org.deegree.filter
Interface XPathEvaluator<T>

Type Parameters:

T - object type that this evaluator works on

All Known Implementing Classes:

FeatureXPathEvaluator

public interface XPathEvaluator<T>

Implementations enable the evaluation of XPath expressions (given as ValueReferences) on a specific class of objects, e.g. Feature instances.

Version:

$Revision: 31660 $, $Date: 2011-08-25 20:48:53 +0200 (Thu, 25 Aug 2011) $

Author:

Markus Schneider, last edited by: $Author: mschneider $

Method Summary

TypedObjectNode[]	eval(T context, ValueReference valueRef) Returns the values that are selected by evaluating the given XPath 1.0 expression using the context object.
String	getId(T context) Returns the identifier of the given context object.

Method Detail

eval

TypedObjectNode[] eval(T context,
                       ValueReference valueRef)
                       throws FilterEvaluationException

Returns the values that are selected by evaluating the given XPath 1.0 expression using the context object.

Parameters:

context - object that the expression is evaluated upon, must not be null

valueRef - value reference, must not be null

Returns:

the selected values, never null and contains at least one entry

Throws:

FilterEvaluationException - if an exception occurs during the evaluation of the XPath expression

getId

String getId(T context)

Returns the identifier of the given context object.

Parameters:

context - context object, never null

Returns:

the identifier, can be null