to string is:

fn:string($node)

edited Sep 23 '08 at 14:49

answered Sep 23 '08 at 14:15

Sixty4Bit

12,852
13
48
62

1

xdmp:unquote and quote aren't part of the XQuery language spec, it is part of a set of MarkLogic extension libraries. Loading xml from string literals into a node depends on the XQuery engine being used. http://www.xml.com/lpt/a/1660 – Jim Burger Sep 23 '08 at 14:25
Also, you're node to string code probably doesn't do what the poster wants - it will only return the concatenated string value of all nodes below $node, but not the actual XML syntax () – Martin Probst Oct 20 '08 at 12:32
I hate to accept my own answer, but this is what I was looking for and solved the problem I was having. Does the question need to be restated? – Sixty4Bit Mar 11 '09 at 22:30
It's a reasonable way to ask. You might also have asked how to parse (or de-serialize) a string into XML. – Eric Bloch Mar 06 '12 at 22:50

score 10 · Answer 2 · edited Oct 09 '13 at 06:15

10

If you want to create a text node out of the string, just use a text node constructor:

text { "your string goes here" }

or if you prefer to create an element with the string content, you can construct an element something like this:

element (some-element) { "your string goes here" }

edited Oct 09 '13 at 06:15

Sofia

771
1
8
22

answered Nov 09 '08 at 21:47

mb21 · Answer 3 · 2016-06-22T13:04:46.157

9

If you are talking about strings that contain XML markup, there are standardized solutions (from XPath/XQuery Functions 3.0) as well:

string to node: fn:parse-xml()
node to string: fn:serialize()

edited Jun 22 '16 at 13:04

answered Aug 02 '12 at 19:36

mb21

34,845
8
116
142

score 3 · Answer 4 · edited Jul 02 '13 at 07:24

The answer to this question depends on what engine is being used. For instance, users of Saxon, use the saxon:parse method.

The fact is the XQuery spec doesn't have a built in for this.

Generally speaking you would only really need to use this if you needed to pull some embedded XML from a CDATA section. Otherwise you can read files in from the filesystem, or declare XML directly inline.

For the most you would use the declarative form, instead of a hardcoded string e.g. (using Stylus studio)

declare namespace my = "http://tempuri.org";

declare function my:foo($bar as node()*) as node() {
    <unimportant></unimportant>
} ;

let $bar := <node><child></child></node>

return my:foo(bar)

score 0 · Answer 5 · answered Jun 09 '21 at 14:43

0

you also can use fn:parse-xml(xs:string) to convert your current valid XML string into a document.

answered Jun 09 '21 at 14:43

the hand of NOD

1,639
1
18
30

How do you convert a string to a node in XQuery?

5 Answers5