Index WooCommerce Product Variations with Products in SearchWP

searchwp-customizations.php

<?php

// Add WooCommerce Product Variation data to parent Products in SearchWP.
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_product_variations';

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

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

	// Customize the data indexed for each Variation.
	$data['meta'][ $my_extra_meta_key ] = array_filter( $product_variations, function( $variation ) {
		$variation->searchwp_variation_data = [
			'title'   => get_the_title( $variation->ID ),
			'content' => $variation->post_content,
			'sku'     => get_post_meta( $variation->ID, '_sku', true ),
		];

		return $variation;
	} );

	return $data;
}, 20, 2 );

// Add our Extra Meta entry to SearchWP's UI.
add_filter( 'searchwp\source\attribute\options\special', 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_product_variations';
	$option = new \SearchWP\Option( $my_extra_meta_key, 'Product Variations' );

	// 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 "Product Variations" Option
	$keys[] = $option;

	return $keys;
}, 20, 2 );