Kamui

A powerful, type-safe event bus system for TypeScript applications with advanced event handling capabilities.

Features

• 🔒 Type-safe Event Handling: Fully typed event system that catches type errors at compile time
• 🚀 High Performance: Efficient event dispatching with Set-based listener management
• 🎯 Event Metadata: Automatic tracking of event IDs, timestamps, and names
• 🔄 Flexible Architecture: Support for both EventBus and EventEmitter patterns
• 🛠 Extensible Design: Easy to extend and adapt to different use cases

Installation

npm install kamui
# or
yarn add kamui
# or
pnpm add kamui

Usage

Basic Event Bus Usage

import { createEventBus, ExtendedEventListener } from 'kamui';

// Define your event types
type UserEvents = {
  'user:created': ExtendedEventListener<{ id: string; name: string }>[];
  'user:updated': ExtendedEventListener<{ id: string; changes: Record<string, any> }>[];
};

// Create event bus instance
const eventBus = createEventBus<UserEvents>({
  'user:created': [],
  'user:updated': []
});

// Emit an event
eventBus.emit('user:created', { 
  id: '123', 
  name: 'John Doe' 
});

Using Event Creator

import { createEvent } from 'kamui';

type UserCreatedPayload = { id: string; name: string };

const userCreatedListeners = createEvent<UserCreatedPayload>(
  (payload, metadata) => {
    console.log(`User created: ${payload.name} at ${metadata?.timestamp}`);
  }
);

Event Emitter Adapter

import { createEventEmitter } from 'kamui';

const events = [
  {
    name: 'userCreated',
    listeners: [(metadata, payload) => console.log(payload)]
  }
];

const emitter = createEventEmitter(events);
emitter.emit('userCreated', { id: '123', name: 'John Doe' });

API Reference

EventBus

• createEventBus<T>(events): Creates a new event bus instance
• emit(eventName, payload): Emits an event with the given name and payload
• getListenerCount(eventName): Returns the number of listeners for an event

EventCreator

• createEvent<T>(...listeners): Creates a new event with the given listeners
• addListener(listener): Adds a new listener to an event
• getListeners(): Returns all listeners for an event

Event Types

• EventMetadata: Contains event metadata (id, timestamp, name)
• EventListener<T>: Basic event listener type
• ExtendedEventListener<T>: Event listener with metadata support

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT