Oracle Application Server 10g Essentials

Portlets

We introduced the concept of a portlet in the previous section. Basically, a portlet is a reusable program that delivers information. This information can come from a variety of sources. A portlet works with and leverages the services provided by the OracleAS Portal runtime to integrate its information into the overall OracleAS Portal environment. The portlet is one of the key enablers for OracleAS Portal’s display of information.

A portlet displays information that is collected from a source, known as a portlet provider . The portlet provider collects the information and then passes it to the portlet, which displays the information. This architecture, and the two types of portlet providers, are shown in Figure 13-3.

Figure 13-3. Portlet architecture and provider types

A portlet provider can provide information to many different portlets. Portlet providers can be organized into Provider Groups, which combine related providers. A Database Provider, described later, can be shared between multiple instances of OracleAS Portal.

Each portlet is registered in the Portlet Repository, which is a part of the overall OracleAS Infrastructure. When you build a page, you can select any of the portlets in the repository for inclusion in a region.

An individual instance of a portlet can be shared across multiple pages in a page group. By sharing a portlet, you both ensure a consistent view ...