fn:root
The root of the tree that contains the argument
Description
The fn:root function returns a document node if the $arg node is part of a document, but it may also return an element if the $arg node is not part of a document.
Calling the fn:root function is similar to starting a path with / or /. It is more flexible in that it can appear anywhere in a path or other expression. Also, unlike starting with a path with /, the fn:root function does not require the root to be a document node; it could be an element in the case of a document fragment.
This description is © Copyright 2007, Priscilla Walmsley. It is excerpted from the book XQuery by Priscilla Walmsley, O'Reilly, 2007. For a complete explanation of this function, please refer to Appendix A of the book.
Arguments and Return Type
| Name | Type | Description |
|---|---|---|
$arg |
node()? |
the node to find the root of |
| return value | node()? |
Examples
<xsl:variable name="in-xml" as="item()*"> | ||
| ||
</xsl:variable> |
| XPath Example | Results |
|---|---|
root(
doc('https://www.datypic.com/functx./input/order.xml')
//item[1]) |
The document node of order.xml |
root($in-xml/x) |
<a>
<x>123</x>
</a> |
History
| Published On | Last Updated | Contributor(s) |
|---|---|---|
| 2006-06-27 | 2007-02-26 | W3C, XQuery 1.0 and XPath 2.0 Functions and Operators, http://www.w3.org/TR/xpath-functions/ |
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