klyn.io.xml.xpath.DOMXPathEvaluator.selectSingleNode
method

    public selectSingleNode(expression as String, contextNode as Node, resolver as XPathNSResolver = null) as Node throws XPathException, DOMException:

Description

Evaluates an XPath expression and returns its first matching node.

This is a Klyn convenience method for the common single-node lookup case. It returns `null` when no node matches.

Parameters

Parameter | Description
--- | ---
`expression` | XPath expression selecting nodes.
`contextNode` | Context node.
`resolver` | Namespace resolver, or `null`.

Returns

First matching node, or `null`.

Throws

- XPathException if the expression cannot be converted to a node set.
- DOMException if the context node is invalid.

Example

    node = DOMXPathEvaluator().selectSingleNode("/Spies/Spy[@id='007']", document)
    if node is not null:
    print(node.nodeName)