This method compiles an XPathExpression
which can then be used for (repeated) evaluations of the XPath expression.
Syntax
XPathExpression XPathEvaluator.createExpression(expression, resolver);
Parameters
- expression
- A
DOMString
representing representing the XPath expression to be created. - resolver Optional
- Permits translation of all prefixes, including the
xml
namespace prefix, within the XPath expression into appropriate namespace URIs.
Return value
A XPathExpression
representing the compiled form of the XPath expression.
Exceptions
INVALID_EXPRESSION_ERR
If the expression is not legal according to the rules of the XPathEvaluator
, an XPathException
of type INVALID_EXPRESSION_ERR
is raised.
NAMESPACE_ERR
If the expression contains namespace prefixes which cannot be resolved by the specified XPathNSResolver
, a DOMException
of type NAMESPACE_ERROR
is raised.
Example
The following example shows the use of the evaluate()
method.
HTML
<div>XPath example</div> <div>Number of <div>s: <output></output></div>
JavaScript
var xpath = "//div"; var evaluator = new XPathEvaluator(); var expression = evaluator.createExpression("//div"); var result = expression.evaluate(document, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE); document.querySelector("output").textContent = result.snapshotLength;
Result
Specifications
Specification | Status | Comment |
---|---|---|
Document Object Model (DOM) Level 3 XPath Specification The definition of 'XPathEvaluator.createExpression()' in that specification. |
Recommendation | Initial definition |
Browser compatibility
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