` that has NO non-empty alt, resolve its attachment and * inject that attachment's `_wp_attachment_image_alt`. The **attachment meta is * the single source of truth** — set it once on the media item (durable) and it * flows to every place the image renders. * * Safety: * - Only ever FILLS a blank alt; never overwrites a non-empty one. * - Only acts when an attachment is resolvable AND its meta alt is non-empty, * so decorative theme assets (dash.svg, quote marks, SVG icons — not in the * media library) are left untouched with their empty alt, which is correct. * - Front-end only; leaves the admin/editor markup alone. */ if ( ! defined( 'ABSPATH' ) ) { exit; } /** * Resolve an attachment ID from a rendered image src, tolerating resized * (`-1024x768`) and `.jpg.webp` derivative filenames. Cached per request. * * @param string $url * @return int Attachment ID or 0. */ function bw_img_alt_resolve_from_src( $url ) { static $cache = array(); if ( '' === $url ) { return 0; } if ( isset( $cache[ $url ] ) ) { return $cache[ $url ]; } // Strip a size suffix that sits before the (possibly double) extension: // large-x.jpg-768x1150.webp -> large-x.jpg.webp // i8300-768x1152.jpg -> i8300.jpg $orig = preg_replace( '/-\d+x\d+(\.[a-z0-9]+)(\.webp)?$/i', '$1$2', $url ); $id = attachment_url_to_postid( $orig ); if ( ! $id ) { // Fallback: match the file basename against _wp_attached_file. global $wpdb; $base = basename( wp_parse_url( $orig, PHP_URL_PATH ) ); if ( '' !== $base ) { $id = (int) $wpdb->get_var( $wpdb->prepare( "SELECT post_id FROM {$wpdb->postmeta} WHERE meta_key = '_wp_attached_file' AND meta_value LIKE %s LIMIT 1", '%' . $wpdb->esc_like( $base ) . '%' ) ); } } $cache[ $url ] = $id ? (int) $id : 0; return $cache[ $url ]; } /** * The non-empty attachment alt for an id, cached per request. * * @param int $id * @return string */ function bw_img_alt_for( $id ) { static $cache = array(); $id = (int) $id; if ( ! $id ) { return ''; } if ( isset( $cache[ $id ] ) ) { return $cache[ $id ]; } return $cache[ $id ] = trim( (string) get_post_meta( $id, '_wp_attachment_image_alt', true ) ); } /** * Fill blank alts in a rendered block from the images' attachment meta. * * @param string $html Rendered block HTML. * @param array $block Parsed block (name + attrs). * @return string */ function bw_img_alt_render( $html, $block ) { if ( is_admin() ) { return $html; } if ( false === stripos( $html, ' already has a non-empty alt. if ( ! preg_match( '/]*\balt\s*=\s*"[^"]+")[^>]*>/i', $html ) ) { return $html; } // Single-image custom card: trust the block's own imageId. $block_img_id = 0; if ( isset( $block['blockName'], $block['attrs']['imageId'] ) && 'bw/interlinking' === $block['blockName'] ) { $block_img_id = (int) $block['attrs']['imageId']; } return preg_replace_callback( '/]*>/i', function ( $m ) use ( $block_img_id ) { $tag = $m[0]; // Already has a non-empty alt → leave it. if ( preg_match( '/\balt\s*=\s*"[^"]+"/i', $tag ) ) { return $tag; } $id = $block_img_id; if ( ! $id && preg_match( '/wp-image-(\d+)/i', $tag, $c ) ) { $id = (int) $c[1]; } if ( ! $id && preg_match( '/\bsrc\s*=\s*"([^"]+)"/i', $tag, $s ) ) { $id = bw_img_alt_resolve_from_src( $s[1] ); } if ( ! $id ) { return $tag; // unresolvable (e.g. decorative theme asset) — leave blank } $alt = bw_img_alt_for( $id ); if ( '' === $alt ) { return $tag; // attachment has no alt either — nothing to inject } $attr = 'alt="' . esc_attr( $alt ) . '"'; if ( preg_match( '/\balt\s*=\s*"[^"]*"/i', $tag ) ) { // Replace an existing empty alt="". return preg_replace( '/\balt\s*=\s*"[^"]*"/i', $attr, $tag, 1 ); } // No alt attribute at all — add one. return preg_replace( '/