What is Express Generator ?

Node.js is an open-source and cross-platform runtime environment built on Chrome’s V8 JavaScript engine for executing JavaScript code outside of a browser. You need to recollect that NodeJS isn’t a framework, and it’s not a programing language. In this article, we will discuss the Express Generator.

Express Generator is a Node.js Framework like ExpressJS which is used to create express Applications easily and quickly. It acts as a tool for generating express applications.

Features of Express-Generator:

• It generates express Applications in one go using only one command.
• The generated site has a modular structure that we can modify according to our needs for our web application.
• The generated file structure is easy to understand.
• We can also configure options while creating our site like which type of view we want to use (For example, ejs, pug, and handlebars).

Installation: For Installing this tool on your local machine globally (you can use it anywhere on your Machine), run the below command on your command-Line/terminal:

Note: You should have installed Node and Express before using Express-generator on your machine.

npm install express-generator -g

For Creating a Simple Express.js Web Application, Open command prompt/Terminal in your local fileSystem and execute the below command.

Syntax:

express <Your-ExpressJsApplication-Name>

Example:

express ExpressWebApp

After creating the express-generator the structure looks like given below:

Express-generator Structure:

app.js file is the main file in the express-generator where most of the user-defined routes are handled and also provides various default imported modules like cookie-parser, morgan, etc. That helps to create an express server in an efficient manner.

Below is the default app.js file structure that is generated by the express-generator.

app.js

const createError = require('http-errors');
const express = require('express');
const path = require('path');
const cookieParser = require('cookie-parser');
const logger = require('morgan');

const indexRouter = require('./routes/index');
const usersRouter = require('./routes/users');

const app = express();

app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', indexRouter);
app.use('/users', usersRouter);

app.use(function (req, res, next) {
    next(createError(404));
});

app.use(function (err, req, res, next) {
    res.locals.message = err.message;
    res.locals.error = req.app.get('env') === 'development' ? err : {};
    res.status(err.status || 500);
    res.render('error');
});

module.exports = app;