React Suspense 加载状态组合：嵌套加载管理

            import React, { Suspense, lazy } from 'react';

const MyComponent = lazy(() => import('./MyComponent'));

function App() {
  return (
    <Suspense fallback={<p>Loading...</p>}>
      <MyComponent />
    </Suspense>
  );
}

export default App;

            

              
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            // Resource.js
const createResource = (promise) => {
  let status = 'pending';
  let result;
  let suspender = promise.then(
    (r) => {
      status = 'success';
      result = r;
    },
    (e) => {
      status = 'error';
      result = e;
    }
  );

  return {
    read() {
      if (status === 'pending') {
        throw suspender;
      } else if (status === 'error') {
        throw result;
      }
      return result;
    },
  };
};

export default createResource;

// MyComponent.js
import React from 'react';
import createResource from './Resource';

const fetchData = () =>
  new Promise((resolve) =>
    setTimeout(() => resolve({ data: 'Fetched Data!' }), 2000)
  );

const resource = createResource(fetchData());

function MyComponent() {
  const data = resource.read();
  return <p>{data.data}</p>;
}

export default MyComponent;

// App.js
import React, { Suspense } from 'react';
import MyComponent from './MyComponent';

function App() {
  return (
    <Suspense fallback={<p>Loading data...</p>}>
      <MyComponent />
    </Suspense>
  );
}

export default App;

            

              
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            import React, { Suspense, lazy } from 'react';

const Header = lazy(() => import('./Header'));
const MainContent = lazy(() => import('./MainContent'));
const Sidebar = lazy(() => import('./Sidebar'));

function App() {
  return (
    <div>
      <Suspense fallback={<p>Loading header...</p>}>
        <Header />
      </Suspense>
      <div style={{ display: 'flex' }}>
        <Suspense fallback={<p>Loading main content...</p>}>
          <MainContent />
        </Suspense>
        <Suspense fallback={<p>Loading sidebar...</p>}>
          <Sidebar />
        </Suspense>
      </div>
    </div>
  );
}

export default App;

            

              
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            import React, { Suspense, lazy } from 'react';

const Header = lazy(() => import('./Header'));
const MainContent = lazy(() => import('./MainContent'));

function App() {
  return (
    <Suspense fallback={<p>Loading header and content...</p>}>
      <Header />
      <Suspense fallback={<p>Loading main content...</p>}>
        <MainContent />
      </Suspense>
    </Suspense>
  );
}

export default App;

            

              
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            import React from 'react';
import Skeleton from 'react-loading-skeleton'; // You'll need to install this library

function LoadingSkeleton() {
  return (
    <div>
      <Skeleton count={3} />
    </div>
  );
}

export default LoadingSkeleton;

// Usage in App.js
import React, { Suspense, lazy } from 'react';
import LoadingSkeleton from './LoadingSkeleton';

const MyComponent = lazy(() => import('./MyComponent'));

function App() {
  return (
    <Suspense fallback={<LoadingSkeleton />}>
      <MyComponent />
    </Suspense>
  );
}

export default App;

            

              
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            import React, { Component } from 'react';

class ErrorBoundary extends Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false };
  }

  static getDerivedStateFromError(error) {
    // Update state so the next render will show the fallback UI.
    return { hasError: true };
  }

  componentDidCatch(error, errorInfo) {
    // You can also log the error to an error reporting service
    console.error(error, errorInfo);
  }

  render() {
    if (this.state.hasError) {
      // You can render any custom fallback UI
      return <h1>Something went wrong.</h1>;
    }

    return this.props.children;
  }
}

export default ErrorBoundary;

// Usage in App.js
import React, { Suspense, lazy } from 'react';
import ErrorBoundary from './ErrorBoundary';

const MyComponent = lazy(() => import('./MyComponent'));

function App() {
  return (
    <ErrorBoundary>
      <Suspense fallback={<p>Loading...</p>}>
        <MyComponent />
      </Suspense>
    </ErrorBoundary>
  );
}

export default App;

            

              
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            import React, { Suspense, lazy, useState, useTransition } from 'react';

const MyComponent = lazy(() => import('./MyComponent'));

function App() {
  const [isPending, startTransition] = useTransition();
  const [showComponent, setShowComponent] = useState(false);

  const handleClick = () => {
    startTransition(() => {
      setShowComponent(true);
    });
  };

  return (
    <div>
      <button onClick={handleClick} disabled={isPending}>
        {isPending ? 'Loading...' : 'Load Component'}
      </button>
      {showComponent && (
        <Suspense fallback={<p>Loading component...</p>}>
          <MyComponent />
        </Suspense>
      )}
    </div>
  );
}

export default App;

            

              
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            import React, { Suspense, lazy } from 'react';

const ProductDetails = lazy(() => import('./ProductDetails'));
const ProductReviews = lazy(() => import('./ProductReviews'));
const RelatedProducts = lazy(() => import('./RelatedProducts'));

function ProductPage() {
  return (
    <div>
      <Suspense fallback={<p>Loading product details...</p>}>
        <ProductDetails />
      </Suspense>

      <div style={{ marginTop: '20px' }}>
        <Suspense fallback={<p>Loading product reviews...</p>}>
          <ProductReviews />
        </Suspense>
      </div>

      <div style={{ marginTop: '20px' }}>
        <Suspense fallback={<p>Loading related products...</p>}>
          <RelatedProducts />
        </Suspense>
      </div>
    </div>
  );
}

export default ProductPage;

            

              
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