浅谈KOA2 Restful方式路由初探

前言

最近考虑将服务器资源整合一下，作为多端调用的API

看到Restful标准和ORM眼前一亮,但是找了不少版本路由写的都比较麻烦，于是自己折腾了半天

API库结构

考虑到全部对象置于顶层将会造成对象名越来长，同时不便于维护，故采取部分的分层结构

如workflow模块内的prototypes,instances等等，分层的深度定义为层级

可访问的对象集合(collection)的属性满足Restful设计

 -- workflow(category)  -- prototypes(collection)    -- [method] ...    -- [method] ...   -- instances(collection) -- users(collection)   --[method] List     #get :object/   --[method] Instance   #get :object/:id -- ... -- ...

RESTFUL API 接口

将Restful API接口进行标准化命名

.get('/', ctx=>{ctx.error('路径匹配失败')})        .get('/:object', RestfulAPIMethods.List).get('/:object/:id', RestfulAPIMethods.Get).post('/:object', RestfulAPIMethods.Post).put('/:object/:id', RestfulAPIMethods.Replace).patch('/:object/:id', RestfulAPIMethods.Patch).delete('/:object/:id', RestfulAPIMethods.Delete).get('/:object/:id/:related', RestfulAPIMethods.Related).post('/:object/:id/:related', RestfulAPIMethods.AddRelated).delete('/:object/:id/:related/:relatedId', RestfulAPIMethods.DelRelated)

API对象

这个文件是来自微信小程序demo，觉得很方便就拿来用了，放于需要引用的根目录，引用后直接获得文件目录结构API对象

const _ = require('lodash')const fs = require('fs')const path = require('path')/** * 映射 d 文件夹下的文件为模块 */const mapDir = d => {  const tree = {}  // 获得当前文件夹下的所有的文件夹和文件  const [dirs, files] = _(fs.readdirSync(d)).partition(p => fs.statSync(path.join(d, p)).isDirectory())  // 映射文件夹  dirs.forEach(dir => {    tree[dir] = mapDir(path.join(d, dir))  })  // 映射文件  files.forEach(file => {    if (path.extname(file) === '.js') {      tree[path.basename(file, '.js')] = require(path.join(d, file))      tree[path.basename(file, '.js')].isCollection = true    }  })  return tree}// 默认导出当前文件夹下的映射module.exports = mapDir(path.join(__dirname))

koa-router分层路由的实现

创建多层路由及其传递关系

执行顺序为

 1 -- 路径匹配
    -- 匹配到‘/'结束
    -- 匹配到对应的RestfulAPI执行并结束
    -- 继续
 2 -- 传递中间件 Nest
 3 -- 下一级路由
 4 -- 循环 to 1

const DefinedRouterDepth = 2let routers = []for (let i = 0; i < DefinedRouterDepth; i++) {  let route = require('koa-router')()  if (i == DefinedRouterDepth - 1) {    // 嵌套路由中间件    route.use(async (ctx, next) => {      // 根据版本号选择库      let apiVersion = ctx.headers['api-version']      ctx.debug(`------- (API版本 [${apiVersion}]) --=-------`)       if (!apiVersion) {        ctx.error('版本号未标记')        return      }      let APIRoot = null      try {        APIRoot = require(`../restful/${apiVersion}`)      } catch (e) {        ctx.error ('API不存在,请检查Header中的版本号')        return      }      ctx.debug(APIRoot)      ctx.apiRoot = APIRoot      ctx.debug('---------------------------------------------')      // for(let i=0;i<)      await next()    })  }  route    .get('/', ctx=>{ctx.error('路径匹配失败')})    .get('/:object', RestfulAPIMethods.List)    .get('/:object/:id', RestfulAPIMethods.Get)    .post('/:object', RestfulAPIMethods.Post)    .put('/:object/:id', RestfulAPIMethods.Replace)    .patch('/:object/:id', RestfulAPIMethods.Patch)    .delete('/:object/:id', RestfulAPIMethods.Delete)    .get('/:object/:id/:related', RestfulAPIMethods.Related)    .post('/:object/:id/:related', RestfulAPIMethods.AddRelated)    .delete('/:object/:id/:related/:relatedId', RestfulAPIMethods.DelRelated)  if (i != 0) {    route.use('/:object', Nest, routers[i - 1].routes())  }  routers.push(route)}let = router = routers[routers.length - 1]