Object Libraries

Object libraries are convenient holds of objects for reuse. They support project, corporate, and personal standards and they simplify reuse in complex environments.

An object library can hold simple objects, object groups, property classes and program units, but they are protected against modify in the library. An Objects can be used as standards classes) for other objects.

An Object library simplifies the sharing of reusable components. Reusing elements enables you to:

•    Apply standards to simple objects, like as items and buttons, for a consistent look and feel
•    Reuse complex objects like a Navigator

In combination with SmartClasses, that are discussed later, object libraries support both of these needs.

Note: Form Builder opens all libraries which were open when you last closed Form Builder

Why Object Libraries Instead of Object Groups?

•    Object libraries can hold individual items; for instance, iconic buttons. The smallest unit accepted in an object group is a block.
•    An Object libraries accept PL/SQL program units.
•    If you modify an object in an object library, all forms which hold the subclassed object reflect the modification.

Creating an Object Group

An object group is a logical container for a group of Form Builder objects.
You describe an object group when you need to package associated objects for copying or subclassing in another module. You could use object groups to bundle numerous objects into higher-level building blocks which you can use again in another application.
 
SmartClass

A SmartClass is a special member of an Object Library. As like other Object Library members, it could be used to subclass existing objects in a form using a SmartClass option from the right mouse button popup menu. An Object Library member that is not SmartClasses can only be used to create new objects in form modules into that they are added.

If you often use certain objects as standards, like as standard buttons, alerts and date items, you can mark them as SmartClasses through selecting each object in the object library and selecting

Object→SmartClass.

You  can  mark  several  different  objects  which  are  spread  across  multiple  object  libraries  as SmartClasses.
You can also have several SmartClasses of a provided object type; for instance:

•    Wide_Button
•    Narrow_Button
•    Small_Iconic_Button
•    Large_Iconic_Button

Work with SmartClasses

1.Select an object in the Navigator or Layout Editor.
2.From the pop-up menu, select SmartClasses. A SmartClasses pop-up menu lists all the SmartClasses from all open object libraries which have the similar type as the object. Whenever you select a class for the object, it will become the parent class of the object. You could see its details in the Subclass Information dialog box, now like any other subclassed object.

This mechanism makes it extremely simple to apply classes to existing objects.