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 = 2
let 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]
Nest中间件
将ctx.apiObject设置为当前层的API对象
const Nest= async (ctx, next) => {
let object = ctx.params.object
let apiObject = ctx.apiObject || ctx.apiRoot
if(!apiObject){
ctx.error('API装载异常')
return
}
if (apiObject[object]) {
ctx.debug(`ctx.apiObject=>ctx.apiObject[object]`)
ctx.debug(apiObject[object])
ctx.debug(`------------------------------------`)
ctx.apiObject = apiObject[object]
} else {
ctx.error(`API接口${object}不存在`)
return
}
await next()
}
RestfulAPIMethods
let RestfulAPIMethods = {}
let Methods = ['List', 'Get', 'Post', 'Replace', 'Patch', 'Delete', 'Related', 'AddRelated', 'DelRelated']
for (let i = 0; i < Methods.length; i++) {
let v = Methods[i]
RestfulAPIMethods[v] = async function (ctx, next) {
let apiObject = ctx.apiObject || ctx.apiRoot
if (!apiObject) {
ctx.error ('API装载异常')
return
}
let object = ctx.params.object
if (apiObject[object] && apiObject[object].isCollection) {
ctx.debug(` --- Restful API [${v}] 调用--- `)
if (typeof apiObject[object][v] == 'function') {
ctx.state.data = await apiObject[object][v](ctx)
ctx.debug('路由结束')
return
//ctx.debug(ctx.state.data)
} else {
ctx.error(`对象${object}不存在操作${v}`)
return
}
}
ctx.debug(` --- 当前对象${object}并不是可访问对象 --- `)
await next()
}
}
需要注意的点
1、koa-router的调用顺序
2、涉及到async注意next()需要加await
