A portlet deployed on ATG Portal is packaged as a separate J2EE Web application and includes a Web application deployment descriptor file (web.xml). The Portlet Deployment Tool automatically generates the Web application, including the deployment descriptor file. Note the following elements in the Helloworld portlet deployment descriptor file, which is located at <ATG11dir>/Portlet/helloworld/helloworld/helloworld/WEB-INF/web.xml. These elements are added automatically by the Portal Deployment Tool.

DynamoServerPageFilter

This element of the deployment descriptor file invokes the DAF servlet pipeline. The DAF servlet pipeline (described in the Request Handling with Servlet Pipelines chapter of the Platform Programming Guide) is a series of request-handling servlets. If the current request has not already started the DAF servlet pipeline, the DynamoServerPageFilter routes the request to the servlet pipeline.

<filter>
  <filter-name>DynamoServerPageFilter</filter-name>
  <display-name>DynamoServerPageFilter</display-name>
  <description>This filter invokes the dynamo application framework servlet
pipeline.</description>
  <filter-class>atg.filter.dspjsp.PageFilter</filter-class>
  </filter>

NucleusServlet

This element starts Nucleus, if Nucleus has not already been started. The NucleusServlet creates an instance of Nucleus and sets it as an attribute of the Web application, making Nucleus services available.

<servlet>
  <servlet-name>NucleusServlet</servlet-name>
  <display-name>NucleusServlet</display-name>
  <description>Initializes nucleus in the current web application.</description>
  <servlet-class>atg.nucleus.servlet.NucleusServlet</servlet-class>
  <load-on-startup>1</load-on-startup>
</servlet>

Taglibs

In addition, you may want to add elements like these, which make available the ATG dspjsp and dspjspEL taglibs, as well as the Java portlet taglib. These are standard tag libraries that may be valuable in portlet JSPs:

<taglib>
    <taglib-uri>dsp</taglib-uri>
    <taglib-location>/WEB-INF/tld/dspjspTaglib1_0.tld</taglib-location>
</taglib>
<taglib>
    <taglib-uri>atg-dspjspEL</taglib-uri>
    <taglib-location>/WEB-INF/tld/dspjspELTaglib1_0.tld</taglib-location>
</taglib>
<taglib>
    <taglib-uri>http://java.sun.com/portlet</taglib-uri>
    <taglib-location>/WEB-INF/tld/portlet.tld</taglib-location>
</taglib>