koa路由使用

超、凢脫俗 2022-04-22 16:20 161阅读 0赞

其实，router这个是一个很重要的内容，用户进行url访问就可以更好的使用

## 不用router中间件 ##

app.use(async (ctx,next)=>{
      if (ctx.path === '/') {
        ctx.body = 'we are at home!';
      } else {
        await next;
      }
    })
    
    app.use(async (ctx,next)=>{
      if (ctx.path === '/404') {
        ctx.body = 'page not found';
      } else {
        await next;
      }
    })

## 中间件写法 ##

const Koa = require('koa')
    const fs = require('fs')
    const app = new Koa()
    
    const Router = require('koa-router')
    
    let home = new Router()
    
    // 子路由1
    home.get('/', async ( ctx )=>{
      let html = `
        <ul>
          <li><a href="/page/helloworld">/page/helloworld</a></li>
          <li><a href="/page/404">/page/404</a></li>
        </ul>
      `
      ctx.body = html
    })
    
    // 子路由2
    let page = new Router()
    page.get('/404', async ( ctx )=>{
      ctx.body = '404 page!'
    }).get('/helloworld', async ( ctx )=>{
      ctx.body = 'helloworld page!'
    })
    
    // 装载所有子路由
    let router = new Router()
    router.use('/', home.routes(), home.allowedMethods())
    router.use('/page', page.routes(), page.allowedMethods())
    
    // 加载路由中间件
    app.use(router.routes()).use(router.allowedMethods())
    
    app.listen(3000, () => {
      console.log('[demo] route-use-middleware is starting at port 3000')
    })

## koa-router相关API ##

router
      .get('/', async (ctx, next) => {
        ctx.body = 'Hello World!';
      })
      .post('/users', async (ctx, next) => {...})
      .put('/users/:id', async (ctx, next) => {...})
      .del('/users/:id', async (ctx, next) => {...})
      .all('/users/:id', async (ctx, next) => {...})

router.all()用于表示上述所有的动词方法

router.get('/', async (ctx,next) => {
      ctx.body = 'Hello World!';
    });

上面代码中，router.get方法的第一个参数是根路径，第二个参数是对应的函数方法。

## 路由参数 ##

我们可以通过ctx.params得到URL参数

router.get('/:category/:title', function (ctx, next) {
      console.log(ctx.params);
      // => { category: 'programming', title: 'how-to-node' }
    });

这里有个中路由中间件汇集[https://cnodejs.org/topic/57838dfaee5f048d54f90877][https_cnodejs.org_topic_57838dfaee5f048d54f90877]

参考：

[https://chenshenhai.github.io/koa2-note/note/route/koa-router.html][https_chenshenhai.github.io_koa2-note_note_route_koa-router.html]

[https://gaianote.github.io/2017/04/24/koa2%E5%AD%A6%E4%B9%A0%E7%B3%BB%E5%88%97%E6%95%99%E7%A8%8B3\_%E8%B7%AF%E7%94%B1%E4%B8%8Ekoa-router/][https_gaianote.github.io_2017_04_24_koa2_E5_AD_A6_E4_B9_A0_E7_B3_BB_E5_88_97_E6_95_99_E7_A8_8B3_E8_B7_AF_E7_94_B1_E4_B8_8Ekoa-router]

[https://github.com/minghe/koa-book/blob/master/start/router.md][https_github.com_minghe_koa-book_blob_master_start_router.md]

转载：https://www.jianshu.com/p/0d59a4270997

[https_cnodejs.org_topic_57838dfaee5f048d54f90877]: https://cnodejs.org/topic/57838dfaee5f048d54f90877
[https_chenshenhai.github.io_koa2-note_note_route_koa-router.html]: https://chenshenhai.github.io/koa2-note/note/route/koa-router.html
[https_gaianote.github.io_2017_04_24_koa2_E5_AD_A6_E4_B9_A0_E7_B3_BB_E5_88_97_E6_95_99_E7_A8_8B3_E8_B7_AF_E7_94_B1_E4_B8_8Ekoa-router]: https://gaianote.github.io/2017/04/24/koa2%E5%AD%A6%E4%B9%A0%E7%B3%BB%E5%88%97%E6%95%99%E7%A8%8B3_%E8%B7%AF%E7%94%B1%E4%B8%8Ekoa-router/
[https_github.com_minghe_koa-book_blob_master_start_router.md]: https://github.com/minghe/koa-book/blob/master/start/router.md