react-state-management

React State Management

Comprehensive guide to modern React state management patterns, from local component state to global stores and server state synchronization.

When to Use This Skill

• Setting up global state management in a React app
• Choosing between Redux Toolkit, Zustand, or Jotai
• Managing server state with React Query or SWR
• Implementing optimistic updates
• Debugging state-related issues
• Migrating from legacy Redux to modern patterns

Core Concepts

1. State Categories

Type	Description	Solutions
Local State	Component-specific, UI state	useState, useReducer
Global State	Shared across components	Redux Toolkit, Zustand, Jotai
Server State	Remote data, caching	React Query, SWR, RTK Query
URL State	Route parameters, search	React Router, nuqs
Form State	Input values, validation	React Hook Form, Formik

2. Selection Criteria

Small app, simple state → Zustand or Jotai
Large app, complex state → Redux Toolkit
Heavy server interaction → React Query + light client state
Atomic/granular updates → Jotai

Quick Start

Zustand (Simplest)

// store/useStore.ts
import { create } from 'zustand'
import { devtools, persist } from 'zustand/middleware'

interface AppState {
  user: User | null
  theme: 'light' | 'dark'
  setUser: (user: User | null) => void
  toggleTheme: () => void
}

export const useStore = create<AppState>()(
  devtools(
    persist(
      (set) => ({
        user: null,
        theme: 'light',
        setUser: (user) => set({ user }),
        toggleTheme: () => set((state) => ({
          theme: state.theme === 'light' ? 'dark' : 'light'
        })),
      }),
      { name: 'app-storage' }
    )
  )
)

// Usage in component
function Header() {
  const { user, theme, toggleTheme } = useStore()
  return (
    <header className={theme}>
      {user?.name}
      <button onClick={toggleTheme}>Toggle Theme</button>
    </header>
  )
}