API 中间件

Next.js提供了内置的路由中间件用于解析入参等。

• req.cookies：获取客户端的 cookie
• req.query：获取客户端的 query
• req.body：获取客户端的 body

export default (req, res) => {
  res.statusCode = 200
  res.setHeader('Content-Type', 'application/json')
  res.end(JSON.stringify({query: req.query}))
}

配置跨域

你还可以使用 Connect 兼容的中间件，比如使用 cors：

import Cors from 'cors'

// Initializing the cors middleware
const cors = Cors({
  methods: ['GET', 'HEAD']
})

// Helper method to wait for a middleware to execute before continuing
// And to throw an error when an error happens in a middleware
function runMiddleware(req, res, fn) {
  return new Promise((resolve, reject) => {
    fn(req, res, (result) => {
      if (result instanceof Error) {
        return reject(result)
      }

      return resolve(result)
    })
  })
}

async function handler(req, res) {
  // Run the middleware
  await runMiddleware(req, res, cors)

  // Rest of the API logic
  res.json({message: 'Hello Everyone!'})
}

export default handler