NotifiJs

A strongly-typed, lightweight, and zero-dependency Observer Pattern implementation in TypeScript — ideal for decoupling logic and managing event subscriptions in a reactive way.

Features

• ✅ Fully typed with TypeScript generics
• ✅ Extremely lightweight (no dependencies)
• ✅ Observer pattern compliant
• ✅ Safe and isolated notifications
• ✅ Modern and minimal API

Installation

npm install notifijs

Or with Yarn:

yarn add notifijs

Usage

import { Subject } from 'notifijs';

const counter = new Subject<number>();

const logger = (value: number) => {
  console.log(`Value changed to ${value}`);
};

counter.subscribe(logger);

counter.notify(1); // Console: Value changed to 1
counter.notify(2); // Console: Value changed to 2

counter.unsubscribe(logger);

counter.notify(3); // No output

API Reference

new Subject<T>()

Creates a new Subject instance for a given data type T.

.subscribe(observer: (value: T) => void): void

Adds an observer to the subscription list.

.unsubscribe(observer: (value: T) => void): void

Removes an observer.

.notify(value: T): void

Notifies all observers with the provided value. Each observer is executed independently with error isolation.

.clear(): void

Removes all observers.

.count(): number

Returns the number of subscribed observers.

Use Cases

• Reactivity in UI frameworks
• Logging and analytics hooks
• Pub/Sub for services or internal modules
• Decoupling side-effects from main logic
• Custom state management

Development

git clone https://github.com/MendoncaGabriel/Notifi-Js.git
cd Notifi-Js
npm install
npm run build

Links

• 🔗 GitHub Repository
• 📦 NPM Package
• 🌐 Live Demo

👨‍💻 Author

Gabriel Mendonça Full-stack Developer | TypeScript Lover LinkedIn • GitHub

📝 License

This project is licensed under the MIT License.