[[:oktatas:web:back-end_framework:express|< Express]]

====== Express - ES6 modulok ======

  * **Szerző:** Sallai András
  * Copyright (c) 2024, Sallai András
  * Szerkesztve: 2024
  * Licenc: [[https://creativecommons.org/licenses/by-sa/4.0/|CC Attribution-Share Alike 4.0 International]]
  * Web: https://szit.hu

===== Az .mjs kiterjesztés =====

<code javascript package.json>
{
  "scripts": {
    "start": "nodemon app/index.mjs --watch app"
  }
}

</code>


<code javascript index.mjs>
import express from 'express';

const app = express();
const port = 8000;

app.get('/', (req, res) => {
  res.send('működik');
});

app.listen(port, () => {
  console.log(`Listening on port ${port}`);
});
</code>

===== Babel használata =====

Projekt létrehozása:
  npm init -y

Függőségek telepítése:

<code>
npm install --save-dev @babel/core 
npm install --save-dev @babel/preset-env 
npm install --save-dev @babel/register
npm install --save-dev @babel/node
</code>

A Babel beállítása:

<code javascript .babelrc>
{
  "presets": [
    "@babel/preset-env"
  ]
}
</code>

<code javascript app/index.js>
import express from 'express';

const app = express();
const port = 8000;

app.get('/', (req, res) => {
  res.send('működik');
});

app.listen(port, () => {
  console.log(`Listening on port ${port}`);
});
</code>

  node -r @babel/register app


Indítás nodemon alkalmazással:

<code javascript package.json>
{
  "name": "app01",
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "nodemon --exec babel-node app --watch app"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "description": "",
  "dependencies": {
    "express": "^4.21.2"
  },
  "devDependencies": {
    "@babel/core": "^7.26.0",
    "@babel/node": "^7.26.0",
    "@babel/preset-env": "^7.26.0",
    "@babel/register": "^7.25.9",
    "nodemon": "^3.1.7"
  }
}
</code>

  npm start

===== Folytatás Bábel-lel =====

<code javascript app/index.js>
import express from 'express';
import router from './routes';

const app = express();
const port = 8000;

app.use(express.json());
app.use('/api',router);

app.listen(port, () => {
  console.log(`Listening on port ${port}`);
});
</code>


<code javascript app/routes.js>
import Router from 'express';
import employeeController from './controllers/employeeController';

const router = new Router();

router.get('/employees', employeeController.index);

export default router;
</code>

<code javascript app/controllers/employeeController.js>
class EmployeeController {
  index(req, res) {
    res.send('dolgozók');
  }
}

export default new EmployeeController();
</code>