如何在Express中定位当前页面导航？

const express = require('express');
const app = express();

// 导航中间件
app.use((req, res, next) => {
  // 获取当前URL路径
  const currentPath = req.url;

  // 设置导航信息
  res.locals.nav = {
    home: currentPath === '/',
    about: currentPath === '/about',
    contact: currentPath === '/contact'
  };

  next();
});

// 路由处理程序
app.get('/', (req, res) => {
  res.render('home', { nav: res.locals.nav });
});

app.get('/about', (req, res) => {
  res.render('about', { nav: res.locals.nav });
});

app.get('/contact', (req, res) => {
  res.render('contact', { nav: res.locals.nav });
});

// 启动服务器
app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

<ul>
  <li <% if (nav.home) { %>class="active"<% } %>><a href="/">Home</a></li>
  <li <% if (nav.about) { %>class="active"<% } %>><a href="/about">About</a></li>
  <li <% if (nav.contact) { %>class="active"<% } %>><a href="/contact">Contact</a></li>
</ul>