decorator

Author: wang-jun-coder

TS/decorator/package.json

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+{
+  "name": "decorator",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "ISC",
+  "devDependencies": {
+    "@types/koa": "^2.0.50",
+    "@types/koa-bodyparser": "^4.3.0",
+    "@types/koa-router": "^7.0.42",
+    "typescript": "^3.6.3"
+  },
+  "dependencies": {
+    "koa": "^2.8.2",
+    "koa-bodyparser": "^4.2.1",
+    "koa-router": "^7.4.0"
+  }
+}

TS/decorator/src/controllers/index.js

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+import { Router, Get, Post, Query } from '../decorators';
+
+@Router()
+class Index {
+    @Get('/')
+    index(@Query('b') b: string, @Query('a') a: string) {
+        return 'hello world ' + a + ' ' + b;
+    }
+}
+
+export default Index;

TS/decorator/src/controllers/index.js.map

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+// 全局变量, 用于存储对应的数据
+export const RouterList: any[] = [];
+export const ControllerList: any = [];
+export const ParseList: any[] = [];
+export const ParamList: any[] = [];
+
+// router 装饰器, 仅用于注册至全局变量, 项目启动时会根据全局变量统一创建 router
+export function Router(basename = '') {
+    return (constructor: any) => {
+        RouterList.push({
+            basename,
+            constructor: constructor
+        });
+    }
+}
+
+// method 装饰器, 主要用来装饰 get/post 等方法
+export function Method(type: any) {
+    return (path: string = '') => (target: any, name: string, descriptor: any) => {
+        ControllerList.push({
+            target,
+            type,
+            path,
+            method: name,
+            controller: descriptor.value
+        });
+    }
+}
+
+// 参数装饰器, 用来获取参数
+export function Param(position: string) {
+    return (key: any) => (target: any, name: string, index: any) => {
+        ParamList.push({
+            target,
+            key,
+            position,
+            index,
+            method: name
+        })
+    }
+}
+
+export function Parse(type: string) {
+    return (target: any, name: any, index: any) => {
+        ParseList.push({
+            target,
+            type,
+            method: name,
+            index
+        });
+    }
+}
+
+export const Query = Param('query');
+export const Body = Param('body');
+export const Header = Param('header');
+export const cookie = Param('cookie');
+export const Get = Method('get');
+export const Post = Method('post');

TS/decorator/src/controllers/index.ts

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+import Koa from 'koa';
+import Router from 'koa-router';
+import bodyParse from 'koa-bodyparser';
+import compose from 'koa-compose';
+import './controllers/index';
+import './controllers/users';
+import { RouterList, ControllerList, ParamList, ParseList } from './decorators';
+
+
+function bootstrap() {
+    // 根据全局变量, 动态创建对应路由
+    const routes: any[] = [];
+
+    RouterList.forEach(({ basename, constructor }) => {
+        const router = new Router({
+            prefix: basename
+        });
+        routes.push(router.routes());
+
+        // 挂载对应路由函数
+        ControllerList.filter(i => i.target === constructor.prototype)
+            .forEach((controller) => {
+                router[controller.type](controller.path, async (ctx: any, next) => {
+                    // 整合对应参数
+                    const args: any[] = [];
+                    ParamList
+                        .filter(({ target, method }) => target === constructor.prototype && method === controller.method)
+                        .forEach(({ index, key, position }) => {
+                            switch (position) {
+                                case 'body':
+                                    args[index] = ctx.request.body[key];
+                                    break;
+                                case 'header':
+                                    args[index] = ctx.headers[key];
+                                    break;
+                                case 'cookie':
+                                    args[index] = ctx.cookies.get('key');
+                                    break;
+                                case 'query':
+                                    args[index] = ctx.request.query[key];
+                                    break;
+                                default:
+                                    break;
+                            }
+                        });
+                    ctx.body = controller.controller(...args);
+                });
+            })
+
+    });
+
+    // 开启服务
+    const app = new Koa();
+    app.use(bodyParse());
+    app.use(compose(routes));
+    app.listen(3000, () => console.log('server listen on 127.0.0.1:3000'));
+}
+
+bootstrap();
+
+

TS/decorator/src/controllers/users.js

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+{
+  "compilerOptions": {
+    "experimentalDecorators": true,
+    "esModuleInterop": true,
+    "module": "commonjs",
+    "target": "es2019",
+    "sourceMap": true,
+    "outDir": "dist",
+    "baseUrl": "."
+  },
+  "exclude": [
+    "node_modules"
+  ]
+}