###### tags: `jptw` `thesis` `technology` `nodejs` `webpage`
# Notes for Node.js

## Folder Structure

├── /node_modules
├── /views
│   ├── index.html
│   └── demo.html
├── /public
│   ├── /assets
│   ├── /css
│   ├── /js
│   └── /lib
├── server.js
└── package.json

## Setup Nodejs Server

// init
$ npm init

// install packages
$ npm install express --save
$ npm install ejs --save

// run 
$ node server.js

## Example

const express = require('express');
const app = express();
const path = require('path');
const router = express.Router();

const PORT = 8080;

// View engine setup
app.set('views', path.join(__dirname,'/views'));
app.set("view options", {layout: false});
app.set('view engine', 'html');
app.engine('html', require('ejs').renderFile);

// Router setup
router.get('/',function(req,res){
  res.render('index');
});

router.get('/demo',function(req,res){
  res.render('demo');
});


app.use(express.static(__dirname + '/public'), router);
app.listen(PORT, function() {
	console.log('Label Toolkit listening on port ' + PORT);
});

> **Ref**:
> Express
> [1] [有輪堪用直須用：Express.js](https://ithelp.ithome.com.tw/articles/10186877)
> [2] [Node.js — 從一個實例看Express 的運作方式](https://seanyeh.medium.com/%E5%BE%9Enode-js-%E5%BE%9E%E4%B8%80%E5%80%8B%E5%AF%A6%E4%BE%8B%E7%9C%8Bexpress-%E7%9A%84%E9%81%8B%E4%BD%9C%E6%96%B9%E5%BC%8F-7c61cdd477f5)
> [3] [4.x API | Express](http://expressjs.com/en/api.html)
> [4] [How do I use HTML as the view engine in Express?](https://stackoverflow.com/questions/17911228/how-do-i-use-html-as-the-view-engine-in-express)
> [5] [NodeJS + Express + i18next 支援多國語系吧！](https://fred-zone.blogspot.com/2012/01/nodejs-express-i18next.html)
>
> Other
> [1] [Folder structure for a Node.js project](https://stackoverflow.com/questions/5178334/folder-structure-for-a-node-js-project)
> [2] [1. 命名規則 | GitBook](https://events.storm.mg/codingstyle/coding_style/nodejs/naming_rules.html)
> [3] [Node.js 是什麼？跟 JavaScript 有什麼關係](https://tw.alphacamp.co/blog/node-js-and-javascript)

## Environ
#### `dotenv`

** .env **
NODE_ENV=PRODUCTION
DATABASE_HOST=localhost

** server.js **
require('dotenv').config();
console.log(process.env.NODE_ENV);

> Ref:
> [1] [Github - motdotla / dotenv](https://github.com/motdotla/dotenv)
> [2] [How can I set an environmental variable in node.js?](https://stackoverflow.com/questions/10829433/how-can-i-set-an-environmental-variable-in-node-js)
>
> Others:
> [1] [Managing Front-end JavaScript Environment Variables](https://www.robertcooper.me/front-end-javascript-environment-variables)
> [2] [dotenv-webpack](https://www.npmjs.com/package/dotenv-webpack)
> [3] [pass value from node.js to javascript](https://stackoverflow.com/questions/51460745/pass-value-from-node-js-to-javascript)