重拾koa2之路由

const Koa = require('koa2')
const app = new Koa()

app.use(async ctx =>{
    ctx.body = ctx.request.url
    console.log(ctx.request.url)
})

app.listen(3000)

(async ()=>{

    const Koa = require('koa2')
    const fs = require('fs')
    const app = new Koa()
    
    // 使用Pormise封装异步读取文件方法
    function render(page) {
        return new Promise((relove, reject) => {
            let view = `./public/${page}`
            // 二进制读取文件
            fs.readFile(view, "binary", (err, data) => {
                if (err) {
                    reject(err)
                } else {
                    resolve(data)
                }
            })
        })
    }
    
    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
        }
        let html = await render(view)
        return html
    }
    
    app.use(ctx=>{
        let url = ctx.request.url
        let html = await route(url)
        ctx.body = html
    })
    
    app.listen(3000)
    console.log("a simple router is runing ")

})()

const koa = require('koa2')
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 = `
        <button>test</button>
    `
    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('a koa-router-use-middleware is running')
})