WordPress: Custom taxonomy columns with sorting support

wordpress-custom-tax-columns.php

<?php
/**
 * This example uses 'main-category' as a custom taxonomy and values
 * from Carbon Fields for sorting https://carbonfields.net
 */

// Add custom column title
add_filter( 'manage_edit-main-category_columns', function( $columns ) {
	$column_position = 2;
	$before = array_slice( $columns, 0, $column_position, true );
	$after = array_slice( $columns, $column_position, count( $columns ), true );
	$custom_column = [
		'is_public' => __( 'Public', 'your-textdomain' )
	];
	$columns = array_merge( $before, $custom_column, $after );
	return $columns;
}, 10, 3 );

// Render custom column content
add_filter( 'manage_main-category_custom_column', function( $content, $column_name, $term_id ) {
	if ( 'is_public' === $column_name ) {
		$content = carbon_get_term_meta( $term_id, 'crb_is_public' ) ? "\u{2705}" : "\u{1F6D1}"; // ✅ 🛑
	}
	return $content;
}, 10, 3 );

// Make custom column sortable
add_filter( 'manage_edit-main-category_sortable_columns', function( $sortable ) {
	$sortable[ 'is_public' ] = 'is_public';
	return $sortable;
}, 10, 3 );

// Add custom sortable content to taxonomy query
add_filter( 'terms_clauses', function( $pieces, $taxonomies, $args ) {

	global $pagenow, $wpdb;

	$custom_sort_term = 'is_public';
	$custom_taxonomy = 'main-category';

	$orderby = ( isset( $_GET[ 'orderby' ] ) ) ? trim( sanitize_text_field( $_GET[ 'orderby' ] ) ) : '';
	if ( empty( $orderby ) ) { return $pieces; }

	$taxonomy = $taxonomies[ 0 ];

	if ( ! is_admin() || 'edit-tags.php' !== $pagenow || ! in_array( $taxonomy, [ $custom_taxonomy ] ) ) {
		return $pieces;
	}

	if ( $custom_sort_term ===  $orderby ) {
		$pieces[ 'join' ] .= ' INNER JOIN ' . $wpdb->termmeta . ' AS tm ON t.term_id = tm.term_id ';
		$pieces[ 'orderby' ]  = ' ORDER BY tm.meta_value ';
		$pieces[ 'where' ] .= ' AND tm.meta_key = "_crb_is_public"';
	}
	return $pieces;

}, 10, 3 );

Thank you for this.

Excellent, couldn't find the proper way to solve this anywhere! I removed the where clause and used a left join to return terms without any value for my $custom_sort_term.

if ($this->field === $orderby) {
    $pieces['join'] .= ' LEFT JOIN ' . $wpdb->termmeta . ' AS tm ON t.term_id = tm.term_id ';
    $pieces['orderby'] = ' ORDER BY tm.meta_value ';
}