Im using xmllint --xpath which supports only XPath 1.0. I know XPath 1.0 supports functions like concat() : https://www.w3.org/TR/1999/REC-xpath-19991116/
But I get errors like below when I try to use them in an XPath in orders to extract content from an xml document :
xmllint --debug --xpath "//*[local-name()='artifactId' and contains(text(),'log4j')]/../concat(groupId/text(),' ',artifactId/text(),' ', version/text())" ~/aax1
XPath error : Invalid expression
//*[local-name()='artifactId' and contains(text(),'log4j')]/../concat(groupId/text(),' ',artifactId/text(),' ', version/text())
xmlXPathEval: evaluation failed
XPath evaluation failure
I was reading the XPath specification. It is not clear how these functions can be used in an XPath expression ( It is clear how to use them in XSLT ). Is it possible to use them in XPath 1.0 outside the predicate ?
CodePudding user response：
XPath 1.0
A function may appear within a predicate, as you observe.
A function my also appear as a top-level expression, which can help in some situations, e.g,
concat(xp1, 'string', xp2)
where xp1 and xp2 are globally specified XPaths.
XPath 2.0
A function may appear at the last step in an XPath expression:
/e1/concat(e2, 'suffix')