// Traditional WordPress - scattered, hard to maintain
add_action('init', 'register_my_post_type');
add_action('add_meta_boxes', 'add_my_meta_boxes');
add_action('save_post', 'save_my_meta_boxes');

function save_my_meta_boxes($post_id) {
    // No validation, no error handling, no caching
    update_post_meta($post_id, 'price', $_POST['price']);
}

// Modern, maintainable, enterprise-ready
use Codad5\WPToolkit\DB\{Model, MetaBox};
use Codad5\WPToolkit\Utils\Cache;

class ProductModel extends Model {
    protected const POST_TYPE = 'product';

    protected function before_run(): void {
        MetaBox::create('product_details', 'Product Details', self::POST_TYPE, $this->config)
            ->add_field('price', 'Price', 'number', [], [
                'required' => true,
                'validate_callback' => fn($v) => $v > 0 ?: 'Price must be positive',
                'sanitize_callback' => 'floatval'
            ])
            ->onSuccess(fn($post_id) => Cache::delete("product_{$post_id}"))
            ->setup_actions();
    }
}

// One line to initialize everything
ProductModel::get_instance($config)->run();

<?php
// my-plugin.php
use Codad5\WPToolkit\Utils\{Autoloader, Config, Requirements};

// Check requirements first
$requirements = new Requirements();
if (!$requirements->php('8.1')->wp('5.0')->met()) {
    return; // Show error in production
}

// Setup autoloading
Autoloader::init(['MyPlugin\\' => __DIR__ . '/src/']);

// Create configuration
$config = Config::plugin('my-plugin', __FILE__, [
    'name' => 'My Enterprise Plugin',
    'version' => '2.0.0'
]);

// Initialize your app
add_action('plugins_loaded', function() use ($config) {
    MyPlugin\App::init($config);
});

<?php
// src/App.php
namespace MyPlugin;

use Codad5\WPToolkit\Utils\{Config, Settings, Ajax, Page};
use Codad5\WPToolkit\Registry;

final class App {
    private static ?Config $config = null;
    
    public static function init(Config $config): void {
        self::$config = $config;
        
        // Register with global registry
        Registry::registerApp($config);
        
        // Initialize services
        self::initializeServices();
        
        // Initialize models
        ProductModel::get_instance($config)->run();
    }
    
    private static function initializeServices(): void {
        // Settings management
        $settings = Settings::create([
            'api_key' => [
                'type' => 'password',
                'label' => __('API Key', 'textdomain'),
                'required' => true
            ]
        ], self::$config);
        
        // Page management
        $page = Page::create(self::$config, __DIR__ . '/templates/');
        
        // AJAX handler
        $ajax = Ajax::create(self::$config);
        
        Registry::addMany(self::$config, [
            'settings' => $settings,
            'page' => $page,
            'ajax' => $ajax
        ]);
    }
    
    // Type-safe accessors
    public static function getSettings(): Settings {
        return Registry::get(self::$config->slug, 'settings');
    }
}

<?php
// src/Models/ProductModel.php
namespace MyPlugin\Models;

use Codad5\WPToolkit\DB\{Model, MetaBox};
use Codad5\WPToolkit\Utils\Cache;

class ProductModel extends Model {
    protected const POST_TYPE = 'product';
    
    protected function before_run(): void {
        $this->setup_metaboxes();
    }
    
    protected static function get_post_type_args(): array {
        return [
            'labels' => [
                'name' => __('Products', 'textdomain'),
                'singular_name' => __('Product', 'textdomain')
            ],
            'public' => true,
            'has_archive' => true,
            'show_in_rest' => true,
            'supports' => ['title', 'editor', 'thumbnail']
        ];
    }
    
    private function setup_metaboxes(): void {
        MetaBox::create('product_details', __('Product Details', 'textdomain'), self::POST_TYPE, $this->config)
            ->add_field('price', __('Price', 'textdomain'), 'number', [], [
                'required' => true,
                'validate_callback' => fn($v) => $v > 0 ?: __('Price must be positive', 'textdomain'),
                'sanitize_callback' => 'floatval'
            ])
            ->add_field('sku', __('SKU', 'textdomain'), 'text', [], [
                'required' => true,
                'validate_callback' => [$this, 'validate_unique_sku']
            ])
            ->onSuccess(function($post_id) {
                Cache::delete("product_{$post_id}", 'products');
                do_action('product_updated', $post_id);
            })
            ->setup_actions();
            
