Creational Patterns

• Creational Design Patterns (Objects)

These patterns deal with the process of objects created in such a way that they can be decoupled from their implementing system. This provides more flexibility in deciding which objects need to be created for a given use case/ scenario. There are as follows:

1. Factory Method

• Creates an instance of several derived classes

• Design pattern defines an interface for creating an object, but let subclasses decide which class to instantiate. This pattern lets a class defer instantiation to subclasses.

• The factory design pattern is used to replace the class constructors, abstracting the process of object generation so that the type of the object instantiated can be determined at run-time

• Subclasses figure out what objects should be created.

• Parent class allows later instantiation to subclasses means the creation of an object is done when it is required.

• The process of objects created is required to centralize within the application.

• A class (creator) will not know what classes it will be required to create.

• (Tr) Bu tasarım deseni, nesne yaratımını kalıtım yoluyla alt sınıflara bırakarak, client tarafında nesne yaratımını engeller.

2. Abstract Factory

• Creates an instance of several families of classes

• The design pattern provides an interface for creating families of related or dependent objects without specifying their concrete classes

• Create a set of related objects or dependent objects which must be used together.

• System should be configured to work with multiple families of products.

• The creation of objects should be independent of the utilizing system.

• Concrete classes should be decoupled from clients.

• (Tr) Bu tasarım deseni, ortak bir teması olan bir grup bireysel fabrikayı somut sınıflarını belirtmeden encapsulate etmek için bir yol sağlar.

3. Builder

• Separates object construction from its representation

• The pattern separates the construction of a complex object from its representation so that the same construction process can create different representations.

• Need to create an object in several steps (a step by step approach).

• The creation of objects should be independent of the way the object's parts are assembled.

• Runtime control over the creation process is required.

• (Tr) Bu tasarım deseni, karmaşık bir nesnenin yapımını temsilinden ayırır, böylece programın ihtiyaçlarına bağlı olarak birkaç farklı temsil oluşturulabilir.