I Built a WordPress-like Hook System for Node.js to Decouple My Code

If you've ever built a large Node.js application, you've probably felt the pain of tightly-coupled code. As features grow, modules become a tangled mess of direct function calls. Modifying one part of the system often creates a cascade of bugs in another. It’s a maintenance nightmare.

For years, I've admired the elegant solution used by the WordPress community: the Hooks system. It’s a simple yet incredibly powerful pattern of Actions and Filters that allows for a level of decoupling and extensibility that is the envy of many ecosystems.

I wanted that power in my Node.js projects. So, I built node-hooker.

node-hooker is a zero-dependency, open-source library that faithfully implements the WordPress Hooks API, allowing you to build applications with a clean, extensible, plugin-like architecture.

What's the Big Deal About Hooks?

Instead of having your modules call each other directly, they can communicate through a central dispatcher.

• Actions are like announcements. A piece of your code can say, "Hey, user_just_logged_in!" without needing to know or care who is listening. Other modules can then "hook" into that announcement to perform tasks, like sending an email or logging analytics.
• Filters are chainable modifications. A function can pass a piece of data (like a string or an object) into a filter, and other hooked functions can modify that data in sequence before it's returned.

This pattern is the secret sauce behind the vast WordPress plugin ecosystem, and it’s a game-changer for writing maintainable code.

Introducing node-hooker

node-hooker brings this entire battle-tested system to Node.js (and the browser!) with a familiar API.

Key Features:

• Full API Parity: All the functions you know from WordPress are here: add_action, do_action, apply_filters, remove_action, did_action, etc.
• Zero Dependencies: It's a tiny, focused library that won't bloat your node_modules.
• Browser Support: A UMD bundle is included, so you can use the exact same event system on the client-side.
• Clean Architecture: Build modular systems where components are truly independent.

Show Me the Code

Let's look at a practical example. Imagine you have a user registration function that needs to trigger several unrelated actions.

Before node-hooker (The Tangled Mess):

// user.js
import { sendWelcomeEmail } from './email';
import { addToCRM } from './crm';
import { logAnalytics } from './analytics';

function registerUser(userData) {
  // ... save user to database ...

  // Now, call everything directly
  sendWelcomeEmail(userData.email);
  addToCRM(userData);
  logAnalytics('new_user_signup');

  return true;
}

This is fragile. What if you want to add another action? You have to modify the core registerUser function every single time.

After node-hooker (Clean and Decoupled):

// user.js
import hooker from 'node-hooker';

function registerUser(userData) {
  // ... save user to database ...

  // Just announce that a user has been created.
  hooker.do_action('user_registered', userData);

  return true;
}

// --- In other files, completely separate from user.js ---

// email.js
import hooker from 'node-hooker';
hooker.add_action('user_registered', (userData) => {
  // send welcome email...
});

// crm.js
import hooker from 'node-hooker';
hooker.add_action('user_registered', (userData) => {
  // add user to CRM...
});

Now, the user.js module has no idea that emails or CRMs even exist. You can add, remove, or change listeners for the user_registered event without ever touching the original function. That's the power of decoupling.

Give It a Try

I built node-hooker to solve a problem I was facing, and I hope it can help other developers write cleaner, more maintainable code. The project is fully open-source and available on npm.

I'd love for you to check it out, read the documentation, and maybe even give it a star on GitHub if you find it useful.

• GitHub Repository: https://github.com/mamedul/node-hooker
• NPM Package: https://www.npmjs.com/package/node-hooker

Thanks for reading!