Woocommerce sortable columns not working - woocommerce

Question

I've added a couple of custom field columns to our Woocommerce orders list in the admin of WordPress using the methods below, but the sort is not working....
add_filter( 'manage_edit-shop_order_columns', 'my_wc_columns' );
function my_wc_columns($columns){
$new_columns = (is_array($columns)) ? $columns : array();
unset( $new_columns['order_actions'] );
$new_columns['program_id'] = 'Program';
$new_columns['constituent_id'] = 'Constituent ID';
$new_columns['order_actions'] = $columns['order_actions'];
return $new_columns;
}
add_action( 'manage_shop_order_posts_custom_column', 'my_wc_column_values', 2 );
function my_wc_column_values($column){
global $post;
if ( $column == 'program_id' ) {
$program = get_post_meta( $post->ID, '_program_id', true );
$program_title = get_the_title($program);
$column_val = (isset($program) && $program>0 ? $program_title : 'All');
echo '<span>' . my_programs_get_name( $column_val ) . ' (' . $program . ')</span>';
}
if ( $column == 'constituent_id' ) {
$consid = get_post_meta( $post->ID, 'constituent_id', true );
$column_val = (isset($consid) && $consid != "") ? $consid : "";
echo '<span>' . $column_val . '</span>';
}
}
// Make column sortable
add_filter( "manage_edit-shop_order_sortable_columns", 'my_wc_column_sort' );
function my_wc_column_sort( $columns ) {
$custom = array(
'program_id' => '_program_id',
'constituent_id' => 'constituent_id',
);
return wp_parse_args( $custom, $columns );
}
I expected to have an issue perhaps with the program name, since it is an id that needs to be translated via a custom function to a name, but neither column is sorting properly. The records change order after clicking their column titles, but I cannot tell how the sort is being done. The program is not sorting on name or ID and both are seem random but consistent. Keep in mind both fields are custom fields that may or may not have a value defined. How can I make this sortable?

Answer 1

Here's a good tutorial on custom sortable columns. After you register the column, you need to handle the actual sorting. Sadly, that part doesn't happen automagically. Untested, but adapted from the above tutorial:
add_action( 'pre_get_posts', 'manage_wp_posts_be_qe_pre_get_posts', 1 );
function manage_wp_posts_be_qe_pre_get_posts( $query ) {
/**
* We only want our code to run in the main WP query
* AND if an orderby query variable is designated.
*/
if ( $query->is_main_query() && ( $orderby = $query->get( 'orderby' ) ) ) {
switch( $orderby ) {
// If we're ordering by 'program_id'
case 'program_id':
// set our query's meta_key, which is used for custom fields
$query->set( 'meta_key', '_program_id' );
/**
* Tell the query to order by our custom field/meta_key's
* value
*
* If your meta value are numbers, change 'meta_value'
* to 'meta_value_num'.
*/
$query->set( 'orderby', 'meta_value' );
break;
}
}
}