For more efficient management of your applications, organize rules into classes. A class describes a collection of rules or other objects, such as properties, activities, and HTML forms, that are available to other, child classes, or to instances of the class. Pega Platform organizes classes into a hierarchy, in which the system searches from the current class upwards when looking for a rule to apply.

Within an application, Pega Platform groups rules into classes according to their capacity for reuse. Each application consists of the following types of classes:

Work class

The Work class contains the rules that define the processing of cases, such as processes, data elements, and user interfaces.

Integration class

The Integration class contains the rules that define interactions between the application and other systems, such as an external database.

Data class

The Data class contains the rules that define the data objects that your application uses, such as customer information.

Because you can reuse rules between classes, you save time and reduce your development costs.

• Class layers

  Classes define the applicability, or scope, of a rule instance. Knowledge of the different layers of classes and their inheritance relationships is important as you develop applications.

• Understanding class hierarchy and inheritance

  To save development time when creating an application, reuse rules by organizing them into classes, and then creating dependencies between the classes. When you create a class hierarchy you define which classes contain other classes, and as a result, you define how classes reuse or inherit rules.

• External classes

  An external class is a concrete class (instance of the Rule-Obj-Class rule type) that corresponds to a table in an external relational database, rather than to a table or view in the PegaRULES database.

• Creating classes

  For improved development and maintenance of your application, organize the rules and other objects in your application into classes. By creating classes, you define collections of objects that are available to other classes or to instances of the class. You can reuse classes, and as a result reduce both development time and costs.

• General tab on the Class form

  Use the General tab to define the class inheritance and database access.

• Locking tab on the Class form

  Information on this tab is used only for concrete classes that do not belong to a class group.

• Advanced tab on the Class form

  The Advanced tab is only meaningful for concrete classes derived from the Rule-, Data-, or Work- class. Use the fields on this tab to control advanced settings such as class deprecation and ruleset restrictions.

• External Mapping tab on the Class form

  The External Mapping tab is used primarily for external classes. External classes are created by the Connector and Metadata wizard or the Database Class Mapping gadget and are linked by a Database Table data instance to a table in a database other than the PegaRULES database.

• About the Rename a Class wizard

  Use the Rename a Class wizard to rename a class and all of its pattern inheritance dependent classes. In addition you can choose to rename associated objects such as work- instances, properties, activities, and flows.

• About the Delete a Class wizard

  You can use the Delete a Class wizard to remove a class, all of its pattern- inheritance dependent classes and associated objects such as properties, activities, instances (including work items, attachments and assignments).

• Understanding class hierarchy and inheritance

• Organizing rules