| Oracle® Application Development Framework Developer's Guide For Forms/4GL Developers 10g (10.1.3.1.0) Part Number B25947-01 |
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| Oracle® Application Development Framework Developer's Guide For Forms/4GL Developers 10g (10.1.3.1.0) Part Number B25947-01 |
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View PDF |
In line with community best practices, applications you build using Oracle ADF achieve a clean separation of business logic, page navigation, and user interface by adhering to a model, view, controller architecture. As shown in Figure 1-1, in an MVC architecture:
The model layer represents the data values related to the current page
The view layer contains the UI pages used to view/modify that data
The controller layer processes user input and determines page navigation
The business service layer handles data access and encapsulates business logic
Figure 1-2 illustrates where each ADF module fits in this architecture. The core module in the framework is Oracle ADF Model, a declarative data binding facility that implements the JSR-227 specification. The Oracle ADF Model layer enables a unified approach to bind any user interface to any business service with no code. The other modules Oracle ADF comprises are:
Oracle ADF Business Components, which simplifies building business services for developers familiar with 4GL tools like Oracle Forms, PeopleTools, SiebelTools, Visual Studio, and others
Oracle ADF Faces, which offers a rich library of UI components for web applications built with JavaServer Faces (JSF)
Oracle ADF Swing, which extends Oracle ADF Model to desktop applications built with Swing
Oracle ADF Controller, which integrates Struts and JSF with Oracle ADF Model
In the view layer of your application, where you design the web user interface, you can develop using either classic JavaServer Pages (JSP) or the latest JavaServer Faces (JSF) standard. Alternatively, you can choose the polish and interactivity of a desktop UI, and develop using any off-the-shelf Swing components or libraries to ensure just the look and feel you need. Whatever your choice, you work with WYSIWYG visual designers and drag-and-drop data binding. One compelling reason to choose JSF is the comprehensive library of nearly one hundred JSF components that the ADF Faces module provides.
ADF Faces components include sophisticated features like look and feel "skinning" and the ability to incrementally update only the bits of the page that have changed using the latest AJAX programming techniques. The component library supports multiple JSF render kits to allow interfacing with web browsers and PDA telnet devices. In short, these components dramatically simplify building highly attractive and functional web and wireless UIs without getting your hands "dirty" with HTML and JavaScript.
In the controller layer, where handling page flow of your web applications is a key concern, Oracle ADF integrates both with the popular Apache Struts framework and the built-in page navigation functionality included in JSF. In either case, JDeveloper offers visual page flow diagrammers to design your page flow, and the ADF Controller module provides appropriate plug-ins to integrate the ADF Model data binding facility with the controller layer's page processing lifecycle.
In the model layer, Oracle ADF Model implements the JSR-227 service abstraction called the data control and provides out-of-box data control implementations for the most common business service technologies. Whichever ones you employ, JDeveloper and Oracle ADF work together to provide you a declarative, drag-and-drop data binding experience as you build your user interfaces. Supported technologies include:
ADF application modules
These service components expose an updateable dataset of SQL query results with automatic business rules enforcement.
Web Services
When the services your application requires expose standard web services interfaces, just supply Oracle ADF with the URL to the relevant Web Services Description Language (WSDL) for the service endpoints and begin building user interfaces that interact with them and present their results.
XML
If your application needs to interact with XML or comma-separated values (CSV) data that is not exposed as a web service, you need only supply the provider URL and optional parameters and you can work with the data.
JavaBeans and Enterprise JavaBeans (EJB) Session Beans
When necessary, you can easily work with any Java-based service classes as well, including EJBs that support transactions.
For enterprise 4GL developers building new web applications, Oracle recommends using JavaServer Faces for the view and controller layers, and ADF Business Components for the business service implementation. This combination offers you the same productive J2EE technology stack that over 4000 of Oracle's own enterprise 4GL developers use every day to build the Oracle E-Business Suite. Since its initial release in 1999, several thousand external customers and partners have built and deployed successful Oracle ADF-based applications as well. Both now and in the future, Oracle and others are betting their business on Oracle ADF with ADF Business Components.
