Package org.mycore.common.events

Class MCREventManager

java.lang.Object

org.mycore.common.events.MCREventManager

public class MCREventManager
extends Object

Acts as a multiplexer to forward events that are created to all registered event handlers, in the order that is configured in mycore properties. For information how to configure, see MCREventHandler javadocs.

Author:

Frank Lützenkirchen

See Also:

• MCREventHandler
• MCREventHandlerBase

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	MCREventManager.MCREventHandlerInitializer

Field Summary

Fields

Modifier and Type	Field	Description
static final boolean	BACKWARD	Call event handlers in backward direction (delete)
static final String	CONFIG_PREFIX
static final boolean	FORWARD	Call event handlers in forward direction (create, update)

Method Summary

Modifier and Type	Method	Description
MCREventManager	addEventHandler(MCREvent.ObjectType type, MCREventHandler handler)	Appends the event handler to the end of the list.
MCREventManager	addEventHandler(MCREvent.ObjectType type, MCREventHandler handler, int index)	Inserts the event handler at the specified position.
MCREventManager	clear()	Clears the MCREventManager so that it contains no MCREventHandler.
MCREventHandler	getEventHandler(String mode, String propertyValue)
void	handleEvent(MCREvent evt)	Same as handleEvent( evt, MCREventManager.FORWARD )
void	handleEvent(MCREvent evt, boolean direction)	This method is called by the component that created the event and acts as a multiplexer that invokes all registered event handlers doHandleEvent methods.
static MCREventManager	instance()	The singleton manager instance
MCREventManager	removeEventHandler(MCREvent.ObjectType type)	Removes all event handler of the specified type.
MCREventManager	removeEventHandler(MCREvent.ObjectType type, MCREventHandler handler)	Removes the specified event handler.

Methods inherited from class java.lang.Object

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

Field Details

CONFIG_PREFIX

public static final String CONFIG_PREFIX

See Also:

• Constant Field Values

FORWARD

public static final boolean FORWARD

Call event handlers in forward direction (create, update)

See Also:

• Constant Field Values

BACKWARD

public static final boolean BACKWARD

Call event handlers in backward direction (delete)

See Also:

• Constant Field Values

Method Details

instance

public static MCREventManager instance()

The singleton manager instance

Returns:

the single event manager

handleEvent

public void handleEvent(MCREvent evt,
 boolean direction)

This method is called by the component that created the event and acts as a multiplexer that invokes all registered event handlers doHandleEvent methods. If something goes wrong and an exception is caught, the undoHandleEvent methods of all event handlers that are at a position BEFORE the failed one, will be called in reversed order. The parameter direction controls the order in which the event handlers are called.

Parameters:

evt - the event that happened

direction - the order in which the event handlers are called

See Also:

• MCREventHandler.doHandleEvent(org.mycore.common.events.MCREvent)
• MCREventHandlerBase

handleEvent

public void handleEvent(MCREvent evt)
                 throws MCRException

Same as handleEvent( evt, MCREventManager.FORWARD )

Throws:

MCRException

addEventHandler

public MCREventManager addEventHandler(MCREvent.ObjectType type,
 MCREventHandler handler)

Appends the event handler to the end of the list.

Parameters:

type - type of event e.g. MCRObject

addEventHandler

public MCREventManager addEventHandler(MCREvent.ObjectType type,
 MCREventHandler handler,
 int index)

Inserts the event handler at the specified position.

Parameters:

type - type of event e.g. MCRObject

index - index at which the specified element is to be inserted

removeEventHandler

public MCREventManager removeEventHandler(MCREvent.ObjectType type,
 MCREventHandler handler)

Removes the specified event handler.

Parameters:

type - type of event handler

handler - the event handler to remove

removeEventHandler

public MCREventManager removeEventHandler(MCREvent.ObjectType type)

Removes all event handler of the specified type.

Parameters:

type - type to removed

clear

public MCREventManager clear()

Clears the MCREventManager so that it contains no MCREventHandler.

getEventHandler

public MCREventHandler getEventHandler(String mode,
 String propertyValue)