Code explainers tagged #state-management

import { useReducer, useCallback } from 'react';
 
function historyReducer(state, action) {
  const { past, present, future } = state;

import { useState } from 'react';
 
function StarRating({ value = 0, max = 5, onChange, size = 24 }) {
  const [hovered, setHovered] = useState(null);

import { Injectable, signal, computed, effect, inject } from '@angular/core';
import { DOCUMENT } from '@angular/common';
 
export type Theme = 'light' | 'dark';

use axum::{
    extract::{FromRequestParts, Host},
    http::{request::Parts, StatusCode},
};

import { useState } from 'react';
 
export function ReorderableList({ initialItems }) {
  const [items, setItems] = useState(initialItems);

import { useCallback, useEffect, useRef, useState } from "react";
 
interface UseResendCooldownOptions {
  cooldownSeconds?: number;

import { Injectable, computed, effect, signal } from '@angular/core';
 
export interface CartLine {
  id: string;

import { useState, useRef, useCallback } from "react";
 
export function MultiSelect({ options, value, onChange, placeholder = "Select…" }) {
  const [open, setOpen] = useState(false);

class StarRating {
  constructor(container, { max = 5, value = 0, onChange } = {}) {
    this.container = container;
    this.max = max;

import { useState, useEffect, useCallback } from 'react';
 
export function useCountdown(initialSeconds) {
  const [secondsLeft, setSecondsLeft] = useState(initialSeconds);

import { Injectable, signal, computed } from '@angular/core';
 
export type ToastKind = 'success' | 'error' | 'info' | 'warning';
 

import { useState, useRef } from "react";
 
export function TagInput({ initialTags = [], onChange }) {
  const [tags, setTags] = useState(initialTags);

import { createContext, useContext, useState, useId } from "react";
 
const AccordionContext = createContext(null);
const ItemContext = createContext(null);

type CountdownState = {
  deadline: number;
  onTick: (remaining: number) => void;
  onComplete: () => void;

class HistoryStack {
  constructor(initial = '', limit = 100) {
    this.past = [];
    this.present = initial;

import { useState, useCallback, useRef } from 'react';
 
function LikeButton({ postId, initialLiked, initialCount }) {
  const [liked, setLiked] = useState(initialLiked);

import { useState } from 'react';
 
const steps = ['account', 'profile', 'review'];
 

import { useState } from "react";
 
const EMAIL_RE = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;