Design Patterns: Factory

Questions and Answers

What is a primary concern when using the 'new' keyword in code?

It enhances code readability.

It enables dynamic behavior in classes.

It simplifies the object creation process.

It leads to concrete class dependencies. (correct)

What does the Factory Method Pattern allow subclasses to do?

Decide which object to instantiate. (correct)

Increase dependency on concrete classes.

Directly create multiple objects.

Override the parent class's methods.

Which principle suggests that high-level components should not depend on low-level components?

Dependency Injection Principle.

Dependency Inversion Principle. (correct)

Interface Segregation Principle.

Single Responsibility Principle.

What is the effect of using a static createPizza method in a pizza store?

It restricts flexibility in pizza type management. Signup and view all the answers

How does the SimplePizzaFactory approach address local variations in pizza making?

By allowing responsiveness to local demands. Signup and view all the answers

What is a significant limitation of the Simple Factory pattern mentioned?

It lacks abstraction in object creation. Signup and view all the answers

What design principle is emphasized by stating 'Depend upon abstractions'?

Using interfaces where possible. Signup and view all the answers

Why is the refactoring of the PizzaStore significant?

It isolates the pizza creation process. Signup and view all the answers

What does the term 'Families of Ingredients' refer to in the context of pizza making?

Diverse sources for pizza ingredients. Signup and view all the answers

What is an important goal when introducing an abstract PizzaStore?

To enable standardization across locations. Signup and view all the answers

Study Notes

Introduction to the "new" keyword reveals it creates concrete instances, making the code susceptible to modification.
Concept of encapsulating object creation is essential for better code maintenance.
SimplePizzaFactory provides a straightforward implementation for creating pizza objects without exposing the concrete classes directly.
Refactoring the PizzaStore facilitates improved organization and scalability of code.

Design Principles and Discussion

New pizza types can be added without altering existing code, showcasing extensibility of the design.
Discussion points include achievements made through this approach and considerations of using a static createPizza method, analyzing pros and cons along with UML representation.
Simple Factory, while beneficial, is not categorized as a GoF (Gang of Four) pattern; it remains a helpful concept nonetheless.

Franchising Pizza Stores

Different city locations introduce variations in pizza styles, necessitating a method to maintain local preferences and quality.
Implementation of a simple factory approach enables customization while ensuring product consistency.
Establishing an abstract PizzaStore allows subclasses to determine specific behaviors, enhancing flexibility in design.

Factory Method Pattern

The Factory Method Pattern centralizes object creation, allowing subclasses to dictate which objects to instantiate.
By deferring instantiation to subclasses, design promotes greater modularity and adherence to open/closed principle.
UML diagrams facilitate a visual understanding of the Factory Method concept and relationships between classes.

Dependency Inversion Principle

Key design principle emphasizes reliance on abstractions rather than concrete classes, termed the Dependency Inversion Principle (DIP).
High-level modules should not have dependencies on low-level modules; both should rely on shared abstractions to achieve better abstraction and flexibility in architecture.
Application of DIP in the pizza store scenario enhances maintainability and adaptability in handling new ingredient requirements.

Ingredient Consistency

To ensure uniformity in pizza quality, consideration of ingredient families leads to the demand for ingredient factories.
Reworking aspects of pizza creation and pizza store design can enhance alignment with desired quality standards.
Consistency in the selection of ingredients and preparation methods plays a pivotal role in the success of franchised operations.

Description

This quiz explores the Factory design pattern within software engineering, focusing on encapsulating object creation and enhancing the flexibility of code. We will discuss practical applications, challenges, and achievements related to the implementation of Factory patterns in pizza shops and beyond.