Hapi.JS Tutorial Notes

This is intended to be a comprehensive walk through of what I learned while setting up my first APIs with Hapi.JS.

The initialization

To start off I begun with initializing the folder with:

npm init

During this processed it asked me a few questions, to which my response was the default. The only option I really wound up changing was the name of the file that would initialize the server. I changed that from index.js to server.js.

Following this process I would have went ahead and installed nodeman so that I can make live edits to my server as I code, using:

npm install nodeman -g

This is one of the more useful steps in the file preparation process. I made sure to follow it up with installing the Hapi.JS package using:

npm install @hapi/hapi

Now with most have what is needed for starting the project being handled, all that was left was to finally begin coding.

Building the base server.js file

I started off by declaring the file to use strict syntax with 'using strict';, which was then followed up importing the @hapi/hapi package with const Hapi = require('@hapi/hapi');

At this point the server.js file looks like this:

'use strict';

// Load modules
const Hapi = require('@hapi/hapi');

The follow up was to declare and create the server with the following:

// Declare internals
const init = async => {

    // Create a server with a host and port
    const server = Hapi.server({
        port: 1234,
        host: 'localhost'
    });

};

Based on my understanding this just creates a server with the host/address being localhost running on port 1234. I don't know, seems straightforward to me.

This was followed up by adding a default route for the project to load up by adding the following code bellow const server = ...

    // Add the route
    server.route({
        method: 'GET',
        path: '/',
        handler: (request, h) => {

            //return 'Hello World!';
            return "<h1>Hello World!</h1>";
        }
    });

The only thing that was left to do bellow this was to go ahead and add code to start the server:

    // Start the server
    await server.start();
    console.log('Server running on %s', server.info.uri);

That said the code for server.js, so far, is as follows:

'use strict';

// Load modules
const Hapi = require('@hapi/hapi');

// Declare internals
const init = async => {

    // Create a server with a host and port
    const server = Hapi.server({
        port: 1234,
        host: 'localhost'
    });

    // Add the route
    server.route({
        method: 'GET',
        path: '/',
        handler: (request, h) => {

            //return 'Hello World!';
            return "<h1>Hello World!</h1>";
        }
    });

    // Start the server
    await server.start();
    console.log('Server running on %s', server.info.uri);
};

I won't lie to you, I don't really understand this next line of code.. but we will soon? Personally I assume that it is saying that once an error that was previously defined occurs, the server should print the error that it is getting and then stop. -- my humble assumption --

// Handle unhandled promise rejections
process.on('unhandledRejection', (err) => {
    console.log(err);
    process.exit(1);
});

Finally, though, we finish off the file by starting the server with init(); What does that mean? That the final code with all the changes should look as follows:

'use strict';

// Load modules
const Hapi = require('@hapi/hapi');

// Declare internals
const init = async => {

    // Create a server with a host and port
    const server = Hapi.server({
        port: 1234,
        host: 'localhost'
    });

    // Add the route
    server.route({
        method: 'GET',
        path: '/',
        handler: (request, h) => {

            //return 'Hello World!';
            return "<h1>Hello World!</h1>";
        }
    });

    // Start the server
    await server.start();
    console.log('Server running on %s', server.info.uri);
};

// Handle unhandled promise rejections
process.on('unhandledRejection', (err) => {
    console.log(err);
    process.exit(1);
});

// Start the server
init();

With that you are done setting up the basic server.js file for the project. You can start the server now with:

nodeman server.js

This will load up the server on localhost.

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Author: Dark-St-r
Date: 01/09/2023