first

Finds and returns the first node that matches the supplied xpath.

element

The context element

path

The xpath to search for. If not supplied or nil, returns the first node matching '*'.

namespaces

If supplied, a Hash which defines a namespace mapping.

variables

If supplied, a Hash which maps $variables in the query to values. This can be used to avoid XPath injection attacks or to automatically handle escaping string values.

XPath.first( node )
XPath.first( doc, "//b"} )
XPath.first( node, "a/x:b", { "x"=>"http://doofus" } )
XPath.first( node, '/book/publisher/text()=$publisher', {}, {"publisher"=>"O'Reilly"})