View
877
Download
0
Category
Tags:
Preview:
DESCRIPTION
Factory Method Design Pattern Explained
Citation preview
Factory Method Pattern
Shahriar Iqbal Chowdhury & Monjurul Habib
Code Name: Remington
http://www.facebook.com/groups/netter/
Why We need Factory? Caveman Example
The Solution
A specialist for the job
Factory Pattern Method Basics
• Creational Pattern• Which object to create• It lets a class defer instantiation to subclasses.• Absolutely all constructors should be private or protected• Also known as Virtual Constructor.
When to consider?
• When we have a class that implements an interface but not sure which object, which concrete instantiation / implementation need to return.• When we need to separate instantiation from the representation.• When we have lots of select and switch statements for deciding which concrete class to create and return.
Factory Says
Define an interface for creating an object, but let subclasses decide which class to instantiate
Problem without Factory Method Pattern
Solution Applying Factory Method Pattern
Banking Account Management System
Object is created based on configuration parameters
Violation of OCP (Open Close Principle of SOLID)
we will need to create a property that indicates type in each account class
Recommended