DPML Metro: Parts Directive
Part Reference Directive

A <part> elements enables the declaration of a single nested component via specification of a part uri. During construction of a component, a classloader chain will be constructured using the enclosing classloader as an anchor and a chain definition based on the supplied part classpath definition.

Element Attributes
key A required key identifying the nested part.
uri A required artifact uri resolvable to a part datastructure.
Nested Elements
param 0..n a key/value binding used to construct a uri query argument.

The following XML fragment demonstrates a component directive containing a single nested part reference. The example demonstrates the declaration of a context entry query qualifier using a nested param value.

  <component xmlns="dpml:metro" name="demo" class="org.acme.Demo">
      <part key="widget" uri="link:part:org/acme/org-acme-widget">
        <param key="message" value="Hello"/>