org.globus.ogsa
Interface ExpressionEvaluator

All Known Implementing Classes:

ServiceDataNameDeleteEvaluator, ServiceDataNameEvaluator, ServiceDataNameSetEvaluator

public interface ExpressionEvaluator

Method Summary

Object	evaluate(ExtensibilityType expression, ServiceDataSet serviceData) Evaluates the expression over a service data set and returns the result.
javax.xml.namespace.QName[]	getExpressionNames() Gets the QNames (as defined in the XML Schema of the expression) of top level expression elements that this evaluator can handle.
javax.xml.namespace.QName[]	getSDNames(ExtensibilityType expression) The Set of ServiceData names this expression acts on.

Method Detail

evaluate

public Object evaluate(ExtensibilityType expression,
                       ServiceDataSet serviceData)
                throws FaultType

Evaluates the expression over a service data set and returns the result.

Parameters:

expression - object passed by client representing query or subscription expression

serviceData - service data set associated with service instance that is to evaluate the expression

Returns:

the result of the evaluation which depends on the expression. The result must be an xml serializable object in order to be passed back correctly to a rempote client. The easiest way of achieving this is to model it as a Bean, or simply return a DOM Element. If the result object returned is null an empty query result is returned or alternatively no notification is sent out.

Throws:

FaultType - if the evaluator failed to parse or validate the expression

getExpressionNames

public javax.xml.namespace.QName[] getExpressionNames()

Gets the QNames (as defined in the XML Schema of the expression) of top level expression elements that this evaluator can handle.

Returns:

array of qnames supported by this evaluator

getSDNames

public javax.xml.namespace.QName[] getSDNames(ExtensibilityType expression)
                                       throws FaultType

The Set of ServiceData names this expression acts on.

Returns:

Set of QNames of the ServiceData.

Throws:

FaultType