/
Introduction to software design patterns Introduction to software design patterns

Introduction to software design patterns - PowerPoint Presentation

alexa-scheidler
alexa-scheidler . @alexa-scheidler
Follow
435 views
Uploaded On 2015-09-21

Introduction to software design patterns - PPT Presentation

For CSE 3902 By Matt Boggus Why Design Objects and Systems Processes httpipostrcompic275Planning Patterns Each pattern describes a problem which occurs over and over again in our environment and then describes the core of the solution to that problem in such a way that you ca ID: 135554

pattern design problem patterns design pattern patterns problem elements solution object oriented http describes uml wiki description classes reusable

Share:

Link:

Embed:

Download Presentation from below link

Download Presentation The PPT/PDF document "Introduction to software design patterns" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.


Presentation Transcript

Slide1

Introduction to software design patterns

For CSE 3902

By: Matt

BoggusSlide2

Why Design?

Objects and Systems

Processes

http://ipostr.com/pic-275-PlanningSlide3

Patterns

“Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice”

Christopher AlexanderSlide4

Design Pattern

“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.”

Gang of Four (Design Patterns: Elements of Reusable Object-Oriented Software)Slide5

Why use design patterns?

Solve commonly occurring problems using existing well known and tested approaches

More efficient communication

"Let's

use an ADAPTER.

“ compared to…"How about a superclass with a

getTemperature method and then subclass that with classes that reference instances of the vendor-supplied classes for...."Slide6

Four essential elements to a Pattern

Pattern

Name

Having

a concise, meaningful name for a pattern improves communication among

developersProblemWhat

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, extensibilitySlide7

UML Notation

Design patterns in UML paper

http://en.wikipedia.org/wiki/File:Command_Design_Pattern_Class_Diagram.pngSlide8

Downsides

Many design patterns only make sense in an object oriented system

Do not use a pattern just because you can

http://c2.com/cgi/wiki?GoldenHammer

Avoid

anti-patterns!