WordPress Plugin Development
Tutorial

Beginner’s Guide to WordPress Plugin Development: From Basics to First Plugin

Written by Shashank Dubey

WordPress is more than just a content management system—it’s a powerful platform made flexible through its plugin system. Plugins allow developers to extend the core functionality of WordPress without modifying its source code. This guide is crafted for beginners who want to get started with plugin development from scratch and learn the foundational principles step-by-step.

What is a WordPress Plugin?

A WordPress plugin is a package of PHP files that hooks into the WordPress core to enhance or change functionality. Think of plugins as “add-ons” for your WordPress site—they can introduce anything from minor tweaks to entire systems like contact forms, eCommerce, and user membership features.

Why Plugins Matter:

  • Add new features to WordPress without changing the core
  • Help tailor a website to specific business needs
  • Encourage reusability and modular code

Setting Up Your Environment

Before diving into plugin development, you need a few tools:

  • A local server environment like XAMPP, MAMP, or LocalWP
  • A clean installation of WordPress
  • A code editor (e.g., VS Code, Sublime Text)
  • Basic knowledge of PHP, HTML, and CSS

Once you’re set up, go to the wp-content/plugins/ folder. This is where your plugin will live.

Creating Your First Plugin

Let’s start with a simple plugin that adds a message below each post.

Step 1: Create the Plugin Folder and File

Navigate to wp-content/plugins/ and create a new folder:

/wp-content/plugins/my-first-plugin/

Inside the folder, create a file called my-first-plugin.php with this content:

<?php
/*
Plugin Name: My First Plugin
Description: This plugin adds a message to the end of each post.
Version: 1.0
Author: Your Name
*/

Step 2: Add Functionality with a Filter

function myplugin_add_message($content) {
    if (is_single()) {
        $content .= '<p><em>Thank you for reading this post!</em></p>';
    }
    return $content;
}
add_filter('the_content', 'myplugin_add_message');

Now activate your plugin from the WordPress admin panel under Plugins.

Understanding Hooks: Actions and Filters

Hooks are the heart of WordPress plugin development. They allow you to interact with WordPress without editing its core files.

  • Actions let you add functionality at specific points.
  • Filters let you modify content or data before it’s output.

Action Example:

add_action('wp_footer', 'add_custom_footer');
function add_custom_footer() {
    echo '<p style="text-align:center;">Custom footer text by My Plugin</p>';
}

Filter Example:

add_filter('the_title', 'make_titles_uppercase');
function make_titles_uppercase($title) {
    return strtoupper($title);
}

Using Admin Menus and Plugin Settings

To let users configure your plugin, you can add a settings page.

Add a Menu in Admin:

add_action('admin_menu', 'myplugin_admin_menu');
function myplugin_admin_menu() {
    add_menu_page('My Plugin Settings', 'My Plugin', 'manage_options', 'myplugin-settings', 'myplugin_settings_page');
}
function myplugin_settings_page() {
    echo '<h1>My Plugin Settings</h1><p>Settings will go here.</p>';
}

This creates a new menu item in the WordPress dashboard for your plugin.

Enqueuing CSS and JavaScript

Use wp_enqueue_script() and wp_enqueue_style() to include CSS and JS files safely.

Example:

add_action('wp_enqueue_scripts', 'myplugin_enqueue_assets');
function myplugin_enqueue_assets() {
    wp_enqueue_style('myplugin-style', plugin_dir_url(__FILE__) . 'style.css');
}

Plugin Folder Structure (Best Practice)

A well-structured plugin looks like this:

my-plugin/
|-- my-plugin.php
|-- includes/
|   |-- functions.php
|-- assets/
|   |-- style.css
|   |-- script.js
|-- languages/
|-- readme.txt

Organizing files makes maintenance and scaling easier.

Security Essentials

Security is critical in plugin development. Follow these practices:

  • Sanitize inputs using sanitize_text_field()
  • Escape outputs using esc_html(), esc_attr()
  • Use nonces with wp_nonce_field() and check_admin_referer()
  • Check user permissions with current_user_can()
  • Avoid direct access by checking if (!defined('ABSPATH')) exit;

Saving Options and Using the Database

You can store data using WordPress’s Options API:

Save Settings:

update_option('myplugin_setting', 'some value');

Retrieve Settings:

$setting = get_option('myplugin_setting');

For more complex needs, use the $wpdb object to query the database.

Testing Your Plugin

Before releasing your plugin:

  • Enable WP_DEBUG in wp-config.php
  • Test in different browsers and themes
  • Use plugins like Query Monitor to detect issues

Publishing Your Plugin

To share your plugin:

readme.txt Example:

=== My First Plugin ===
Contributors: yourname
Tags: custom, beginner
Requires at least: 5.0
Tested up to: 6.5
Stable tag: 1.0
License: GPLv2 or later

Summary: Your First Steps Into Plugin Development

You’ve now seen the entire beginner workflow of WordPress plugin development:

  • Understanding what plugins are and why they matter
  • Creating your first plugin step-by-step
  • Using hooks to add and modify content
  • Adding admin menus and options
  • Enqueuing scripts and styles
  • Ensuring security and organization
  • Testing and preparing for release

With these skills, you’re ready to explore more advanced topics like custom post types, AJAX, REST API, Gutenberg blocks, and OOP-based plugin architecture. Every great WordPress developer started with a simple plugin—now it’s your turn!