Lecture Building reliable component-based systems - Chapter 7: Role-based component engineering. In this chapter, the following content will be discussed: Role-based components, motivating the use of roles, role technology, frameworks and roles. | Chapter 7 Role-Based Component Engineering Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering Overview Role-based components Motivating the use of roles Role technology Frameworks and roles Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering Role-based Components Focusing on the following aspects of object-oriented components: The interface The size or granularity Encapsulation Composition mechanisms Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering Components The interface of a component defines the syntax of how to use a component. The semantics of the interface are usually implicit. Reusability Plug-ability Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering Concept of Roles Components may have several different uses in a system that are dependent on the different roles a component can play in the . | Chapter 7 Role-Based Component Engineering Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering Overview Role-based components Motivating the use of roles Role technology Frameworks and roles Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering Role-based Components Focusing on the following aspects of object-oriented components: The interface The size or granularity Encapsulation Composition mechanisms Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering Components The interface of a component defines the syntax of how to use a component. The semantics of the interface are usually implicit. Reusability Plug-ability Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering Concept of Roles Components may have several different uses in a system that are dependent on the different roles a component can play in the various component collaborations in the system. With role-based components is that the public interface is separated into smaller interfaces, which model these different roles. Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering Kemerer and Chidamber’s Six Metrics WMC: Weighted Methods per Class DIT: Depth of Inheritance Tree NOC: Number Of Children CBO: Coupling Between Object classes RFC: Response For a Class LCOM: Lack of COhesiveness in Methods Page Building Reliable Component-based Systems Chapter 7 - Role-Based Component Engineering WMC - Weighted Methods per Class In terms of classes: This metric reflects the notion that a complex class has a larger influence on its subclasses than a small class. In terms of roles: Roles model only a small part of a class interface. The amount of WMC of a role is typically less than that of a class. Components are accessed using the role interfaces. A smaller part of the interface must be understood
