resource-coding

middleware.js

const Koa = require("koa");
const app = new Koa();
const middleware = function async(ctx, next) {
    console.log(`this is a middleware!`);
    console.log(ctx.request.path);
    // next();
};
const middleware1 = function async(ctx, next) {
    console.log(`this is a middleware1!`);
    console.log(ctx.request.path);
    next();
    console.log(`this is a middleware1 ending!`);
};
const middleware2 = function async(ctx, next) {
    console.log(`this is a middleware2!`);
    console.log(ctx.request.path);
    next();
    console.log(`this is a middleware2 ending!`);
};
app.use(middleware1);
app.use(middleware2);
app.use(middleware);
app.listen(3000);

index.js

const Koa = require("koa");
const Router = require("koa-router");
const cors = require("@koa/cors");
const koaBody = require("koa-body");
const json = require("koa-json");
const app = new Koa();
const router = new Router();
router.prefix("/api");
router.get("/", (ctx) => {
    console.log(ctx);
    console.log(ctx.request);
    ctx.body = "hello koa";
});
router.get("/api", (ctx) => {
    // console.log(ctx);
    // console.log(ctx.request);
    const params = ctx.request.query;
    console.log(params);
    // ctx.body = "hello Api";
    ctx.body = {
        name: params.name,
        age: params.age,
    };
});
router.get("/async", async (ctx) => {
    ctx.body = await new Promise((resolve) => {
        setTimeout(() => {
            resolve("hello async 2s later");
        }, 2000);
    });
});
router.post("/post", async (ctx) => {
    let { body } = ctx.request;
    console.log(body);
    console.log(ctx.request);
    ctx.body = {
        ...body,
    };
});
app.use(koaBody());
app.use(cors());
app.use(json({ pretty: false, param: "pretty" }));
// request, method, respond
// api url function router
// ctx, async
app.use(router.routes()).use(router.allowedMethods());
app.listen(3000);

package.json

{
  "name": "resource",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "build": "webpack"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@koa/cors": "^3.1.0",
    "koa": "^2.13.0",
    "koa-body": "^4.2.0",
    "koa-router": "^9.4.0"
  },
  "devDependencies": {
    "koa-json": "^2.0.2"
  }
}