Конец урока

src/App.jsx

@@ -1,110 +1,68 @@
-import React from 'react'
+import React, { useState, useReducer, useRef, memo } from 'react'
 
-class MyComponent extends React.Component {
+function tasksReducer(state, action) {
-    constructor(props) {
+    switch(action.type) {
-        super(props);
+        case 'ADD_TASK':
-        this.state = { data: null };
+            return [...state, action.payload]
-        this.handleClick = this.handleClick.bind(this);
+        case 'TOGGLE_TASK':
+            return state.map(task => task.id === action.payload ? {...task, complite: !task.complite} : task)
+        case 'REMOVE_TASK':
+            return state.filter(task => task.id !== action.payload)
+        default:
+            return state
+    }
 }
 
-    render() {
+const TaskList = memo(function TaskList({tasks, onToggle, onRemove}) {
+    console.log("Rendred")
     return (
-            <div>
+        <ul>
-            {this.state.data ? (
+        {tasks.map(({id, text, complite}) => (
-                    <div>Данные: {this.state.data}</div>
+                <li key={id}
-                ) : (
+                    style={{textDecoration: complite ? 'line-through' : 'none' }}>
-                    <div>Загрузка...</div>
+                    <input type="checkbox" checked={complite} onChange={()=>onToggle(id)} />
-                )}
+                    {text}
-                <button onClick={this.handleClick}>Обновить</button>
+                    <button onClick={()=> onRemove(id)} style={{marginLeft: 10}}>
+                        Удалить
+                    </button>
+                </li>
+            ))}
+        </ul>
+    )
+})
+
+function App() {
+    const [tasks, dispatch] = useReducer(tasksReducer,[])
+    const [input,setInput] = useState('')
+    const [error,setError] = useState('')
+    const inputRef = useRef(null)
+    
+    const addTask = () => {
+        if (input.trim() === '') {
+            setError('Пустой текст задачи')
+            return
+        }
+        setError('')
+        dispatch({
+            type: 'ADD_TASK',
+            payload: {id: Date.now(), text: input.trim(), complite: false }
+        })
+        setInput('')
+        inputRef.current.focus()
+    }
+    
+	return (
+		<div style={{padding: 20}}>
+			<h1>Список дел</h1>
+			<input ref={inputRef} value={input} onChange={e => setInput(e.target.value)} />
+			<button onClick={addTask}>Добавить</button>
+            {error && <p style={{color: 'red'}}>{error}</p>}
+            
+            <TaskList tasks={tasks} 
+                onToggle={id => dispatch({type: 'TOGGLE_TASK', payload: id})}
+                onRemove={id => dispatch({type: 'REMOVE_TASK', payload: id})} />
 		</div>
 	)
 }
 
-    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'})
-    }
-}
-
-class MyComponent2 extends React.Component {
-    controller = new AbortController()
-
-    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');
-        }
-    }
-}
-
-class Timer extends React.Component {
-    constructor(props) {
-        super(props);
-        this.state = { seconds: 0 }
-    }
-    
-    componentDidMount() {
-        console.log('Timer mounted');
-        this.interval = setInterval(()=>{
-            this.setState(prevState => ({seconds: prevState.seconds + 1}))
-        },1000);
-    }
-    
-    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 (
-		<>
-			<h1>Таймер с классом</h1>
-            <button onClick={()=>setShow(prev => !prev)}>{show ? 'Скрыть' : 'Показать'} таймер</button>
-            {show && <Timer />}
-		</>
-	)
-}
-
 export default App

src/main.jsx

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