After deploying you find the configuration.xml file in webapps/portal/WEB-INF/conf Use component registration tags. Let's look at the key tag that defines the interface and the type tag that defines the implementation. Note that the key tag is not mandatory, but it improves performance.

<!-- Portlet container hooks -->

  <component>

    <key>org.exoplatform.services.portletcontainer.persistence.PortletPreferencesPersister</key>

    <type>org.exoplatform.services.portal.impl.PortletPreferencesPersisterImpl</type>

  </component>

Register plugins that can act as listeners or external plugin to bundle some plugin classes in other jar modules. The usual example is the hibernate service to which we can add hbm mapping files even if those are deployed in an other maven artifact.

<external-component-plugins>

  <target-component>org.exoplatform.services.database.HibernateService</target-component>

  <component-plugin> 

    <name>add.hibernate.mapping</name>

    <set-method>addPlugin</set-method>

    <type>org.exoplatform.services.database.impl.AddHibernateMappingPlugin</type>

    <init-params>

      <values-param>

        <name>hibernate.mapping</name>

        <value>org/exoplatform/services/portal/impl/PortalConfigData.hbm.xml</value>

        <value>org/exoplatform/services/portal/impl/PageData.hbm.xml</value>

        <value>org/exoplatform/services/portal/impl/NodeNavigationData.hbm.xml</value>

      </values-param>        

    </init-params>

  </component-plugin>

</external-component-plugins>

In that sample we target the HibernateService and we will call its addPlugin() method with an argument of the type AddHibernateMappingPlugin. That object will first have been filled with the init parameters.

Therefore, it is possible to define services that will be able to receive plugins without implementing any framework interface.

Another example of use is the case of listeners as in the following code where a listener is added to the OrganisationService and will be called each time a new user is created:

<external-component-plugins>

  <target-component>org.exoplatform.services.organization.OrganizationService</target-component>

  <component-plugin>

    <name>portal.new.user.event.listener</name>

    <set-method>addListenerPlugin</set-method>

    <type>org.exoplatform.services.portal.impl.PortalUserEventListenerImpl</type>

    <description>this listener create the portal configuration for the new user</description>

    <init-params>

      <object-param>

        <name>configuration</name>

        <description>description</description>

        <object type="org.exoplatform.services.portal.impl.NewPortalConfig">

          <field  name="predefinedUser">

            <collection type="java.util.HashSet">

              <value><string>admin</string></value>

              <value><string>exo</string></value>

              <value><string>company</string></value>

              <value><string>community</string></value>

              <value><string>portal</string></value>

              <value><string>exotest</string></value>

            </collection>

          </field>

          <field  name="templateUser"><string>template</string></field>

          <field  name="templateLocation"><string>war:/conf/users</string></field>

        </object>

      </object-param>

    </init-params>

  </component-plugin>

...

In the previous XML configuration, we refer the organization service and we will call its method addListenerPlugin with an object of type PortalUserEventListenerImpl. Each time a new user will be created (apart the predefined ones in the list above) methods of the PortalUserEventListenerImpl will be called by the service.

As you can see, there are several types of init parameters, from a simple value param which binds a key with a value to a more complex object mapping that fills a JavaBean with the info defined in the XML.

Many other examples exist such as for the Scheduler Service where you can add a job with a simple XML configuration or the JCR Service where you can add a NodeType from your own configuration.xml file.