org.globus.wsrf
Interface TopicExpressionEvaluator

All Known Implementing Classes:

SimpleTopicExpressionEvaluator

public interface TopicExpressionEvaluator

A TopicExpressionEvaluator is used to implement a topic expression evaluation against a TopicList. An evaluator can be registered with a TopicExpressionEngine, which in turn calls the evaluator when a matching expression is found.

See Also:

TopicList, TopicExpressionEngine

Method Summary

List	getConcreteTopicPath(Object expression) Converts the expression from dialect specific form to a ordered list of QNames.
URI[]	getDialects() Gets the URIs for the dialects that this evaluator can handle
Collection	resolve(Object expression, TopicList topicList) Evaluates the expression over a TopicList and returns the result.
TopicExpressionType	toTopicExpression(List topicPath) Converts a topic path (list of QNames) to a dialect specific concrete topic expression.

Method Detail

resolve

public Collection resolve(Object expression,
                          TopicList topicList)
                   throws Exception

Evaluates the expression over a TopicList and returns the result.

Parameters:

expression - object passed by client representing the topic expression

topicList - topic list associated with the service/resource

Returns:

the result of the evaluation which depends on the expression.

Throws:

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

getDialects

public URI[] getDialects()

Gets the URIs for the dialects that this evaluator can handle

Returns:

array of URIs supported by this evaluator

getConcreteTopicPath

public List getConcreteTopicPath(Object expression)
                          throws Exception

Converts the expression from dialect specific form to a ordered list of QNames. This method throws an exception if the expression does not evaluate to a concrete topic path.

Parameters:

expression - object passed by client representing the topic expression

Returns:

a list of QNames describing the concrete topic path

Throws:

Exception -

toTopicExpression

public TopicExpressionType toTopicExpression(List topicPath)
                                      throws Exception

Converts a topic path (list of QNames) to a dialect specific concrete topic expression.

Parameters:

topicPath - containing a list of QNames describing a concrete topic path

Returns:

dialect specific version of the topic path

Throws:

Exception -