Chapter 8: Oracle Application Server Portal - Architecture

Oracle defines Oracle Application Server Portal as a rich, declarative environment for creating a portal web interface, publishing and managing information, accessing dynamic data, and customizing the portal experience, with an extensible framework for J2EE-based application access. While that one- sentence summarization is quite a mouthful, it does not do Oracle Application Server Portal justice . Oracle Application Server Portal is an incredibly powerful environment that allows developers to create and test sophisticated applications, all while writing and maintaining a very small amount of code. Like any truly powerful development environment, Oracle Application Server Portal can be used in a multitude of ways. For example, beginning developers can use Oracle Application Server Portal s wizards to generate applications consisting of forms, reports , and graphs and deploy those Oracle Application Server components quickly, easily, and with a minimum of coding. Advanced developers can enhance the generated components through the use of the Oracle Application Server Portal Application Programming Interface (API) or even bypass the wizards altogether and use Java and/or PL/SQL to create Oracle Application Server Portal portlets. The portal you create can pull data from a single database, multiple databases (including non-Oracle databases), and even from other sites on the Web. Oracle Application Server Portal can be used to create portlets that interact with other sites on the Web and use their content in your portal.

Oracle Application Server Portal leverages the open standards, enabling developers to build Java 2 Platform, Enterprise Edition/eXtensible Markup Language (J2EE/XML) components that can be exposed within the framework as pure HTML. With the introduction of Web Services for Remote Portals (WSRP) and Java Specification Request (JSR) 168, Oracle Application Server Portal support will include the capability to build interoperable applications that can be deployed across multiple vendor platforms. Furthermore, since Oracle Application Server Portal is a component of the Oracle Application Server, it can integrate with other components such as Oracle Application Server Discoverer and Oracle Application Server Reports to expose rich Business Intelligence Reports. As part of the Oracle Application Server, Oracle Application Server Portal can also be deployed in a number of different architectures to support scalability and high-availability scenarios.

What is a Portlet?

Oracle s definition is that they re reusable building blocks for easily publishing information and applications. You can think of a portlet as a small application that performs a specific function. Portlets are then placed and arranged on a page so that the end user can interact with them. Portlets can be forms, reports, graphs, links to other web sites, ad hoc query tools ”the list goes on and on (we ll explore the different types of portlets in Chapter 9). All portlets come from a data source registered within Oracle Application Server Portal, called a portlet provider. You can publish pages, navigation pages, and other Oracle Application Server Portal components as portlets, or use Oracle Application Server Portal s wizards to easily create reports, forms, charts , and other types of dynamic components. You can also build components with your own tools and integrate them through Oracle Application Server Portal s APIs, available in the Portal Developer Kit (PDK).

One of the most difficult, yet ultimately beneficial, concepts for many beginning Oracle Application Server Portal developers to grasp is the fact that the Oracle Application Server Portal development environment is itself an Oracle Application Server Portal application. All forms, pages, and wizards that developers use to generate Oracle Application Server Portal components are Oracle Application Server Portal elements themselves , stored in the Oracle Application Server Portal repository. This is beneficial to developers because they can work with a well-designed portal environment and understand the basics of Oracle Application Server Portal development, architecture, and navigation before attempting to build and deploy their first portal.

This chapter is designed to show the architecture of Oracle Application Server Portal and to provide a roadmap so that developers and administrators can find their way around Oracle Application Server Portal quickly. Subsequent chapters in this section will explore such topics as Oracle Application Server Portal development, administration, and incorporating Forms, Reports, and Discoverer into Oracle Application Server Portal. Even though Oracle Application Server Portal is a true declarative development environment that requires little, if any, coding for a complete application, it is still beneficial to define and explore the structure of Oracle Application Server Portal and how applications and portals are constructed . Given Oracle Application Server Portal is a true web-based development environment, you are probably anxious to jump in and start creating Oracle Application Server Portal portlets and applications immediately; some of the material in this chapter may appear dry in that context, but mastering the basics of Oracle Application Server Portal navigation will save you much time as your development efforts move forward.