DAY19:React與Flask進行更深入的整合

2024 iThome 鐵人賽

DAY 19

Python

Python自修系列第 19 篇

16th鐵人賽

frankfrank8785

2024-08-22 20:15:03

202 瀏覽

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app.py

from flask import Flask, jsonify, render_template

app = Flask(__name__)

# 定義首頁路由，渲染 React 的入口 HTML 文件
@app.route('/')
def index():
    return render_template('index.html')

# 定義一個 API 路由，返回 JSON 數據
@app.route('/api/chart-data')
def chart_data():
    data = {
        "labels": ["January", "February", "March", "April", "May", "June"],
        "datasets": [{
            "label": "My First dataset",
            "backgroundColor": "rgba(255, 99, 132, 0.2)",
            "borderColor": "rgba(255, 99, 132, 1)",
            "borderWidth": 1,
            "data": [65, 59, 80, 81, 56, 55]
        }]
    }
    return jsonify(data)

# 啟動 Flask 應用
if __name__ == '__main__':
    app.run(debug=True)

index.html

<!DOCTYPE html>
<html lang="zh-Hant">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>第十九天 - React 與 Flask 整合及數據可視化</title>
    <script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
</head>
<body>
    <div id="root"></div>
    <script src="https://unpkg.com/react@17/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>
    <script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>
    <script type="text/babel">

        function App() {
            const [chartData, setChartData] = React.useState(null);

            React.useEffect(() => {
                fetch('/api/chart-data')
                    .then(response => response.json())
                    .then(data => setChartData(data));
            }, []);

            React.useEffect(() => {
                if (chartData) {
                    const ctx = document.getElementById('myChart').getContext('2d');
                    new Chart(ctx, {
                        type: 'bar',
                        data: chartData,
                        options: {
                            scales: {
                                y: {
                                    beginAtZero: true
                                }
                            }
                        }
                    });
                }
            }, [chartData]);

            return (
                <div>
                    <h1>第十九天的 React 與 Flask 整合及數據可視化示範</h1>
                    <canvas id="myChart"></canvas>
                </div>
            );
        }

        ReactDOM.render(<App />, document.getElementById('root'));
    </script>
</body>
</html>