JavaScript - createExpression() method

revision: February 14, 2024

Category : document

The createExpansion() method compiles an XPathExpression which can then be used for (repeated) evaluations. You must call this method on the same document that you run the expression against.

Syntax :

        createExpression(xpathText, namespaceURLMapper)
    

Parameters:

xpathText : a string which is the XPath expression to be compiled.

namespaceURLMapper : a function which maps a namespace prefix to a namespace URL (or null if none needed).

Examples:

            const xpathExpr = document.createExpression("//div");
            const xpathResult = xpathExpr.evaluate(document); // returns an XPathResult object
            const nodeContext = document.querySelector("nav");
            // Re-using the XPathExpression "xpathExpr"
            const otherResult = xpathExpr.evaluate(nodeContext); // returns an XPathResult object
        

Practical examples