Single Responsibility Principle (SRP)
This principle states that each class should have a single responsibility. It emphasizes that a class should perform one specific function and not have too many reasons to change.
Example: Managing user information and sending email notifications.
class UserManager def create_user(user_data) # Logic for creating a user end end class EmailService def send_email(email_data) # Logic for sending an email end end
Open/Closed Principle (OCP)
This principle encourages extending functionality by adding new code rather than modifying existing code.
Example: Handling different payment methods in an e-commerce application.
class PaymentProcessor def process_payment # Common logic for payment processing end end class CreditCardPaymentProcessor < PaymentProcessor def process_payment # Logic for processing credit card payment end end class PayPalPaymentProcessor < PaymentProcessor def process_payment # Logic for processing PayPal payment end end
Liskov Substitution Principle (LSP)
This principle asserts that objects of a derived class should be substitutable for objects of the base class without affecting the correctness of the program.
Example: Managing geometric shapes.
class Shape def area # Common logic for calculating area end end class Rectangle < Shape def area # Logic for calculating area of rectangle end end class Square < Shape def area # Logic for calculating area of square end end
Interface Segregation Principle (ISP)
This principle advises breaking interfaces into smaller ones to avoid forcing classes to implement methods they don't need.
Example: Interfaces for updating and displaying data.
module UpdateableFeature def update_feature # Logic for updating feature end end module DisplayableFeature def display_feature # Logic for displaying feature end end
Dependency Inversion Principle (DIP)
This principle suggests using dependency injection to manage dependencies.
Example: Using dependency injection to manage dependencies.
class OrderProcessor def initialize(db_connection, email_service) @db_connection = db_connection @email_service = email_service end end
Remember that applying SOLID principles in Ruby should be done flexibly based on the specific purpose of your project and your understanding of SOLID and Ruby.