Hook plugins are more powerful plugins that come to complement portlets, themes, layout templates, and web modules. A hook plugin is always combined with a portlet plugin. For instance, the
so-portlet project is a portlet plugin for Social Office with hooks.
In general, there are three kinds of hook parameters:
portal-properties (called portal properties hooks),
language-properties (called language properties hooks), and
custom-jsp-dir (called JSP hooks) as specified in
<!ELEMENT hook (portal-properties?, language-properties*, custom-jsp-dir?)>
As shown in the preceding code, the ordering of elements is significant in the DTD—you need to have your portal properties, ...