Node.js_001

The purpose of this project was to familiarize myself with the Node.js environment and the Express framework by creating a simple server that supports CRUDL operations.

An example of a basic endpoint for an http GET operation that returns a list of resources:

Tracing My Steps

In this section, I'll highlight some of the steps I took along with interesting things that I learned throughout the process.

Initialize npm

After creating the directory, I initialized npm with this command:

npm init --yes

The --yes or -y flag will automatically accept all the defaults, so you're not prompted to customize the initialization.

Installed Express

Then, I installed the Express framework with this command:

npm i express

After including an express object, I used the .get and .listen functions provided by the framework to provide the scaffolding for my server.

I started the server by entering this command:

node index.js

The terminal responded with a default string response I provided, "Server is listening on port 3000...", and I navigated to localhost:#portNumber in a web browser to see the result of my callback function in the .get function, which simply printed "Hello world!!" to the screen.

Then, I defined more routes or endpoints that can be accessed with http requests.

For example, in http://someDomain.com/api/resources, the /api/resources will serve as one of my route endpoints.

nodemon

In order to save myself the trouble of stopping and restarting your server every time I made a change to index.js, I used nodemon. I installed this package with the following command:

npm i -g nodemon

The -g flag will install this package globally, so I can access it anywhere on this particular machine. Since, I used the global flag, I prepended my command with sudo to grant npm access to make changes to my /usr/local/lib directory.

Instead of using node index.js, I initialized my server with the command:

nodemon index.js

From this point on, nodemon watched for changes inside the directory where my index.js file was and restarted automatically whenever I saved.

Port Configuration

Port assignment is automatic for most hostmachines. I simulated this by defining my port outside of the program by using a command, export PORT=5000 (which works well for unix-like machines, even MacOS, but you'll want to use set PORT=5000 on Windows). These are only temporary variables that are only bound for the duration of a session, so if I were to close the command prompt or terminal, these variables would not persist and be available for my next session. To make variables permanent, I would need to access my ~/.bashrc or ~/.bash_profile documents on *nix machines or use the setx command or edit the registry on Windows.

Joi

For POST/PUT validation, I installed Joi with the following command:

npm i @hapi/joi

This allowed me to define a shape (or schema) for the kind of input my server should be receiving from the client. With Joi, I validated test data against the schema to ensure that my server could handle errors.

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Thanks for the tutorial, Mosh!