Main differences between Design Patterns and SOLID principles
Design patterns:
Specific Solutions: Design patterns are specific, low-level solutions to recurring problems in software design.
Implementation Details: Provide concrete implementation guidelines for solving common object-oriented programming challenges.
Examples: Some well-known design patterns include the Singleton, Factory Method, and Adapter patterns.
Safety: The design patterns are tested and widely accepted by the community, making them safe to follow.
SOLID principles:
General Guidelines: The SOLID principles are high-level guidelines that inform good software design.
Scalable architecture: They focus on scalability, maintainability, and readability.
Not bound to language: SOLID principles are not bound to any specific programming language.
Examples:
Single Responsibility Principle (SRP): A class should have only one reason to change.
Open/close principle (OCP): Software entities should be open for extension but closed for modification.
Liskov Substitution Principle (LSP): Subtypes must be replaceable with their base types.
Interface Segregation Principle (ISP): Clients should not be forced to depend on interfaces that they do not use.
Dependency Inversion Principle (DIP): High-level modules should not depend on low-level modules; both should depend on abstractions.
In summary, design patterns offer specific solutions, while SOLID principles provide general guidelines for better software design
Advantages of Using Design Patterns
Reusability: Design patterns are reusable solutions that can be applied to multiple projects. By using established patterns, developers save time and effort, as they don't need to reinvent the wheel for common problems.
Definition of architecture: Design patterns help defirefine the architecture of the software system. They provide a structured approach to solving specific design challenges, ensuring consistency and maintainability.
Flexibility: Templates allow flexibility in adapting to changing needs. When new features or changes are needed, developers can modify or extend existing templates without breaking the entire system.
Disadvantages of using Design Patterns
Learning curve: Understanding and applying design patterns requires knowledge and experience. Novice developers may find it difficult to understand the concepts and choose the right model for a given problem.
Excessive use: Having readily available design patterns can lead to the misconception that all problems can be solved using existing patterns. Excessive use of templates can limit creativity and hinder the search for better, more innovative solutions.
Complexity- Some design patterns introduce additional complexity into the code base. Developers must find a balance between using patterns effectively and making code understandable.
In summary, design patterns offer significant advantages in terms of reusability, architecture and flexibility, but their use should be judicious to avoid unnecessary complexity and promote creativity.
Example of Design Pattern in Laravel: Singleton
The Singleton design pattern ensures that a class has only one instance and provides a single point of entry. In Laravel, this model is often used to manage resources such as database connections or configuration settings.
Here is a basic example of Singleton pattern implementation in PHP:
<?php class Singleton { private static $instance = null;
private function __construct() { // Private constructor to prevent direct instantiation }
public static function getInstance(): self { if (null === self::$instance) { self::$instance = new self(); } return self::$instance; }
// Other methods and properties can be added here }
// Usage: $singletonInstance = Singleton::getInstance(); // Now you have a single instance of the Singleton class
// Example usage in Laravel: $database = DB::connection('mysql'); // Retrieve a database connection instance (singleton)
In the sample code:
The Singleton class has a private constructor to prevent direct instantiation;
The getInstance() method guarantees that only one instance of the class exists;
You can add other methods and properties to the Singleton class as needed;
The Laravel service container also uses the Singleton pattern to manage class dependencies and perform dependency injection. If you work within Laravel, consider using its service container and registering your class with a service provider for more advanced use cases.
