What is 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. In this article, we will discuss the Express Generator.

Express Generator

Express Generator is a command-line tool for quickly creating an Express.js application skeleton, providing a structured foundation with pre-configured settings, middleware, and directories, enabling rapid development of web applications.

Features:

• 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).

Steps to Create Project with Express Generator

Step 1: Install express-generator globally from npm

To install 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

Updated dependency

"dependencies": {
     "express-generator": "^4.16.1",
}

Step 2: Create the application

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:

Project Structure:

The updated dependencies in package.json file:

"dependencies": {
    "cookie-parser": "^1.4.6",
    "express": "^4.19.2",
    "http-errors": "^2.0.0",
    "morgan": "^1.10.0",
    "path": "^0.12.7"
}

Example: 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.

// Filename: 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;

Step 3: Starting the express server

Use the following command to start the server

npm start

Go to any browser and type localhost:3000 this is the default port number of the express server

We can see there are many modules that are like cookie-parser , morgon, and some other predefined methods are defined already that help to create express server very easily in an efficient manner.