Сделали таймер

src/App.jsx

@@ -1,78 +1,108 @@
-import { useState, createContext, useContext } from 'react'
-import styles from './App.module.scss'
+import React from 'react'
 
-const UserContext = createContext('')
-
-function UserProvider({ children }) {
-    const [name,setName] = useState('');
-    
-    const toggleName = (newName) => {
-        setName(newName);
+class MyComponent extends React.Component {
+    constructor(props) {
+        super(props);
+        this.state = { data: null };
+        this.handleClick = this.handleClick.bind(this);
     }
     
-    return (
-        <UserContext.Provider value={{name, toggleName}}>
-            {children}
-        </UserContext.Provider>
-    )
-}
-
-function Form() {
-    const {name, toggleName} = useContext(UserContext)
-    const [newName,setNewName] = useState('');
-    const handleSubmit = (event) => {
-        event.preventDefault();
-        toggleName(event.target[0].value)
+    render() {
+        return (
+            <div>
+            {this.state.data ? (
+                    <div>Данные: {this.state.data}</div>
+                ) : (
+                    <div>Загрузка...</div>
+                )}
+                <button onClick={this.handleClick}>Обновить</button>
+            </div>
+        )
     }
-    const handlerChange = (event) => {
-        setNewName(event.target.value);
+    
+    componentDidMount() {
+        fetch('https://api.example.com/data')
+        .then(responce => responce.json())
+        .then(json => this.setState({data: json}));
+        
+        this.timerId = setInterval(()=> console.log('Tick'), 1000);
+    }
+    
+    componentWillUnmout() {
+        clearInterval(this.timerId);
+    }
+    
+    handleClick() {
+        this.setState({data: 'Данные'})
     }
-    return (
-        <form onSubmit={handleSubmit}>
-        <input type='text' value={newName} onChange={handlerChange} />
-        <button type='submit'>Войти</button>
-        </form>
-    )
 }
 
-function ExitButton() {
-    const {name, toggleName} = useContext(UserContext)
+class MyComponent2 extends React.Component {
+    controller = new AbortController()
 
-    return (
-        <button onClick={() => toggleName('')}>Выход</button>
-    )
+    componentDidMount() {
+        fetch('https://api.example.com/data',{ singnal: this.controller.signal })
+        .then(responce => responce.json())
+        .then(json => this.setState({data: json}))
+        .catch(error => {
+            if(error.name == 'AbortError') {
+                console.log('Aborted');
+            } else {
+                console.log('Other error',error);
+            }
+        });
+    }
+
+    componentWillUnmount() {
+        this.controller.abort()
+    }
+}
+class MyComponent3 extends React.Component {
+    componentDidMount() {
+        this.loadData();
+    }
+    
+    async loadData() {
+        try {
+            const response = await fetch('https://api.example.com/data');
+            const data = await response.json();
+            this.setSate({ data });
+        } catch {
+            console.log('error');
+        }
+    }
 }
 
-function Toolbar() {
-    const {name, toggleName} = useContext(UserContext)
-    return(
-        <div className={styles.container}>
-            <h3>Панель пользователя</h3>
-            {name && `Привет ${name}`}
-            {name ? <ExitButton /> : <Form /> }
+class Timer extends React.Component {
+    constructor(props) {
+        super(props);
+        this.state = { seconds: 0 }
+    }
     
-        </div>
-    )
-}
+    componentDidMount() {
+        console.log('Timer mounted');
+        this.interval = setInterval(()=>{
+            this.setState(prevState => ({seconds: prevState.seconds + 1}))
+        },1000);
+    }
     
-function Page() {
-    return (
-        <div>
-            <h1 style={{textAlign: 'center'}}>Главная страница</h1>
-            <Toolbar />
-        </div>
-    )
+    componentWillUnmount() {
+        console.log('Timer unmount');
+        clearInterval(this.interval);
+    }
+    render() {
+        return <h2>Прошло секунд: {this.state.seconds}</h2>
+    }
 }
 
 function App() {
+    const [show,setShow] = React.useState(true);
     
 	return (
 		<>
-			{/* Добавьте тестовый контент для проверки */}
-			<h1>Hello, React!</h1>
-        <UserProvider>
-            <Page />
-        </UserProvider>
+			<h1>Таймер с классом</h1>
+            <button onClick={()=>setShow(prev => !prev)}>{show ? 'Скрыть' : 'Показать'} таймер</button>
+            {show && <Timer />}
 		</>
 	)
 }

src/App.module.scss

@@ -1,13 +0,0 @@
-.container {
-    height: 500px;
-    border: 1px solid black;
-    border-radius: 10px;
-    background-color: lightblue;
-}
-.item {
-    font-size: 16pt;
-    border: 1px dotted gray;
-    /*margin: 5px 10px;
-    padding: 10px;*/
-    border-radius: 5px;
-}

src/main.jsx

@@ -4,7 +4,5 @@ import { createRoot } from 'react-dom/client'
 import App from './App.jsx'
 
 createRoot(document.getElementById('root')).render(
-	<StrictMode>
 		<App />
-	</StrictMode>
 )