ErrorBoundary

src/App.jsx

@@ -1,59 +1,111 @@
-import { memo, useState, useMemo } from 'react'
+import React from 'react'
 
-function memoize(fn) {
+class ErrorBoundary extends React.Component {
-    const cache = new Map();
+    constructor(props) {
-    return function(...args) {
+        super(props);
-        const key = JSON.stringify(args);
+        this.state = {hasError: false};
-        if (cache.has(key)) {
-            return cache.get(key);
-        }
-        const result = fn.apply(this, args);
-        cache.set(key,result);
-        return result;
-    }
     }
     
-function fibonachi(n, memo={}) {
+    static getDerivedStateFromError(error) {
-    if (n in memo) {console.log(n);return memo[n];}
+        return { hasError: true }
-    if (n <= 1) return 1;
-    memo[n] = fibonachi(n-1, memo) + fibonachi(n - 2, memo);
-    return memo[n];
     }
     
-const MyComponent = ({ value }) => {
+    componentDidCatch(error,info) {
-    console.log('Rendring');
+        console.log(error,info);
-    return <div>{value}</div>
     }
     
-const MemoizedComponent = memo(MyComponent);
+    handlerReset = () => {
-
+        this.setState({hasError: false});
-const Child = memo(({ children }) => {
+    }
-    console.log('Child component rendred');
-    return <div>{children}</div>;
-});
-
-const Parent = () => {
-    const [count,setCount] = useState(0);
-    const [text, setText] = useState('');
-    
-    const stableChild = useMemo(() => <span>Memo text</span>,[]);
     
+    render() {
+        if (this.state.hasError) {
             return (
-        <>
+                <div>
-            <Child>
+                    <h1>Что то поломалось</h1>
-                {stableChild}
+                    <button onClick={this.handlerReset}>Повторить</button>
-            </Child>
+                </div>)
-            <input type="text" onChange={(e) => setText(e.target.value)} value={text} />
+        }
-            <button onClick={() => setCount(count + 1)}>Increment {count}</button>
+        return this.props.children;
-        </>
+    }
+}
+
+class AdvancedErrorBoundary extends React.Component {
+    constructor(props) {
+        super(props);
+        this.state = {
+            hasError: false,
+            error: null,
+            errorInfo: null
+        }
+    }
+    
+    static getDerivedStateFromError(error) {
+        return { hasErorr: true }
+    }
+    
+    componentDidCatch(error, info) {
+        this.setState({ 
+            error: error,
+            errorInfo: info
+        })
+    }
+    
+    handleReset = () => {
+        this.setState({
+            hasError:false,
+            error: null,
+            errorInfo:null
+        });
+    }
+    
+    render() {
+        if(this.state.hasError) {
+            console.log('Error');
+            return (
+                <div>
+                    <h2>Произошла ошибка</h2>
+                    <p>Извеняемся, работаем, исправляем. Разработчика привязали к батарее</p>
+                    <button onClick={this.handleReset}>Попробовать снова</button>
+                </div>
+            )
+        }
+        //Если ошибок нет, то рендрим дочерние объекты
+        return this.props.children
+    }
+}
+
+function ProblemComponent() {
+    const [counter,setCounter] = React.useState(0)
+    
+    const handlerClick = () => setCounter(counter + 1)
+    
+    React.useEffect(() => {
+        if (counter > 5) {
+            throw new Error("Ошибка в компоненте");
+        }
+    },[counter]);
+    return (
+        <div>
+            <h2>Счетчик: {counter}</h2>
+            <button onClick={handlerClick}>Прибавить</button>
+        </div>
     )
 }
 
 function App() {
 	return (
 		<>
-			<h1>Hello, React!</h1>
+			<h1>Обработка ошибок в компонентах</h1>
-            <Parent />
+            <ErrorBoundary>
+                <ProblemComponent />
+            </ErrorBoundary>
+            <ErrorBoundary>
+                <ProblemComponent />
+            </ErrorBoundary>
+            <ErrorBoundary>
+                <ProblemComponent />
+            </ErrorBoundary>
 		</>
 	)
 }

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>
 )