Order Search Results by Post Type

search.php

<?php

/**
 * This is copied from Know The Code's
 * KTC-Child Theme
 * @source: https://github.com/KnowTheCode/KTC-Child-Theme/blob/master/lib/structure/search.php
 * Mostly so i can find it in the future
 */

add_filter( 'posts_orderby', __NAMESPACE__ . '\add_orderby_for_search_query', 50 );
/**
 * Add the ORDER BY for the Search Query.
 *
 * @since 1.5.0
 *
 * @param string $orderby_sql
 *
 * @return string
 */
function add_orderby_for_search_query( $orderby_sql ) {
	if ( ! is_search() ) {
		return $orderby_sql;
	}
	global $wpdb;
	$post_type_order = array(
		'lab',
//		'challenge',
//		'explained',
		'post',
		'docx',
		'glossary',
		'help-center',
		'page',
	);
	$sql_query = "CASE {$wpdb->posts}.post_type";
	foreach( $post_type_order as $order => $post_type ) {
		$sql_query .= " WHEN '{$post_type}' THEN " . ( $order + 1 );
	}
	$sql_query .= ' END';
	return $sql_query;
}