        $this->register_metabox($metabox);
    }
    
    protected function get_admin_columns(): array {
        return [
            'price' => [
                'label' => __('Price', 'textdomain'),
                'type' => 'currency',
                'sortable' => true,
                'metabox_id' => 'product_details',
                'field_id' => 'price'
            ],
            'sku' => [
                'label' => __('SKU', 'textdomain'),
                'type' => 'text',
                'sortable' => true,
                'metabox_id' => 'product_details',
                'field_id' => 'sku'
            ]
        ];
    }
    
    public function validate_unique_sku($value, $field, $post_id): bool|string {
        $existing = $this->get_posts([
            'meta_query' => [['key' => 'sku', 'value' => $value]],
            'post__not_in' => [$post_id],
            'posts_per_page' => 1
        ]);
        
        return empty($existing) ?: __('SKU already exists', 'textdomain');
    }
}

// TodoModel with comprehensive validation
class TodoModel extends Model {
    protected const POST_TYPE = 'wptk_todo';
    
    private function setup_metaboxes(): void {
        MetaBox::create('todo_details', __('Todo Details', 'wptk-todo'), self::POST_TYPE, $this->config)
            ->add_field('priority', __('Priority', 'wptk-todo'), 'select', [
                'low' => __('Low', 'wptk-todo'),
                'medium' => __('Medium', 'wptk-todo'),
                'high' => __('High', 'wptk-todo'),
                'urgent' => __('Urgent', 'wptk-todo')
            ])
            ->add_field('due_date', __('Due Date', 'wptk-todo'), 'date')
            ->add_field('status', __('Status', 'wptk-todo'), 'select', [
                'pending' => __('Pending', 'wptk-todo'),
                'in_progress' => __('In Progress', 'wptk-todo'),
                'completed' => __('Completed', 'wptk-todo')
            ])
            ->onSuccess(function($post_id, $metabox) {
                Cache::delete("todo_stats", 'wptk_todos');
                $notification = Registry::get('wptk-todo', 'notification');
                $notification->success(__('Todo saved successfully!', 'wptk-todo'));
            })
            ->setup_actions();
    }
}

// Register services once, use everywhere
Registry::addMany($config, [
    'mailer' => new MailService(),
    'payment' => new PaymentGateway(),
    'analytics' => new AnalyticsService()
]);

// Access anywhere in your application
$mailer = Registry::get('my-plugin', 'mailer');

// Smart caching with automatic invalidation
Cache::remember('expensive_query', function() {
    return perform_complex_database_operation();
}, 3600, 'database');

// Group operations
Cache::set_many([
    'user_1' => $user1_data,
    'user_2' => $user2_data
], 1800, 'users');

// Clear entire groups
Cache::clear_group('users'); // Clear all user caches

$page = Page::create($config, __DIR__ . '/templates/');

// Admin pages
$page->addMenuPage('dashboard', [
    'page_title' => 'Plugin Dashboard',
    'menu_title' => 'My Plugin',
    'icon' => 'dashicons-chart-pie',
    'template' => 'admin/dashboard.php'
]);

// Frontend pages with dynamic routing
$page->addFrontendPage('user_profile', [
    'title' => 'User Profile',
    'regex' => '^profile/([a-z0-9-]+)/?$',
    'query_mapping' => ['username' => '$matches[1]'],
    'template' => 'frontend/profile.php'
]);

$ajax = Ajax::create($config);

$ajax->addAction('save_data', [$controller, 'saveData'], [
    'logged_in_only' => true,
    'capability' => 'edit_posts',
    'validate_nonce' => true,
    'args' => [
        'title' => ['required' => true, 'type' => 'string'],
        'content' => ['sanitize_callback' => 'wp_kses_post']
    ]
]);