@ereo/state

Signals and reactivity system for the EreoJS framework. Provides fine-grained reactive state management with a simple API.

Installation

bun add @ereo/state

Quick Start

import { signal, computed, createStore } from '@ereo/state';

// Create a signal
const count = signal(0);

// Read value
console.log(count.get()); // 0

// Update value
count.set(1);
count.update(n => n + 1);

// Subscribe to changes
const unsubscribe = count.subscribe(value => {
  console.log('Count changed:', value);
});

// Create computed signals
const doubled = computed(() => count.get() * 2, [count]);

Using Stores

import { createStore } from '@ereo/state';

interface AppState {
  user: string | null;
  theme: 'light' | 'dark';
  count: number;
}

const store = createStore<AppState>({
  user: null,
  theme: 'light',
  count: 0,
});

// Get signal for a specific key
const userSignal = store.get('user');

// Set value
store.set('theme', 'dark');

// Get snapshot of all values
const snapshot = store.getSnapshot();

Key Features

• Signals: Fine-grained reactive primitives with automatic change detection
• Computed Values: Derived state that updates automatically when dependencies change
• Stores: Centralized state management with key-value access
• Subscriptions: React to state changes with subscribe/unsubscribe pattern
• Batch Updates: Group multiple updates to minimize re-renders
• Map Transform: Transform signals with the map() method
• TypeScript Support: Full type inference and safety

API Reference

• signal<T>(value) - Create a reactive signal
• atom<T>(value) - Alias for signal
• computed<T>(fn, deps) - Create a computed signal
• batch(fn) - Batch multiple updates
• createStore<T>(state) - Create a reactive store

Documentation

For full documentation, visit the EreoJS Documentation.

Part of EreoJS

This package is part of the EreoJS monorepo - a modern full-stack JavaScript framework.

License

MIT