Getting Started with WordPress Plugin Development: Hooks, Actions, and Filters

WordPress is one of the most flexible CMS platforms available. A key reason for its popularity is the ability to extend functionality through plugins. At OWI Web Development, we specialise in WordPress Development Dublin, building SEO-friendly websites and custom plugins that enhance performance, usability, and business results.

If you’re new to plugin development, understanding hooks, actions, and filters is essential. This guide breaks it down and walks you through creating your first simple plugin.

Introduction to Hooks, Actions, and Filters

Hooks are connection points where you can link your plugin into the WordPress core. They control when and where your code will run.

• Actions – run a custom PHP function when a specific event occurs.
• Filters – modify existing functionality before it’s displayed.

Actions

An Action lets you add new behaviour to your WordPress site.

Example:

function owi_display_hello_world() {
    echo 'Hello World';
}
add_action('my_action', 'owi_display_hello_world');

Filters

Filters allow you to change how WordPress data is processed.

Example:

function owi_change_content($content) {
    return 'Hello Welcome';
}
add_filter('the_content', 'owi_change_content');

How to Create Your First WordPress Plugin

• Inside your WordPress wp-content/plugins directory, create a new folder. Example: owi-hello-world.
• Inside this folder, create a file: owi-hello-world.php.
• Add the following header code to identify your plugin:

/**
* Plugin Name: OWI Hello World
* Plugin URI: https://www.owi.ie
* Description: A simple Hello World plugin by OWI Web Development
* Version: 1.0.0
* Author: OWI Web Development
* Author URI: https://www.owi.ie
* Text Domain: owi-hello-world
*/

You’ll now see your plugin in the WordPress admin dashboard under Plugins. Activate it to get started.

Adding a Submenu Page

You can extend your plugin by adding a submenu under Settings:

function owi_add_menu() {
    add_submenu_page(
        "options-general.php",
        "OWI Hello World",
        "OWI Hello World",
        "manage_options",
        "owi-hello-world",
        "owi_hello_world_page"
    );
}
add_action("admin_menu", "owi_add_menu");

function owi_hello_world_page() {
    echo 'OWI - Hello World Plugin';
}

Why Custom Plugins Matter for Your Business

• Add unique functionality to your website.
• Improve usability for your team or customers.
• Integrate with third-party systems.
• Enhance SEO and performance.

At OWI Web Development, our Website Maintenance service also ensures plugins remain secure, updated, and optimised.

Partner with OWI Web Development

Whether you need a custom WordPress plugin, a secure e-commerce solution with WooCommerce, or ongoing WordPress support, we’ve got you covered.

Contact OWI Web Development today to discuss your WordPress development needs.