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Javascript Document.evalute failing with 'name()' in XPath

I am attempting to use the Javascript Document evaluate function with valid XPath that uses the name() / local-name() function but am consistently getting the following error in Jfiddle:

The string '/foods/*[position()=1</a>/local-name()' is not a valid XPath expression

It is unclear how or why the </a> fragment is introduced

Sample code is as follows:

const xml = "<foods><meat>chicken</meat><fruit>orange</fruit><fruit>apple</fruit><fruit>banana</fruit></foods>";

const doc = new DOMParser().parseFromString(xml,'application/xml');

for ( var i = 0 ; i < 4; i++ ){
const xpath = `/foods/*[position()=${i+1}]`;
const xpathValue = document.evaluate(
  xpath,
  doc,
  null,
  XPathResult.STRING_TYPE,
  null
);
const xpathName = document.evaluate(
  `${xpath}/local-name()`,
  doc,
  null,
  XPathResult.STRING_TYPE,
  null
);

console.log(`${xpathName.stringValue} = ${xpathValue.stringValue}`);
}

The XPath evalutaing the value works fine, just not the node name. Any assistance would be appreciated.

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    Thanks @Martin Honnen - working code

    onst xml = "<foods><meat>chicken</meat><fruit>orange</fruit><fruit>apple</fruit><fruit>banana</fruit></foods>";

const doc = new DOMParser().parseFromString(xml,'application/xml');

for ( var i = 0 ; i < 4; i++ ){
const xpath = `/foods/*[position()=${i+1}]`;
const xpathValue = doc.evaluate(
  xpath,
  doc,
  null,
  XPathResult.STRING_TYPE,
  null
);
let resolver = function () { return "http://www.w3.org/2005/xpath-functions";}
const xpath2 = `name(/foods/*[position()=${i+1}])`;
console.log(xpath2);
const xpathName = doc.evaluate(
  xpath2,
  doc,
  resolver,
  XPathResult.STRING_TYPE,
  null
);

console.log(`${xpathName.stringValue} = ${xpathValue.stringValue}`);
}

  2. 0

    You can use XPath 3.1 with SaxonJS 2:

    const xml = "<foods><meat>chicken</meat><fruit>orange</fruit><fruit>apple</fruit><fruit>banana</fruit></foods>";

const doc = new DOMParser().parseFromString(xml,'application/xml');

const result = SaxonJS.XPath.evaluate(`/foods/*/(name() || ' = ' || string())`, doc);

console.log(result);
    <script src="https://martin-honnen.github.io/SaxonJS-2.6/SaxonJS2.js"></script>
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