Description

xwiki-activity component

• xwiki-activity component
  • Goals
  • Prerequisities
  • Architecture proposal
  • Storage
    • PersistenceCapableEvent
    • activity.hbm.xml
  • Questions

Goals

Short-term: Log events fired by xwiki-observation into a dedicated table in the database, allowing cheap retrieval of activity within various scopes: farm, wiki, space.
Short-term: Use this component as a datasource for the notification module (watchlist).
Long-term: Use this component as a datasource for the statistics module.

Prerequisities

Additions to org.xwiki.observation.event.Event

Event getParent()
Date getDate()
Source getSource()
Data getData()

Creation of:

• org.xwiki.observation.event.EventCriteria (Used by EventListeners to registers to events)

Addition to AbstractDocumentEvent:
public abstract class AbstractDocumentEvent implements Event, Serializable

Only one notify method:
org.xwiki.observation.internal#DefaultObservationManager#notify(Event event)

DocumentUpdateEventCriteria criteria = new DocumentUpdateEventCriteria();
criteria.setSpaceFilter(new ExactStringFilter("Main"));
criteria.setCreationDateFilter(new DateBeforeFilter("200801010000"));

Architecture proposal

• xwiki-event/
  • xwiki-event-observation/
    • xwiki-event-observation-local/
      • 
        
    • xwiki-event-observation-remote/
  • xwiki-event-persistence/
    • internal/
      • PersistenceCapableEvent.java (Flattened version of Event)
      • PersistenceEventListener.java (implements org.xwiki.observation.EventListener)
      • DefaultEventPersistenceConfiguration.java (stores all events defined by the configuration)
      • DefaultEventStore.java (short term: implementation in a plugin or xwiki-core, bridge between 1.0 and 2.0 configuration)
    • EventPersistenceConfiguration.java (configure which events the listener must listen to)
    • EventStore.java
      • void addEvent(Event)
      • void removeEvent(Event)
      • List<Event> getEvents(EventCriteria)

/**
 * All Event types must implement this interface.
 */
public interface Event
{    
    Event getParent();
    
    Date getDate();
    
    Object getSource();
    
    Object getData();
    
    String getUser();
    
    String getWiki();
    
    String getSpace();
    
    String getPage();
}

Storage

PersistenceCapableEvent

Notes:

• EventStore implementation must implement a storage queue and process it with another thread (see statistics implementation).
• EventStore must rely on xwiki-query to retrieve events from the database (if possible).

String getId()
String getParent()
Date getDate()
String getType() /* Example: org.xwiki.observation.event.DocumentSaveEvent */
String getSource()
String getUser()
String getWiki()
String getSpace()
String getPage()
String getData()

activity.hbm.xml

<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="org.xwiki.activity.internal.DefaultActivityEvent" table="activityevent"> <id name="id" type="string" unsaved-value="undefined"> <column name="id" length="255" not-null="true" /> <generator class="assigned" /> </id> <property name="date" type="timestamp"> <column name="date" /> </property> <property name="type" type="string"> <column name="type" length="255" /> </property> <property name="user" type="string"> <column name="user" length="255" /> </property> <property name="wiki" type="string"> <column name="wiki" length="255" /> </property> <property name="space" type="string"> <column name="space" length="255" /> </property> <property name="page" type="string"> <column name="page" length="255" /> </property> <property name="string1" type="string"> <column name="string1" length="255" /> </property> <property name="string2" type="string"> <column name="string2" length="255" /> </property> <property name="string3" type="string"> <column name="string3" length="255" /> </property> [.. 10 strings] <property name="text1" type="string"> <column name="text1" length="60000" /> </property> <property name="text2" type="string"> <column name="text2" length="60000" /> </property> <property name="date1" type="timestamp"> <column name="date1" not-null="true"/> </property> <property name="date2" type="timestamp"> <column name="date2" not-null="true"/> </property> <property name="number1" type="double"> <column name="number1" /> </property> <property name="number2" type="double"> <column name="number2" /> </property> </class> </hibernate-mapping> 

Questions

• Is it acceptable to lose the activity stream on a XAR export ?
• Do we delete activity events when a document is deleted ?