Inversion of Control (IoC) Architecture

Inversion of Control (IoC) is a design principle used in software architecture that transfers the control of object creation and management to a container or framework. This pattern is a fundamental concept in frameworks like Spring and .NET, enhancing modularity and reducing tight coupling between components.

What is IoC?

IoC allows for the decoupling of components in applications, promoting more maintainable and testable code.

Types of IoC

• Dependency Injection
• Service Locator

Implementing Dependency Injection

1. Identify the dependencies of your class.
2. Define interfaces for these dependencies.
3. Use a container to manage the instantiation of these dependencies.
4. Inject dependencies into the class via constructor, property, or method injection.

class NotificationService {
    send(message) {
        console.log("Sending message:", message);
    }
}

class User {
    constructor(notificationService) {
        this.notificationService = notificationService;
    }

    notify(message) {
        this.notificationService.send(message);
    }
}

// Dependency injection
const notificationService = new NotificationService();
const user = new User(notificationService);
user.notify("Hello, IoC!");
                    

Recommended Practices

• Use interfaces to define contracts for dependencies.
• Favor constructor injection for mandatory dependencies.
• Limit the number of dependencies in a single class.