Add WooCommerce Product (and Variation) SKUs to SearchWP

searchwp-customizations.php

<?php

// Add WooCommerce Product (and Variation) SKUs to SearchWP.
// @link https://searchwp.com/documentation/knowledge-base/search-woocommerce-skus-and-variation-skus/
add_filter( 'searchwp\entry\data', function( $data, \SearchWP\Entry $entry ) {
	// If this is not a Product, there's nothing to do.
	if ( 'product' !== get_post_type( $entry->get_id() ) ) {
		return $data;
	}

	$my_extra_meta_key = 'searchwp_skus';

	// Retrieve this Product SKU.
	$data['meta'][ $my_extra_meta_key ] = [
		get_post_meta( $entry->get_id(), '_sku', true )
	];

	// Retrieve all Variations.
	$product_variations = get_posts( [
		'post_type'       => 'product_variation',
		'posts_per_page'  => -1,
		'fields'          => 'ids',
		'post_parent'     => $entry->get_id(),
	] );

	if ( empty( $product_variations ) ) {
		return $data;
	}

	// Append all Product Variation SKUs.
	foreach ( $product_variations as $product_variation ) {
		$sku = get_post_meta( $product_variation, '_sku', true );
		$data['meta'][ $my_extra_meta_key ][] = $sku;
	}

	return $data;
}, 20, 2 );


// Add our Extra Meta entry to SearchWP's UI.
// @link https://searchwp.com/documentation/knowledge-base/search-woocommerce-skus-and-variation-skus/
add_filter( 'searchwp\source\attribute\options', function( $keys, $args ) {
	if ( $args['attribute'] !== 'meta' ) {
		return $keys;
	}

	// This key is the same as the one used in the searchwp\entry\data hook above, they must be the same.
	$my_extra_meta_key = 'searchwp_skus';
	$option = new \SearchWP\Option( $my_extra_meta_key, 'SearchWP WooCommerce SKUs' );
	
	// If there's already a match, remove it because we want ours there.
	$keys = array_filter( $keys, function( $option ) use ( $my_extra_meta_key ) {
		return $my_extra_meta_key !== $option->get_value();
	} );
	
	// Add "SearchWP WooCommerce SKUs" Option
	$keys[] = $option;

	return $keys;
}, 20, 2 );