淺談KOA2 Restful方式路由初探
阿新 • • 發佈：2019-04-11
outer 根據 集合 pes str readdir 選擇 淺談 types
前言
最近考慮將服務器資源整合一下，作為多端調用的API
看到Restful標準和ORM眼前一亮,但是找了不少版本路由寫的都比較麻煩，於是自己折騰了半天
API庫結構
考慮到全部對象置於頂層將會造成對象名越來長，同時不便於維護，故采取部分的分層結構
如workflow模塊內的prototypes,instances等等，分層的深度定義為層級
可訪問的對象集合(collection)的屬性滿足Restful設計
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-- workflow(category)
-- prototypes(collection) -- [method] ...
-- [method] ...
-- instances(collection)
-- users(collection)
--[method] List #get :object/
--[method] Instance #get :object/:id
-- ...
-- ...
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RESTFUL API 接口
將Restful API接口進行標準化命名
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.get(‘/‘, ctx=>{ctx.error(‘路徑匹配失敗‘)})
.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)
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API對象
這個文件是來自微信小程序demo，覺得很方便就拿來用了，放於需要引用的根目錄，引用後直接獲得文件目錄結構API對象
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const _ = require(‘lodash‘)
const fs = require(‘fs‘)
const path = require(‘path‘)
/**
* 映射 d 文件夾下的文件為模塊
*/
const mapDir = d => {
const tree = {}
// 獲得當前文件夾下的所有的文件夾和文件
const [dirs, files] = _(fs.readdirSync(d)).partition(p => fs.statSync(path.join(d, p)).isDirectory())
// 映射文件夾
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
}
// 默認導出當前文件夾下的映射
module.exports = mapDir(path.join(__dirname))
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koa-router分層路由的實現
創建多層路由及其傳遞關系
執行順序為
1 -- 路徑匹配
-- 匹配到‘/‘結束
-- 匹配到對應的RestfulAPI執行並結束
-- 繼續
2 -- 傳遞中間件 Nest
3 -- 下一級路由
4 -- 循環 to 1
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const DefinedRouterDepth = 2
let routers = []
for (let i = 0; i < DefinedRouterDepth; i++) {
let route = require(‘koa-router‘)()
if (i == DefinedRouterDepth - 1) {
// 嵌套路由中間件
route.use(async (ctx, next) => {
// 根據版本號選擇庫
let apiVersion = ctx.headers[‘api-version‘]
ctx.debug(`------- (API版本 [${apiVersion}]) --=-------`)
if (!apiVersion) {
ctx.error(‘版本號未標記‘)
return
}
let APIRoot = null
try {
APIRoot = require(`../restful/${apiVersion}`)
} catch (e) {
ctx.error (‘API不存在,請檢查Header中的版本號‘)
return
}
ctx.debug(APIRoot)
ctx.apiRoot = APIRoot
ctx.debug(‘---------------------------------------------‘)
// for(let i=0;i<)
await next()
})
}
route
.get(‘/‘, ctx=>{ctx.error(‘路徑匹配失敗‘)})
.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]
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Nest中間件
將ctx.apiObject設置為當前層的API對象
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const Nest= async (ctx, next) => {
let object = ctx.params.object
let apiObject = ctx.apiObject || ctx.apiRoot
if(!apiObject){
ctx.error(‘API裝載異常‘)
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${object}不存在`)
return
}
await next()
}
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RestfulAPIMethods
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let RestfulAPIMethods = {}
let Methods = [‘List‘, ‘Get‘, ‘Post‘, ‘Replace‘, ‘Patch‘, ‘Delete‘, ‘Related‘, ‘AddRelated‘, ‘DelRelated‘]
for (let i = 0; i < Methods.length; i++) {
let v = Methods[i]
RestfulAPIMethods[v] = async function (ctx, next) {
let apiObject = ctx.apiObject || ctx.apiRoot
if (!apiObject) {
ctx.error (‘API裝載異常‘)
return
}
let object = ctx.params.object
if (apiObject[object] && apiObject[object].isCollection) {
ctx.debug(` --- Restful API [${v}] 調用--- `)
if (typeof apiObject[object][v] == ‘function‘) {
ctx.state.data = await apiObject[object][v](ctx)
ctx.debug(‘路由結束‘)
return
//ctx.debug(ctx.state.data)
} else {
ctx.error(`對象${object}不存在操作${v}`)
return
}
}
ctx.debug(` --- 當前對象${object}並不是可訪問對象 --- `)
await next()
}
}
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需要註意的點
1、koa-router的調用順序
2、涉及到async註意next()需要加await
淺談KOA2 Restful方式路由初探