` (with a responsive imagesrcset) in the * , so the browser starts fetching it before it parses the body. * * Opt-in via `perf_preload_lcp`. Scoped to singular views for v1. */ class LcpPreload { public static function init() { if ( is_admin() ) { return; } $enabled = (bool) apply_filters( 'ablocks/perf/perf_preload_lcp', (bool) Helper::get_settings( 'perf_preload_lcp', true ) ); if ( ! $enabled ) { return; } $self = new self(); add_action( 'wp_head', [ $self, 'print_preload' ], 2 ); } public function print_preload() { if ( ! is_singular() ) { return; } $post = get_post(); if ( ! $post || false === strpos( (string) $post->post_content, 'wp:ablocks/image' ) ) { return; } $image = $this->first_image_block( parse_blocks( $post->post_content ) ); if ( ! $image ) { return; } $href = esc_url( $image['url'] ); $attrs = 'rel="preload" as="image" fetchpriority="high" href="' . $href . '"'; if ( ! empty( $image['id'] ) ) { $srcset = wp_get_attachment_image_srcset( (int) $image['id'], 'full' ); if ( $srcset ) { $sizes = wp_get_attachment_image_sizes( (int) $image['id'], 'full' ); $attrs .= ' imagesrcset="' . esc_attr( $srcset ) . '"'; if ( $sizes ) { $attrs .= ' imagesizes="' . esc_attr( $sizes ) . '"'; } } } echo "\n"; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped } /** * Depth-first search for the first aBlocks image block that carries a URL. * Returns [ 'url' => …, 'id' => … ] or null. */ private function first_image_block( $blocks ) { foreach ( $blocks as $block ) { if ( ! empty( $block['blockName'] ) && 'ablocks/image' === $block['blockName'] ) { $url = $block['attrs']['imgUrl'] ?? ''; if ( $url && 0 !== strpos( $url, 'ablocks_dc:' ) ) { return [ 'url' => $url, 'id' => $block['attrs']['imgId'] ?? 0, ]; } } if ( ! empty( $block['innerBlocks'] ) ) { $found = $this->first_image_block( $block['innerBlocks'] ); if ( $found ) { return $found; } } } return null; } }