edu.umd.cfar.lamp.apploader.prefs
Interface TriggerHandler

All Known Implementing Classes:

PrintUsage, PrintVersion, PropsToPrefs

public interface TriggerHandler

A TriggerHandler is created and invoked when a preference is set (a preference trigger or flag) and an instance of the property is found on the command line or in the java properties set on start-up of the application. An example of a trigger is a command line key/value pair. Upon finding a trigger, the application loader uses the preferences to find an implementation of TriggerHandler to invoke. A flag is like a trigger, but it does not take a value. They share an interface (this one, TriggerHandler, for convenience. The initial idea was just to convert the values into RDF triples, but you are free to do whatever you wish upon handling a trigger. For example, a '--help' flag may either add a javabeans property set method in the preference model that turns on 'help' mode, or it may invoke the PrintUsage handler, which prints usage to the command line and exits the program.

Author:

davidm

Method Summary

void	invoke(PrefsManager prefs, com.hp.hpl.jena.rdf.model.Resource def, java.lang.String value) Invokes the given trigger using the given command line value, if it exists.

Method Detail

invoke

public void invoke(PrefsManager prefs,
                   com.hp.hpl.jena.rdf.model.Resource def,
                   java.lang.String value)

Invokes the given trigger using the given command line value, if it exists.

Parameters:

prefs - The preferences to modify.

def - The RDF resource that defined the handler

value - The value passed from the command line or java property.