DIContainer

DIContainer is a simple and flexible Dependency Injection container for JavaScript. It allows you to register and resolve services with dependencies, supporting both singleton and transient lifetimes.

Table of Contents

• Installation
• Usage
  • Registering Services
  • Resolving Services
• Examples
  • Registering a Singleton Service
  • Registering a Transient Service
  • Registering a Service with Dependencies
• License

Installation

You can add DIContainer to your project by copying the DIContainer class into your project.

Usage

Registering Services

To register a service, use the Register method. You need to provide:

• Name: The name of the service.
• Dependencies: An array of service names that this service depends on.
• Implementation: The implementation of the service. It can be a constructor function, a factory function, or an existing object.
• IsSingleton (optional): A boolean indicating if the service should be a singleton. Default is true.

Resolving Services

To resolve a service, use the Get method with the service name. This will return an instance of the service, with all its dependencies resolved.

Examples

Registering a Singleton Service

const container = new DIContainer();

class MyService {
    constructor() {
        this.name = 'MyService';
    }
}

container.Register('MyService', [], MyService);

const myServiceInstance = container.Get('MyService');
console.log(myServiceInstance.name); // Output: MyService

Registering a Transient Service

const container = new DIContainer();

class MyTransientService {
    constructor() {
        this.timestamp = Date.now();
    }
}

container.Register('MyTransientService', [], MyTransientService, false);

const instance1 = container.Get('MyTransientService');
const instance2 = container.Get('MyTransientService');
console.log(instance1.timestamp !== instance2.timestamp); // Output: true

Registering a Service with Dependencies

const container = new DIContainer();

class Logger {
    log(message) {
        console.log(message);
    }
}

class UserService {
    constructor(logger) {
        this.logger = logger;
    }

    getUser() {
        this.logger.log('Getting user');
        return { name: 'John Doe' };
    }
}

container.Register('Logger', [], Logger);
container.Register('UserService', ['Logger'], UserService);

const userService = container.Get('UserService');
const user = userService.getUser(); // Logs: Getting user
console.log(user.name); // Output: John Doe