CSC/ECE 517 Fall 2009/wiki3 ksm 6

Introduction

A programmer, at the time of designing, usually is concerned about their behavior. But other aspects such as the availability of a particular object at the time when it is required also need to be considered. The rules of creation should be followed. Sometimes, the developers intermix the management of object creation with object instantiation. Using same code for object creation as well as object instantiation, can lead to complexity of code. It has to keep a track of object creation, construction parameters, as well as the use of those objects after creation. This leads to several consequences such as reducing coupling as well as selection of an instantiation scheme early. To address these issues, Factories are used which help to keep the objects cohesive, testable and decoupled. The design becomes flexible and the problem can be split into chunks of manageable pieces.

Overview

In this article,we are going to discuss about Factory method Pattern. We will first look at the objectives of creational patterns. Then we will have a look at different creational patterns. We will try to find out how and why the Factory Method Pattern has an edge over other creational patterns. How Factory method design pattern is implemented in some Object Oriented languages. Finally we will discuss about the uses as well as the contribution of Factory pattern in providing an elegant solution to a problem.

Features

The Gang of Four describes the Factories as creational patterns and their general classification is:

• Abstract Factory Pattern

• The Builder Pattern

• The Factory Method Pattern

• The Prototype Pattern

• The Singleton Pattern

These general classifications are based on three broad classifications:

• Behavioral Pattern - used to contain variation of behavior.

• Structural Pattern - used to integrate an existing code into new object-oriented design.

• Factory Pattern - used in the creation of objects.

Links

Factory method design pattern wikipedia

Advantages of Factory method

http://gsraj.tripod.com/design/creational/factory/factory.html

Referances

Design Patterns Explained: A New Perspective on Object-Oriented Design, Second Edition ,By: Alan Shalloway; James R. Trott. ISBN-978-0-321-24714-8 [[Image:]]