XPathFunction

  • XPathFunction provides access to XPath functions, which are identified by QName and arity.

  • The primary method, evaluate, takes a list of arguments and returns the result of the function evaluation as an Object.

  • Implementations of evaluate should avoid side-effects, as the order and frequency of calls are not guaranteed.

  • If the provided arguments are incompatible with the function, an XPathFunctionException is thrown.
public interface XPathFunction

XPathFunction provides access to XPath functions.

Functions are identified by QName and arity in XPath.

Public Method Summary

abstract Object
evaluate(List args)

Evaluate the function with the specified arguments.

Public Methods

public abstract Object evaluate (List args)

Evaluate the function with the specified arguments.

To the greatest extent possible, side-effects should be avoided in the definition of extension functions. The implementation evaluating an XPath expression is under no obligation to call extension functions in any particular order or any particular number of times.

Parameters
args The arguments, null is a valid value.
Returns
  • The result of evaluating the XPath function as an Object.
Throws
XPathFunctionException If args cannot be evaluated with this XPath function.