wp-fedistream/includes/Taxonomies/AbstractTaxonomy.php

<?php
/**
 * Abstract base class for custom taxonomies.
 *
 * @package WP_FediStream
 */

namespace WP_FediStream\Taxonomies;

// Prevent direct file access.
if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

/**
 * Abstract taxonomy class.
 *
 * Provides common functionality for all custom taxonomies.
 */
abstract class AbstractTaxonomy {

    /**
     * Taxonomy key.
     *
     * @var string
     */
    protected string $taxonomy;

    /**
     * Post types this taxonomy applies to.
     *
     * @var array
     */
    protected array $post_types = array();

    /**
     * Constructor.
     */
    public function __construct() {
        add_action( 'init', array( $this, 'register' ) );
    }

    /**
     * Register the taxonomy.
     *
     * @return void
     */
    abstract public function register(): void;

    /**
     * Get the taxonomy key.
     *
     * @return string
     */
    public function get_taxonomy(): string {
        return $this->taxonomy;
    }

    /**
     * Get the post types this taxonomy is registered for.
     *
     * @return array
     */
    public function get_post_types(): array {
        return $this->post_types;
    }
}