Sort by custom field in WordPress

sort-by-custom-field.php

<?php
// Taken and modified from https://www.advancedcustomfields.com/resources/orde-posts-by-custom-fields/
// Put here for posterity's sake as a bookmark of sorts
// Allows sorting by custom field value instead of default. 
// This will allow client to be able to set the order of these goals/landing pages as they add more.
// Can be added to functions.php, or to custom template that gets called before your custom loop.

function my_pre_get_posts( $query ) {

	// do not modify queries in the admin
	if( is_admin() ) {

		return $query;

	}


	// only modify queries for 'goals' post type (edit for your own post type)
	if( isset($query->query_vars['post_type']) && $query->query_vars['post_type'] == 'goals' ) {

		$query->set('orderby', 'meta_value');
		$query->set('meta_key', 'goal_order_in_list'); // Set the meta_key to match the ACF "Field Name" (in this case goal_order_in_list)
		$query->set('order', 'ASC');

	}


	// return
	return $query;

}

add_action('pre_get_posts', 'my_pre_get_posts');

?>