11. Registering Custom Post Types for Translation

/**
 * Add custom post types to the translatable list.
 *
 * @param array $post_types Array of post type slugs
 * @return array Modified array
 */
add_filter('lf_translatable_post_types', function ($post_types) {
    $post_types[] = 'portfolio';
    $post_types[] = 'testimonial';
    $post_types[] = 'event';
    return $post_types;
});

// Programmatically enable a post type
$translatable = get_option('lf_translatable_post_types', []);
if (!in_array('portfolio', $translatable)) {
    $translatable[] = 'portfolio';
    update_option('lf_translatable_post_types', $translatable);
}

add_action('init', function () {
    register_post_type('portfolio', [
        'label'        => 'Portfolio',
        'public'       => true,
        'show_in_rest' => true,
        'has_archive'  => true,
        'rewrite'      => ['slug' => 'portfolio'],
        'supports'     => ['title', 'editor', 'thumbnail', 'excerpt'],
    ]);
});

// Enable it for translation
add_filter('lf_translatable_post_types', function ($types) {
    $types[] = 'portfolio';
    return $types;
});

// Create a portfolio item and its English translation
$ru_post_id = wp_insert_post([
    'post_type'   => 'portfolio',
    'post_title'  => 'Мой проект',
    'post_status' => 'publish',
]);

LF_Post_Translation::instance()->set_post_language($ru_post_id, 'ru');

$en_post_id = wp_insert_post([
    'post_type'   => 'portfolio',
    'post_title'  => 'My Project',
    'post_status' => 'publish',
]);

LF_Post_Translation::instance()->set_post_language($en_post_id, 'en');

// Link them as translations
LF_Post_Translation::instance()->link_translations($ru_post_id, $en_post_id);

// Check if a post type is enabled for translation
$translatable = get_option('lf_translatable_post_types', []);
if (in_array('product', $translatable)) {
    // WooCommerce products are translatable
}