Rewrite Custom Taxonomies Routes

rewrite_custom_taxonomies_routes.php

<?php
/*
 * Replace Taxonomy slug with Post Type slug in url
 * Version: 1.1
 */

function ss_fix_portfolio_rewrite($wp_rewrite) {
	$rules = array();
  
	// get all custom taxonomies
	$taxonomies = get_taxonomies(array('_builtin' => false), 'objects');
  
	// get all custom post types
	$post_types = get_post_types(array(
		'public' => true,
		'_builtin' => false),
	'objects');
  
	foreach ($post_types as $post_type) {
		$post_type_name = $post_type->name;
		$post_type_slug = $post_type->name;
		if ( $post_type->rewrite && $post_type->rewrite['slug'] ){
			$post_type_slug = $post_type->rewrite['slug'];
		}
		
		foreach ($taxonomies as $taxonomy) {
  
			// check if taxonomy is registered for this custom type
			if ($taxonomy->object_type[0] == $post_type_name) {
  
				// get all categories (terms)
				$categories = get_categories(array(
					'type' => $post_type_name,
					'taxonomy' => $taxonomy->name,
					'hide_empty' => 0
				));
  
				// make rules
				foreach ($categories as $category) {
					$rules[$post_type_slug . '/' . $category->slug . '/?$'] = 
					'index.php?' . $category->taxonomy . '=' . $category->slug;
				}
			}
		}
	}
  
	// merge with global rules
	$wp_rewrite->rules = $rules + $wp_rewrite->rules;
}
add_filter('generate_rewrite_rules', 'ss_fix_portfolio_rewrite');