koa2 原生路由实现

简单例子

const Koa = require('koa')
const app = new Koa()

app.use( async ( ctx ) => {
  let url = ctx.request.url
  ctx.body = url
})
app.listen(3000)
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访问 http://localhost:3000/hello/world 页面会输出 /hello/world,也就是说上下文的请求request对象中url之就是当前访问的路径名称,可以根据ctx.request.url 通过一定的判断或者正则匹配就可以定制出所需要的路由。

定制化的路由

demo源码

https://github.com/ChenShenhai/koa2-note/tree/master/demo/route-simpleopen in new window

源码文件目录

.
├── index.js
├── package.json
└── view
    ├── 404.html
    ├── index.html
    └── todo.html
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demo源码

const Koa = require('koa')
const fs = require('fs')
const app = new Koa()

// 用Promise封装异步读取文件方法
// @param  {string} page html文件名称
// @return {promise}      

function render( page ) {
  return new Promise(( resolve, reject ) => {
    let viewUrl = `./view/${page}`
    fs.readFile(viewUrl, "binary", ( err, data ) => {
      if ( err ) {
        reject( err )
      } else {
        resolve( data )
      }
    })
  })
}

/**
 * 根据URL获取HTML内容
 * @param  {string} url koa2上下文的url,ctx.url
 * @return {string}     获取HTML文件内容
 */
async function route( url ) {
  let view = '404.html'
  switch ( url ) {
    case '/':
      view = 'index.html'
      break
    case '/index':
      view = 'index.html'
      break
    case '/todo':
      view = 'todo.html'
      break
    case '/404':
      view = '404.html'
      break
    default:
      break
  }
  let html = await render( view )
  return html
}

app.use( async ( ctx ) => {
  let url = ctx.request.url
  let html = await route( url )
  ctx.body = html
})

app.listen(3000)
console.log('[demo] route-simple is starting at port 3000')

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运行demo

执行运行脚本

node -harmony index.js
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运行效果如下

访问http://localhost:3000/indexopen in new window

上次更新: 12/2/2022, 8:40:18 AM
Contributors: 九旬