Interface XPathExpression

public interface XPathExpression

XPathExpression provides access to compiled XPath expressions. The XPath evaluation is affected by the factors described in the following table.

Evaluation of XPath Expressions

Factor	Behavior
context	The type of the context is implementation-dependent. If the value is null, the operation must have no dependency on the context, otherwise an XPathExpressionException will be thrown. For the purposes of evaluating XPath expressions, a DocumentFragment is treated like a Document node.
variables	If the expression contains a variable reference, its value will be found through the XPathVariableResolver. An XPathExpressionException is raised if the variable resolver is undefined or the resolver returns null for the variable. The value of a variable must be immutable through the course of any single evaluation.
functions	If the expression contains a function reference, the function will be found through the XPathFunctionResolver. An XPathExpressionException is raised if the function resolver is undefined or the function resolver returns null for the function.
QNames	QNames in the expression are resolved against the XPath namespace context.
result	This result of evaluating an expression is converted to an instance of the desired return type. Valid return types are defined in