GoF Design Patterns Template

Posted by admin on August 1, 2009 under Software Architect | Be the First to Comment

The GoF design patterns are in the middle of these levels of abstraction

A design pattern names, abstracts, and identifies key aspects of a common design structure that makes it useful for creating a reusable object-oriented design.

The GoF design patterns are

descriptions of communicating objects and classes that are customized to solve a general design problem in a particular context.

GoF Classification Of Design Patterns

Purpose- what a pattern does

1. Behavioral Patterns – Deal with the interaction of classes and objects
2. Creational Patterns – Concern the process of object creation
3. Structural Patterns – Deal with the composition of classes and objects

Scope- what the pattern applies to

Class Patterns

• Focus on the relationships between classes and their subclasses
• Involve inheritance reuse

Object Patterns

• Focus on the relationships between objects
• Involve composition reuse

GoF Essential Elements Of Design Patterns

Pattern Name

• Having a concise, meaningful name for a pattern improves communication among developers

Problem

• What is the problem and context where we would use this pattern?
• What are the conditions that must be met before this pattern should be used?

Solution

• A description of the elements that make up the design pattern
• Emphasizes their relationships, responsibilities and collaborations
• Not a concrete design or implementation; rather an abstract description

Consequences

• The pros and cons of using the pattern
• Includes impacts on reusability, portability, extensibility

GoF Pattern Template

Pattern Name and Classification	A good , concise name for the pattern and the pattern’s type
Intent	Short statement about what the pattern does
Also Known As	Other names for the pattern
Motivation	A scenario that illustrates where the pattern would be useful
Applicability	Situations where the pattern can be used
Structure	A graphical representation of the pattern
Participants	The classes and objects participating in the pattern
Collaborations	How to do the participants interact to carry out their responsibilities?
Consequences	What are the pros and cons of using the pattern?
Implementation	Hints and techniques for implementing the pattern
Sample Code	Code fragments for a sample implementation
Known Uses	Examples of the pattern in real systems
Related Patterns	Other patterns that are closely related to the pattern

References: Prof. Bob Tarr's Notes