Tiles Definitions

A JSP template system uses one template for the layout and another for the fill-in components. Tiles calls these layout files “definitions”. To avoid creating an extra file just to specify the layout, Tiles allow the layout definitions to be stored as a JavaBean. For Service Provider, these definitions are declared in the following XML configuration files, located in the $WSHOME/WEB-INF/spe/config directory:

• tiles-page-defs.xml

• tiles-nav-defs.xml

• tiles-tab-defs.xml

These definitions files are specified in the deployment descriptor file, $WSHOME/WEB-INF/web.xml:

<init-param>
   <param-name>definitions-config</param-name>
   <param-value>/WEB-INF/spe/config/tiles-tab-defs.xml,
                /WEB-INF/spe/config/tiles-nav-defs.xml,
                /WEB-INF/spe/config/tiles-page-defs.xml</param-value>
</init-param>

The following example shows the base definition for a Service Provider page, as defined in tiles-page-defs.xml:

<definition name=".page.Base" path="spe/user/common/layouts/page.jsp"
      controllerClass="com.sun.idm.idmx.web.LocalizePageTitles">
   <put name="page_title_key" value="${page_title_key}" />
   <put name="masthead" value="spe/user/common/tiles/masthead.jsp" />
   <put name="navbar"   value="${navbar}" />
   <put name="left_nav" value="spe/user/common/tiles/left_nav.jsp" />
   <put name="content"  value="${content}" />
   <put name="footer"   value="spe/user/common/tiles/footer.jsp" />
</definition>

The attributes passed into this definition may consist of message resource bundle keys, like page_title_key, or references (directly or indirectly) to other tiles inserted on the page.

A tile definition may include a controller class. This class may access tile attributes from the context before the tile is rendered. In Service Provider, the controller class looks up the appropriate page title or subtitle from the message resource bundle based on the key passed as a tile attribute. The Struts framework uses a locale-specific resource bundle, if it exists.