Disables the Genre taxonomy archive in the Novelist plugin.

novelist-no-genre-archive.php

<?php
/**
 * Plugin Name: Novelist - No Genre Archive
 * Plugin URI: https://www.nosegraze.com
 * Description: Removes the genre archive pages and turns the genre list into plain text.
 * Version: 1.0
 * Author: Nose Graze
 * Author URI: https://www.nosegraze.com
 * License: GPL2
 *
 * @package   novelist-no-genre-archive
 * @copyright Copyright (c) 2016, Nose Graze Ltd.
 * @license   GPL2+
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

/**
 * Disable "show in nav menus" and "show tag cloud" features.
 *
 * @param array $args
 *
 * @since 1.0
 * @return array
 */
function novelist_disable_genre_taxonomy_features( $args ) {
	$new_args = array(
		'public'            => false,
		'show_in_nav_menus' => false,
		'show_tagcloud'     => false,
	);

	return wp_parse_args( $new_args, $args );
}

add_filter( 'novelist/taxonomy/genre-args', 'novelist_disable_genre_taxonomy_features' );

/**
 * Modify Genre Query
 *
 * If a `novelist-genre` query is being performed then set that to a 404.
 *
 * @param WP_Query $query
 *
 * @since 1.0
 * @return void
 */
function novelist_modify_genre_query( $query ) {
	if ( is_admin() ) {
		return;
	}

	if ( is_tax( 'novelist-genre' ) ) {
		$query->set_404();
	}
}

add_action( 'pre_get_posts', 'novelist_modify_genre_query' );

/**
 * Remove Genre Archive Links
 *
 * Modifies Novelist_Book::get_genres()
 *
 * @param string $genre_list Genre list with links to archives.
 * @param int    $book_id    ID of the book we're querying.
 *
 * @since 1.0
 * @return bool|string False on failure, comma-separated list on success.
 */
function novelist_remove_genre_archive_links( $genre_list, $book_id ) {
	$genres = wp_get_post_terms( $book_id, 'novelist-genre', array( 'fields' => 'names' ) );

	if ( ! is_array( $genres ) ) {
		return false;
	}

	return implode( ', ', $genres );
}

add_filter( 'novelist/book/get/genre', 'novelist_remove_genre_archive_links', 10, 2 );