Design pattern (computer science)
Design patterns are recurring solutions to problems in object-oriented design. The phrase was introduced to computer science in the 1990s by the text Design Patterns: elements of reusable object-oriented software. The scope of the term remained a matter of dispute into the next decade. Algorithms are not thought of as design patterns, since they solve implementation problems rather than design ones. Typically, a design pattern is thought to encompass a tight interaction of a few classes and objects.
Professor Christopher Alexander's work on a pattern language, for designing buildings and communities, was the inspiration for the design patterns of software.
Interest in sharing patterns in the software community has led to a number of books, symposiums, and the formation of Ward Cunningham's original wiki. The goal of pattern literature is to make the experience of past designers accessible to beginners and others in the field. A book of design patterns presents different solutions in a common format, to provide a language for discussing design issues.
Pattern Format
The design pattern format has four essential parts, although names and ordering differ by source:
Name
Every pattern needs a name, to provide a language for design discussion.
Problem
Recurring circumstances lead to the discovery of this pattern by multiple persons. A primary goal of design is to limit the amount of source change needed to change a program's observed behavior, but this can be difficult to achieve if a designer does not understand the implications of a design.
Solution
The solution is described sufficiently for implementation by novices, although the implementation is usually given in general enough terms that it can be adapted to different projects.
Consequences
Applying this solution will effect the rest of the project in certain ways, so it is important to mention any common negative or serendipitous side-effects.
Similar Terms
Poor (yet unfortunately common) solutions to common problems are sometimes known as anti-patterns.
See also amelioration pattern
A List of Design Patterns
Fundamental patterns
Creational patterns
Structural patterns
Behavioral patterns
RealTime patterns
Related Topics
References
- Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides: Design Patterns, Addison-Wesley, 1995, hardcover, 395 pages, ISBN 0201633612, Design Patterns CD, 1997 ISBN 0201634988
- Frank Buschmann, Regine Meunier, Hans Rohnert, Peter Sommerlad, Michael Stal: Pattern-oriented Software Architecture, Volume 1: A System of Patterns, John Wiley & Sons Ltd., ISBN 0471958697
- Douglas Schmidt: Pattern-oriented Software Architecture. Volume 2: Patterns for Concurrent and Networked Objects, John Wiley & Sons Ltd., ISBN 0471606952
- Alan Shalloway, James R. Trott: Design Patterns Explained: A New Perspective on Object-Oriented Design, Addison-Wesley, ISBN 0201715945
- Martin Fowler: Patterns of Enterprise Application Architecture, Addison-Wesley, ISBN 0321127420
External links
Referenced By
Adapt to adapt | Comp.sc. | Computer Science | Computer Sciences | Computer Scientists | Computer scientist | Computing science | Delegation pattern | Design Pattern | Design pattern (disambiguation) | Design patterns | List of basic software engineering topics | List of important publications in computer science | List of software engineering topics | Model-view-controller | Model/View/Controller | Model view controller | Pattern | Persistence | Programmer's practice | Programming practice | Software Engineer | Software Engineering | Software Hut | Software design
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