Technology Crunch

Business Components (continue) Creating Data Model Components: In this chapter you will learn how to expose data to a client application. ADF BC does not allow MVC applications to access entity object definitions and associations directly. Instead, you select exactly what data you want clients to be able to access by exposing it through data model components (view object definitions, view link definitions, application module definitions). The first part of this chapter shows how to create view object definitions and later in the chapter you will learn how to use view link definitions to represent relationships between your view object definitions and using application module definitions to aggregate the data and relationships that an application will need. Remember these facts about view object definitions: A view object definition is the representation of a SQL query. A view object definition includes view attributes for every column in the query result set...

Entity Object & Entity Classes in Detail Entity objects Business Rules: It can do more than just be representations of data. They can also encapsulate the business rules pertaining to the data they represent.  An entity object can:     Enforce validation rules for attribute values     Calculate default values for attributes     Automatically calculate the values of transient attributes    Automatically react to data changes    Overview of Entity Classes: Entity object definitions are handled by three classes in the ADF BC library. They are referred to as the base entity classes: oracle.jbo.server.EntityImpl  Each instance represents one row in a database table. This class has all the methods needed to read, update, insert, delete, and lock rows.  oracle.jbo.server.EntityDefImpl  Instances of this class act as wrappers for the entity object definition XML files.   The class cont...

ADF Business Components [Fundamentals] - My own understanding and View Introduction: ADF BC is a Java and XML based framework for developing the following : Business logic, including validation and default logic  Queries  Transaction handling Data access                It does not create a user interface, but is a pure encapsulation of business logic that communicates with a separate client application, which handles user interaction. Using ADF BC is the simplest way to design data-aware applications with JDeveloper.  The advantage of ADF BC over UI-enforced business logic is re-usability. For example, a single ADF BC layer can provide the business logic for all a company's needs. The business components can be used again and again, with multiple interfaces (a time saver). By maintaining a cache of data in memory, ADF BC reduces the number of database trips required by an application resulting in improved perfo...