# BIRT Chart Library Aggregate Function Extension

###### Identifier:

org.eclipse.birt.chart.engine.aggregatefunctions

###### Since:

1.0.0

###### Description:

This extension point is used to define custom Aggregate Functions for use by the chart library. Each extension must implment the IAggregateFunction interface.

###### Configuration Markup:

<!ELEMENT extension (aggregateFunction)>

<!ATTLIST extension

point CDATA #REQUIRED

id CDATA #IMPLIED

name CDATA #IMPLIED

>

<!ELEMENT aggregateFunction EMPTY>

<!ATTLIST aggregateFunction

name CDATA #REQUIRED

function CDATA #REQUIRED

displayName CDATA #IMPLIED

>

The definition of an Aggregate Function for use by the Chart Library.

- name - The name of the aggregate function.
- function - The class providing the evaluation services for this aggregate function. This class should the implement IAggregateFunction interface.
- displayName - The display name of the aggregate function.

###### Examples:

###### API Information:

The Aggregate Function implementation must implement the IAggregateFunction interface in the org.eclipse.birt.chart.aggregate package. See the javadoc for the interface for more information.

###### Supplied Implementation:

The org.eclipse.birt.chart.engine.extension plug-in provides an example of an implementation of IAggregateFuntion.

Copyright (c) 2004-2005 Actuate Corporation. All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse Public License v2.0 which accompanies this distribution, and is available at http://www.eclipse.org/legal/epl-2.0.html