JezK
Edit File: legacy-widget.php
<?php /** * Server-side rendering of the `core/legacy-widget` block. * * @package WordPress */ /** * Renders the 'core/legacy-widget' block. * * @since 5.8.0 * * @global WP_Widget_Factory $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 );