DPML Metro Component Task

Part XML Directive

A part content datatype is an XML document that defines an information block, an object deployment strategy, and a classloader chain. The information block declares a title and a description. The deployment strategy is defined as any element extending the StrategyType schema definition (the most typical being the Metro component strategy). The third element in a part definition is a deployment classpath which is composed of a public, protected, and private classloader definitions that are used to establish a classloader chain relative to the current context classloader.

Namespace

dpml:part

Description

A part defines a general deployment unit.

The part specification contains a general <info> block, a deployment <strategy> specification and a <classpath> definition.

Nested Elements

`info`	The info definition is used to associate a title and human readable description.
`strategy`	Any XML element derived from the `StrategyType`. The schema element defines the deployment strategy. A part strategy handler is resolved by the part content handler. If the qualfied element name is recognized an internal handler is assigned, otherwise value of the `handler` attribute is used to resolve a uri identifying a strategy plugin. The Metro system provides two bundled strategy element handlers - `<component>` and `<resource>`. The `<resource>` handler provides support for Antlib loading, and the `<component>` strategy details the standard Metro component deployment model.
`classpath`	Definition of the classpath for the part. The classpath contains the declaration of public, protected and private jar files referenced via uris that collectively enable the construction of a cloassloader chain.

Examples

Example part definition:

<?xml version="1.0"?>

<part xmlns="dpml:part">

  <info/>

  <component xmlns="dpml:metro" 
    class="org.acme.Widget"/>

  <classpath>
    <private>
      <uri>artifact:jar:acme/widget/acme-widget#1.2.3</uri>
    </private>
  </classpath>

</part>