edu.uci.isr.yancees.plugin
Class AbstractPlugin

java.lang.Object
  edu.uci.isr.yancees.plugin.AbstractPlugin

All Implemented Interfaces:

PluginInterface, PluginListenerInterface

Direct Known Subclasses:

AbstractCorrelationPlugin, AbstractOrderedPlugin, AbstractProtocolPlugin, AbstractSharedPlugin, ElvinPlugin, FilterPlugin, GenericPlugin, NotificationPlugin, PullPlugin, PushPlugin, RequirePlugin, RulePlugin, SequencePlugin, SienaPlugin, SubscriptionPlugin

public abstract class AbstractPlugin

extends java.lang.Object

implements PluginInterface

This abstract class defines the basic functionality of the plug-in as well as its main attributes.

Field Summary

protected java.util.Vector	myListeners
protected java.util.Vector	myRequiredPlugins

Constructor Summary

AbstractPlugin(org.w3c.dom.Node subTree)

Method Summary

void	addListener(PluginListenerInterface plugin) Makes this plug-in notify another provided plugin whenever it computers its output
void	addRequiredPlugin(PluginInterface plugin) This method is used by the subscription parser to inform the plugin of all the plug-ins that are supposed to notify this plugin when they are finished with their processing.
void	dispose() This method is part of the plug-in memory and resources management.
protected void	finalize()
long[]	getExpectedPluginIDs()
java.lang.String	getFullContext()
java.lang.String	getFullPath()
long	getId()
PluginInterface[]	getRequiredPluginsList()
org.w3c.dom.Node	getSubtree()
java.lang.String	getTag()
boolean	hasChildren() Determines whether this plug-in requires other plug-ins or not.
protected void	publishOutput(EventInterface evt) Publishes the provided output to the event dispatcher.
protected void	publishOutput(EventInterface[] evtPat) Publishes the provided event pattern to the event dispatcher
abstract void	receivePluginNotification(EventInterface[] evtList, PluginInterface source) Receives a list of events as notifications from another plug-in
abstract void	receivePluginNotification(EventInterface evt, PluginInterface source) Receives a notification from another plug-in
void	removeListener(PluginListenerInterface plugin) Removes a plug-in registered as listener of this plug-in

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

myListeners

protected java.util.Vector myListeners

myRequiredPlugins

protected java.util.Vector myRequiredPlugins

Constructor Detail

AbstractPlugin

public AbstractPlugin(org.w3c.dom.Node subTree)

Parameters:

subTree - is the DOM tree this plugin is responsible for executing

Method Detail

addRequiredPlugin

public void addRequiredPlugin(PluginInterface plugin)

This method is used by the subscription parser to inform the plugin of all the plug-ins that are supposed to notify this plugin when they are finished with their processing. This method is invoked in the BFS order in which the tags each plugin processes are parsed in the DOM tree. This information is necessary for plug-ins as the sequence detection in which the order of notifications may be important. This also prevents that plug-ins get garbage colleted, keeping required plug-ins in memory while necessary.

Specified by:

addRequiredPlugin in interface PluginInterface

getRequiredPluginsList

public PluginInterface[] getRequiredPluginsList()

Specified by:

getRequiredPluginsList in interface PluginInterface

Returns:

the list of plug-ins this plug-in depends on

hasChildren

public boolean hasChildren()

Determines whether this plug-in requires other plug-ins or not.

Specified by:

hasChildren in interface PluginInterface

Returns:

true if this plug-in requires other plug-ins or false if not

getExpectedPluginIDs

public long[] getExpectedPluginIDs()

Returns:

a list of plug-in IDs, which notifications are expected by this plugin. The result is provided in a BFS order.

getId

public long getId()

Specified by:

getId in interface PluginInterface

Returns:

the unique Id of this plugin

getTag

public java.lang.String getTag()

Specified by:

getTag in interface PluginInterface

Returns:

the tag name that this plugin is representing. It corresponds to the type of this plugin instance. For example, if this is a plug-in that handles a subtree headed by the tag, its type will be "followed-by"

getFullContext

public java.lang.String getFullContext()

Specified by:

getFullContext in interface PluginInterface

Returns:

a string separated by '/' that expresses the context, or sequence of tags from the root of a subscription DOM subtree to the subtree that this plug-in represents. For example, if this plug-in will handle the subtree headed by the tag in a subscripton like: ... ... ... its full context will be 'subscription/rule' because followed-by is inside this path. The context is the path without the tag name. This information will be part of all events produced by this component. This information helps the subscription node to identify the events coming from this component, knowing that that specific branch of his was evaluated and the answer comes in that event.

getFullPath

public java.lang.String getFullPath()

Specified by:

getFullPath in interface PluginInterface

Returns:

a string separated by '/' that expresses the path, or sequence of tags from the root of a subscription DOM subtree to the subtree that this plug-in represents. For example, if this plug-in will handle the subtree headed by the tag in a subscripton like: ... ... ... its full path will be 'subscription/rule/followed-by' This information will be part of all events produced by this component. This information helps the subscription node to identify the events coming from this component, knowing that that specific branch of his was evaluated and the answer comes in that event.

getSubtree

public org.w3c.dom.Node getSubtree()

Specified by:

getSubtree in interface PluginInterface

Returns:

the DOM subtree that is handled (and headed) by this plug-in

publishOutput

protected void publishOutput(EventInterface evt)

Publishes the provided output to the event dispatcher.

Parameters:

evt - is the event to be published to the dispather to whoever may be interested in

publishOutput

protected void publishOutput(EventInterface[] evtPat)

Publishes the provided event pattern to the event dispatcher

Parameters:

evtPat - is the event pattern to be published to the dispather to whoever may be interested in

receivePluginNotification

public abstract void receivePluginNotification(EventInterface evt,
                                               PluginInterface source)

Receives a notification from another plug-in

Specified by:

receivePluginNotification in interface PluginListenerInterface

Parameters:

evt - is the event received

source - is the plug-in sending the notification.

receivePluginNotification

public abstract void receivePluginNotification(EventInterface[] evtList,
                                               PluginInterface source)

Receives a list of events as notifications from another plug-in

Specified by:

receivePluginNotification in interface PluginListenerInterface

Parameters:

evtList - is the list of events received

source - is the plug-in sending the notification.

addListener

public void addListener(PluginListenerInterface plugin)

Makes this plug-in notify another provided plugin whenever it computers its output

Specified by:

addListener in interface PluginInterface

removeListener

public void removeListener(PluginListenerInterface plugin)

Removes a plug-in registered as listener of this plug-in

Specified by:

removeListener in interface PluginInterface

dispose

public void dispose()

This method is part of the plug-in memory and resources management. Clear all the resources allocated by this plug-in i.e. the plug-in references this plug-in depends on, as well as the listeners. This makes this object be eligible for garbage collection.

Specified by:

dispose in interface PluginInterface

finalize

protected void finalize()
                 throws java.lang.Throwable

Throws:

java.lang.Throwable