Understanding Oracle Application Framework (OAF)

Introduction

Oracle Application Framework (OAF) is Oracle's proprietary technology for building web-based application pages within the Oracle E-Business Suite environment. It provides developers with a structured, Java-based framework for creating interactive and data-driven web applications.

What is OAF?

OAF stands for Oracle Application Framework. It is a Java framework built on the J2EE MVC (Model-View-Controller) architectural pattern. This framework enables developers to create, develop, and deploy web-based application pages that integrate seamlessly with Oracle E-Business Suite.

The three-tier web application architecture of OAF separates concerns into three distinct layers, making development more organized, maintainable, and scalable.

The MVC Architecture in OAF

Model Layer

The Model layer is responsible for handling all business logic and data manipulation. In OAF, this layer is comprised of BC4J (Business Components for Java) components, which include:

Component	Full Name	Description
EO	Entity Object	Encapsulates business rules associated with a row in a database table
VO	View Object	Provides a way to work with data from Entity Objects or custom SQL queries
AM	Application Module	Container that manages access to BC4J model objects
VL	View Link	Defines relationships between View Objects
AO	Association Object	Defines relationships between Entity Objects

View Layer

The View layer handles the user interface and presentation logic. It determines how data is displayed to the user and how users interact with the application pages.

Controller Layer

The Controller layer manages user interactions and application flow. When a controller is created, a Java class file is generated. This layer is where developers write business logic, implement validations, and control navigation between pages.

Detailed Component Overview

Entity Object (EO)

The Entity Object encapsulates business rules associated with a specific row in a database table. Key characteristics include:

Direct Database Link: Entity Objects have a direct relationship with database tables
Data Interaction: The application interacts with the database through Entity Objects
Business Logic: EO contains validation rules and business logic at the data level
Reusability: Multiple View Objects can reference the same Entity Object

Example Use Case: An EO for the EMPLOYEES table would contain validation rules ensuring that salary values are within acceptable ranges and that department IDs reference valid departments.

View Object (VO)

The View Object helps the application work with Entity Objects and retrieve data. Key features include:

Flexibility: View Objects can be based on Entity Objects or independent SQL queries
Query Capability: VO may execute custom SQL queries with no direct relation to Entity Objects
Data Presentation: Provides the data structure needed for display in the user interface
Filtering and Sorting: Supports dynamic filtering and sorting of data

Example Use Case: A VO could be created to display employee details joined with department information, even if those tables are represented by separate Entity Objects.

Application Module (AM)

The Application Module serves as a container that provides and manages access to BC4J model objects. Critical points include:

Container Role: AM acts as the root container for all model objects on a page
Access Control: Provides controlled access to View Objects and Entity Objects
Page Control: Has complete control over the application page's functionality
Mandatory Component: An OAF page cannot run without an Application Module
Object Access: No object on a page can be accessed without going through the AM

Important: The Application Module is essential—without it, no OAF page can function.

Controller (CO)

The Controller responds to user actions and maintains application flow. It consists of two primary blocks:

Process Request

The Process Request block executes when the page loads. Use this block for:

Initializing default values when the page first loads
Setting up page-level variables
Performing initial data validation
Preparing data for display

Process Form Request

The Process Form Request block executes when the user performs an action, such as pressing a button. Use this block for:

Handling button clicks and form submissions
Executing business logic after user input
Performing validations on user-entered data
Controlling navigation after form submission

How OAF Components Work Together

The following illustrates how the components interact:

User Requests a Page: The user navigates to an OAF page
Controller - Process Request: The controller's Process Request block executes
Model Interaction: The Application Module provides access to View Objects
Data Retrieval: View Objects fetch data from Entity Objects or SQL queries
View Rendering: The View layer renders the page with retrieved data
User Interaction: The user interacts with the page (clicks buttons, submits forms)
Controller - Process Form Request: The Process Form Request block handles the action
Business Logic Execution: The controller executes validation and business logic
Navigation: Based on the outcome, the controller controls navigation

Key Benefits of OAF

Benefit	Description
Structured Development	MVC architecture provides clear separation of concerns
Reusability	Components can be reused across multiple pages
Integration	Seamless integration with Oracle E-Business Suite
Scalability	J2EE-based architecture supports enterprise-scale applications
Maintainability	Clear separation of business logic, presentation, and control
Declarative Development	Many features can be implemented without extensive coding

Summary

Oracle Application Framework (OAF) is a powerful Java-based framework for developing web applications within Oracle E-Business Suite. Built on the J2EE MVC pattern, OAF provides a structured approach to application development through:

Model Layer: BC4J components (EO, VO, AM, VL, AO) handling business logic and data
View Layer: Managing user interface and presentation
Controller Layer: Handling user interactions and application flow

The framework's component-based architecture, particularly the Application Module's role as a mandatory container and the Controller's dual-block structure (Process Request and Process Form Request), provides developers with a robust and flexible environment for building enterprise web applications.

Understanding these core concepts is essential for any developer working with Oracle E-Business Suite, as OAF remains the primary technology for creating custom pages and extending standard Oracle Applications functionality.

Oracle Apps/DBA

Pages

1. OA Framework Introduction