Sync attachment titles and alt text across WordPress multisite sites

gistfile1.txt

<?php
/**
 * Plugin Name: Sync Attachment Meta
 * Description: Sync attachment titles and alt text across multisite sites. Choose a source site to pull titles and alt text from, and have matching attachments updated on all other sites.
 * Version: 1.0.0
 */

// Confirm that WP-CLI is available.
if ( defined( 'WP_CLI' ) && WP_CLI ) {

	/**
	 * Sync attachment titles and alt text across multisite sites.
	 */
	class Sync_Attachment_Meta_Command {

		/**
		 * Sync titles and alt text based on post_title or filename match.
		 *
		 * <source_site_id> The ID of the source site to pull titles/alt text from.
		 *
		 * Example Command: wp sync-attachment-meta 1
		 */
		public function __invoke( $args ) {
			list( $source_site_id ) = $args;

			if ( ! is_multisite() ) {
				WP_CLI::error( 'This script only works on multisite installs.' );
			}

			$sites = get_sites();

			// Switch to the source site and get attachments.
			switch_to_blog( $source_site_id );
			WP_CLI::log( "Switched to source site: {$source_site_id}" );

			// Get all attachments on the source site.
			// Note: This will only get attachments that are in the media library.
			$attachments = get_posts(
				array(
					'post_type'      => 'attachment',
					'post_status'    => 'inherit',
					'posts_per_page' => -1,
				)
			);

			// Display count of attachments found.
			WP_CLI::log( 'Found ' . count( $attachments ) . ' attachments on source site.' );

			// Collect source site attachment data indexed by both title and filename.
			$attachment_data = array();

			foreach ( $attachments as $attachment ) {
				$alt_text  = get_post_meta( $attachment->ID, '_wp_attachment_image_alt', true );
				$file_path = get_post_meta( $attachment->ID, '_wp_attached_file', true );
				$file_name = basename( $file_path );

				// Add both title and filename as keys for quick lookup.
				$attachment_data[ $attachment->post_title ] = array(
					'title'   => $attachment->post_title,
					'caption' => $attachment->post_excerpt,
					'alt'     => $alt_text,
					'file'    => $file_name,
				);

				$attachment_data[ $file_name ] = array(
					'title'   => $attachment->post_title,
					'caption' => $attachment->post_excerpt,
					'alt'     => $alt_text,
					'file'    => $file_name,
				);
			}

			restore_current_blog();

			// Loop through all sites and update matching attachments.
			foreach ( $sites as $site ) {
				$site_id = (int) $site->blog_id;

				// Skip the source site.
				if ( $site_id === (int) $source_site_id ) {
					continue;
				}

				// Display site ID being processed.
				WP_CLI::log( "Processing site ID: {$site_id}" );
				switch_to_blog( $site_id );

				$site_attachments = get_posts(
					array(
						'post_type'      => 'attachment',
						'post_status'    => 'inherit',
						'posts_per_page' => -1,
					)
				);

				$updated_count = 0;

				foreach ( $site_attachments as $site_attachment ) {
					$site_file_path = get_post_meta( $site_attachment->ID, '_wp_attached_file', true );
					$site_file_name = basename( $site_file_path );
					$site_title     = $site_attachment->post_title;

					$matched_data = null;

					// Check if there's a match by post_title or file_name.
					if ( isset( $attachment_data[ $site_title ] ) ) {
						$matched_data = $attachment_data[ $site_title ];
					} elseif ( isset( $attachment_data[ $site_file_name ] ) ) {
						$matched_data = $attachment_data[ $site_file_name ];
					}

					if ( $matched_data ) {
						// Update post title and caption.
						wp_update_post(
							array(
								'ID'           => $site_attachment->ID,
								'post_title'   => $matched_data['title'],
								'post_excerpt' => $matched_data['caption'],
							)
						);

						// Check if alt text already exists on this attachment.
						$existing_alt_text = get_post_meta( $site_attachment->ID, '_wp_attachment_image_alt', true );

						if ( empty( $existing_alt_text ) ) {
							// If there is no alt text, add it.
							update_post_meta( $site_attachment->ID, '_wp_attachment_image_alt', $matched_data['alt'] );

							WP_CLI::log( "Updated attachment ID {$site_attachment->ID} on site {$site_id} (matched by title or filename: {$matched_data['file']}, alt text added)" );
						} else {
							// Alt text already exists, skip updating
							WP_CLI::log( "Skipped alt text for attachment ID {$site_attachment->ID} on site {$site_id} (alt text already present)" );
						}

						++$updated_count;
					}
				}

				WP_CLI::log( "Site {$site_id} complete. Updated {$updated_count} attachments." );

				restore_current_blog();
			}

			WP_CLI::success( 'Attachment meta sync complete!' );
		}
	}

	WP_CLI::add_command( 'sync-attachment-meta', 'Sync_Attachment_Meta_Command' );
}