Relevanssi product category pinning

rlv_category_pinning.php

<?php

/**
 * This will lift all the product categories in the results on top of the results.
 */
add_filter( 'relevanssi_hits_filter', 'rlv_lift_category', 20 );
function rlv_lift_category( $hits ) {
	$categories  = array();
	$other_posts = array();
	foreach ( $hits[0] as $hit ) {
		if ( 'product_category' === $hit->post_type ) {
			$categories[] = $hit;
		} else {
			$other_posts[] = $hit;
		}
	}

	$hits[0] = array_merge( $categories, $other_posts );
	return $hits;
}

/**
 * This function is used to add the extra keywords to the category pages.
 */
add_filter( 'relevanssi_tax_term_additional_content', 'rlv_add_terms', 10, 2 );
function rlv_add_terms( $content, $term ) {
	if ( 'Premium Mattresses' === $term->name ) {
		$content .= 'mattress collection';
	}
	return $content;
}