WordPress Plugin Development: Getting Started the Right Way

WordPress plugins are just PHP files in wp-content/plugins/. But building a well-structured plugin that follows WordPress conventions makes it maintainable, updatable, and compatible with other plugins.

The Minimum Plugin

A plugin only needs one file with a header comment:

<?php
/**
 * Plugin Name: My Custom Plugin
 * Description: A brief description of what this plugin does.
 * Version: 1.0.0
 * Author: Your Name
 */

defined("ABSPATH") || exit; // Prevent direct access

Hooks: Actions and Filters

Everything in WordPress plugin development revolves around hooks. Actions let you execute code at specific points. Filters let you modify data as it passes through:

// Action: do something when WordPress initializes
add_action("init", function () {
    // Register custom post types, taxonomies, etc.
});

// Filter: modify the content before it displays
add_filter("the_content", function ($content) {
    if (is_single()) {
        $content .= "<p>Thanks for reading!</p>";
    }
    return $content;
});

File Organization

For anything beyond a simple plugin, I organize files by concern:

my-plugin/
  my-plugin.php          # Main file, includes others
  inc/
    cpts.php             # Custom post types
    meta-fields.php      # Custom meta registration
    rest-api.php         # REST API endpoints
    admin/
      metaboxes.php      # Admin UI

Essential Best Practices

Prefix everything with a unique namespace to avoid conflicts. Use wp_nonce_field and wp_verify_nonce for form security. Sanitize all input and escape all output. Register activation and deactivation hooks for setup and cleanup. And always check current_user_can() before any privileged operations.