org.apache.velocity.app.event
Class EventCartridge

java.lang.Object
  org.apache.velocity.app.event.EventCartridge

public class EventCartridge
extends Object

Stores the event handlers. Event handlers can be assigned on a per VelocityEngine instance basis by specifying the class names in the velocity.properties file. Event handlers may also be assigned on a per-page basis by creating a new instance of EventCartridge, adding the event handlers, and then calling attachToContext. For clarity, it's recommended that one approach or the other be followed, as the second method is primarily presented for backwards compatibility.

Note that Event Handlers follow a filter pattern, with multiple event handlers allowed for each event. When the appropriate event occurs, all the appropriate event handlers are called in the sequence they were added to the Event Cartridge. See the javadocs of the specific event handler interfaces for more details.

Version:

$Id: EventCartridge.java 685685 2008-08-13 21:43:27Z nbubna $

Author:

Will Glass-Husain , Geir Magnusson Jr. , Jose Alberto Fernandez

Constructor Summary

EventCartridge()

Method Summary

boolean	addEventHandler(EventHandler ev) Adds an event handler(s) to the Cartridge.
void	addIncludeEventHandler(IncludeEventHandler ev) Add an include event handler to the Cartridge.
void	addInvalidReferenceEventHandler(InvalidReferenceEventHandler ev) Add an invalid reference event handler to the Cartridge.
void	addMethodExceptionHandler(MethodExceptionEventHandler ev) Add a method exception event handler to the Cartridge.
void	addNullSetEventHandler(NullSetEventHandler ev) Add a null set event handler to the Cartridge.
void	addReferenceInsertionEventHandler(ReferenceInsertionEventHandler ev) Add a reference insertion event handler to the Cartridge.
boolean	attachToContext(Context context) Attached the EventCartridge to the context Final because not something one should mess with lightly :)
Iterator	getIncludeEventHandlers() Iterate through all the stored IncludeEventHandlers objects
Iterator	getInvalidReferenceEventHandlers() Iterate through all the stored InvalidReferenceEventHandlers objects
Iterator	getMethodExceptionEventHandlers() Iterate through all the stored MethodExceptionEventHandler objects
Iterator	getNullSetEventHandlers() Iterate through all the stored NullSetEventHandler objects
Iterator	getReferenceInsertionEventHandlers() Iterate through all the stored ReferenceInsertionEventHandler objects
void	initialize(RuntimeServices rs) Initialize the handlers.
boolean	removeEventHandler(EventHandler ev) Removes an event handler(s) from the Cartridge.

Methods inherited from class java.lang.Object

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

Constructor Detail

EventCartridge

public EventCartridge()

Method Detail

addEventHandler

public boolean addEventHandler(EventHandler ev)

Adds an event handler(s) to the Cartridge. This method will find all possible event handler interfaces supported by the passed in object.

Parameters:

ev - object impementing a valid EventHandler-derived interface

Returns:

true if a supported interface, false otherwise or if null

addReferenceInsertionEventHandler

public void addReferenceInsertionEventHandler(ReferenceInsertionEventHandler ev)

Add a reference insertion event handler to the Cartridge.

Parameters:

ev - ReferenceInsertionEventHandler

Since:

1.5

addNullSetEventHandler

public void addNullSetEventHandler(NullSetEventHandler ev)

Add a null set event handler to the Cartridge.

Parameters:

ev - NullSetEventHandler

Since:

1.5

addMethodExceptionHandler

public void addMethodExceptionHandler(MethodExceptionEventHandler ev)

Add a method exception event handler to the Cartridge.

Parameters:

ev - MethodExceptionEventHandler

Since:

1.5

addIncludeEventHandler

public void addIncludeEventHandler(IncludeEventHandler ev)

Add an include event handler to the Cartridge.

Parameters:

ev - IncludeEventHandler

Since:

1.5

addInvalidReferenceEventHandler

public void addInvalidReferenceEventHandler(InvalidReferenceEventHandler ev)

Add an invalid reference event handler to the Cartridge.

Parameters:

ev - InvalidReferenceEventHandler

Since:

1.5

removeEventHandler

public boolean removeEventHandler(EventHandler ev)

Removes an event handler(s) from the Cartridge. This method will find all possible event handler interfaces supported by the passed in object and remove them.

Parameters:

ev - object impementing a valid EventHandler-derived interface

Returns:

true if event handler was previously registered, false if not found

getReferenceInsertionEventHandlers

public Iterator getReferenceInsertionEventHandlers()

Iterate through all the stored ReferenceInsertionEventHandler objects

Returns:

iterator of handler objects, null if there are not handlers

Since:

1.5

getNullSetEventHandlers

public Iterator getNullSetEventHandlers()

Iterate through all the stored NullSetEventHandler objects

Returns:

iterator of handler objects

Since:

1.5

getMethodExceptionEventHandlers

public Iterator getMethodExceptionEventHandlers()

Iterate through all the stored MethodExceptionEventHandler objects

Returns:

iterator of handler objects

Since:

1.5

getIncludeEventHandlers

public Iterator getIncludeEventHandlers()

Iterate through all the stored IncludeEventHandlers objects

Returns:

iterator of handler objects

getInvalidReferenceEventHandlers

public Iterator getInvalidReferenceEventHandlers()

Iterate through all the stored InvalidReferenceEventHandlers objects

Returns:

iterator of handler objects

Since:

1.5

attachToContext

public final boolean attachToContext(Context context)

Attached the EventCartridge to the context Final because not something one should mess with lightly :)

Parameters:

context - context to attach to

Returns:

true if successful, false otherwise

initialize

public void initialize(RuntimeServices rs)
                throws Exception

Initialize the handlers. For global handlers this is called when Velocity is initialized. For local handlers this is called when the first handler is executed. Handlers will not be initialized more than once.

Parameters:

rs -

Throws:

Exception

Since:

1.5