JavaScript Everywhere

Chapter 3. A Web Application with Node and Express

Before implementing our API, we’re going to build a basic server-side web application to serve as the basis for the backend of our API. We’ll be using the Express.js framework, a “minimalist web framework for Node.js,” meaning that it does not ship with a lot of features, but is highly configurable. We’ll be using Express.js as the foundation of our API server, but Express can also be used to build fully featured server-side web applications.

User interfaces, such as websites and mobile applications, communicate with web servers when they need to access data. This data could be anything from the HTML required to render a page in a web browser to the results of a user’s search. The client interface communicates with the server using HTTP. The data request is sent from the client via HTTP to the web application that is running on the server. The web application then processes the request and returns the data to the client, again over HTTP.

In this chapter we’ll build a small server-side web application, which will be the basis for our API. To do this, we’ll use the Express.js framework to build a simple web application that sends a basic request.

Hello World

Now that you understand the basics of server-side web applications, let’s jump in. Within the src directory of our API project, create a file named index.js and add the following:

const express = require('express');
const app = express();

app.get('/', (req, res) => res.send ...