Odysseus allows to implement additional constant variables. For this, the developer has to implement the interface IReplacementProvider from the bundle de.uniol.inf.is.odysseus.script.parser. The implementation has to be provided as a service, then. The interface is as follows:
public interface IReplacementProvider {
public Collection<String> getReplacementKeys();
public String getReplacementValue( String replacementKey );
}
The method getReplacementKeys() has to return a collection of keys which the provider wants to offer. This will be called each time before a OdysseusScript-File is executed (so the list of available keys can change during run-time, if needed). The second method getReplacementValue() finally has to return the value for the given key. It is expected that since the provider provides the key, a value non-null is retured. If the second method return null, OdysseusScript uses an empty string (""). The method is called each time the key is used inside one OdysseusScript file.