Chapter 4. The Structure of a Design Pattern
You may be curious about how a pattern author might approach outlining a structure, implementation, and purpose of a new pattern. A pattern is initially presented in the form of a rule that establishes a relationship between:
A context
A system of forces that arises in that context
A configuration that allows these forces to resolve themselves in context
With this in mind, lets now take a look at a summary of the component elements for a design pattern. A design pattern should have the following:
- Pattern name
- Description
- Context outline
The contexts in which the pattern is effective in responding to users’ needs.
- Problem statement
A statement of the problem being addressed so we can understand the intent of the pattern.
- Solution
A description of how the user’s problem is being solved in an understandable list of steps and perceptions.
- Design
A description of the pattern’s design and, in particular, the user’s behavior in interacting with it.
- Implementation
A guide to how the pattern would be implemented.
- Illustrations
Visual representations of classes in the pattern (e.g., a diagram).
- Examples
Implementations of the pattern in a minimal form.
- Corequisites
What other patterns may be needed to support use of the pattern being described?
- Relations
What patterns does this pattern resemble? Does it closely mimic any others?
- Known usage
Is the pattern being used in the wild? If so, where and how?
- Discussions
The team or author’s thoughts on the exciting benefits of the ...