Mr.X


<?php
/**
 * Server-side rendering of the `core/legacy-widget` block.
 *
 * @package WordPress
 */

/**
 * Renders the 'core/legacy-widget' block.
 *
 * @since 5.8.0
 *
 * @global int $wp_widget_factory.
 *
 * @param array $attributes The block attributes.
 *
 * @return string Rendered block.
 */
function render_block_core_legacy_widget( $attributes ) {
    global $wp_widget_factory;

    if ( isset( $attributes['id'] ) ) {
        $sidebar_id = wp_find_widgets_sidebar( $attributes['id'] );
        return wp_render_widget( $attributes['id'], $sidebar_id );
    }

    if ( ! isset( $attributes['idBase'] ) ) {
        return '';
    }

    $id_base       = $attributes['idBase'];
    $widget_key    = $wp_widget_factory->get_widget_key( $id_base );
    $widget_object = $wp_widget_factory->get_widget_object( $id_base );

    if ( ! $widget_key || ! $widget_object ) {
        return '';
    }

    if ( isset( $attributes['instance']['encoded'], $attributes['instance']['hash'] ) ) {
        $serialized_instance = base64_decode( $attributes['instance']['encoded'] );
        if ( ! hash_equals( wp_hash( $serialized_instance ), (string) $attributes['instance']['hash'] ) ) {
            return '';
        }
        $instance = unserialize( $serialized_instance );
    } else {
        $instance = array();
    }

    $args = array(
        'widget_id'   => $widget_object->id,
        'widget_name' => $widget_object->name,
    );

    ob_start();
    the_widget( $widget_key, $instance, $args );
    return ob_get_clean();
}

/**
 * Registers the 'core/legacy-widget' block.
 *
 * @since 5.8.0
 */
function register_block_core_legacy_widget() {
    register_block_type_from_metadata(
        __DIR__ . '/legacy-widget',
        array(
            'render_callback' => 'render_block_core_legacy_widget',
        )
    );
}

add_action( 'init', 'register_block_core_legacy_widget' );

/**
 * Intercepts any request with legacy-widget-preview in the query param and, if
 * set, renders a page containing a preview of the requested Legacy Widget
 * block.
 *
 * @since 5.8.0
 */
function handle_legacy_widget_preview_iframe() {
    if ( empty( $_GET['legacy-widget-preview'] ) ) {
        return;
    }

    if ( ! current_user_can( 'edit_theme_options' ) ) {
        return;
    }

    define( 'IFRAME_REQUEST', true );

    ?>
    <!doctype html>
    <html <?php language_attributes(); ?>>
    <head>
        <meta charset="<?php bloginfo( 'charset' ); ?>" />
        <meta name="viewport" content="width=device-width, initial-scale=1" />
        <link rel="profile" href="https://gmpg.org/xfn/11" />
        <?php wp_head(); ?>
        <style>
            /* Reset theme styles */
            html, body, #page, #content {
                padding: 0 !important;
                margin: 0 !important;
            }

            /* Hide root level text nodes */
            body {
                font-size: 0 !important;
            }

            /* Hide non-widget elements */
            body *:not(#page):not(#content):not(.widget):not(.widget *) {
                display: none !important;
                font-size: 0 !important;
                height: 0 !important;
                left: -9999px !important;
                max-height: 0 !important;
                max-width: 0 !important;
                opacity: 0 !important;
                pointer-events: none !important;
                position: absolute !important;
                top: -9999px !important;
                transform: translate(-9999px, -9999px) !important;
                visibility: hidden !important;
                z-index: -999 !important;
            }

            /* Restore widget font-size */
            .widget {
                font-size: var(--global--font-size-base);
            }
        </style>
    </head>
    <body <?php body_class(); ?>>
        <div id="page" class="site">
            <div id="content" class="site-content">
                <?php
                $registry = WP_Block_Type_Registry::get_instance();
                $block    = $registry->get_registered( 'core/legacy-widget' );
                echo $block->render( $_GET['legacy-widget-preview'] );
                ?>
            </div><!-- #content -->
        </div><!-- #page -->
        <?php wp_footer(); ?>
    </body>
    </html>
    <?php

    exit;
}

// Use admin_init instead of init to ensure get_current_screen function is already available.
// This isn't strictly required, but enables better compatibility with existing plugins.
// See: https://github.com/WordPress/gutenberg/issues/32624.
add_action( 'admin_init', 'handle_legacy_widget_preview_iframe', 20 );