Create hierarchical permalink SEO silos for WooCommerce shop/products, product categories, and single product urls.

woocommerce-permalink-silos.php

<?php
/**
 * Mai WooCommerce Permalink Silos.
 *
 * @version   1.2.0
 *
 * @package   BizBudding\MaiWooCommercePermalinkSilos
 * @link      https://bizbudding.com
 * @author    BizBudding
 * @copyright Copyright © 2023 BizBudding
 * @license   GPL-2.0-or-later
 */

/**
 * Instantiate the class.
 *
 * @link https://gist.github.com/JiveDig/4ffab84ebd2b0aea6aa5af94df7ef281
 *
 * @return void
 */
new Mai_WooCommerce_Permalink_Silos;

/**
 * Create silos for WooCommerce shop/products, product categories, and single product urls.
 *
 * Shop:                    `/{shop base}/`
 * Product categories/tags: `/{shop base}/{product category or tag slug}/`
 * Single Product:          `/{shop base}/{product category or tag slug}/{product slug}`
 *
 * @link https://gist.github.com/JiveDig/4ffab84ebd2b0aea6aa5af94df7ef281
 *
 * @return void
 */
class Mai_WooCommerce_Permalink_Silos {
	protected $taxonomies = [ 'product_cat', 'product_tag' ];

	/**
	 * Constructs the class.
	 *
	 * @since 1.0.0
	 *
	 * @return void
	 */
	function __construct() {
		add_action( 'template_redirect',             [ $this, 'maybe_redirect' ] );
		add_action( 'current_screen',                [ $this, 'remove_settings' ], 99 );
		add_filter( 'option_woocommerce_permalinks', [ $this, 'get_permalinks' ], 99 );
		add_filter( 'request',                       [ $this, 'base_listener' ], 99 );
		add_filter( 'term_link',                     [ $this, 'base_link' ], 99, 3 );
	}

	/**
	 * Redirect orignal term archives to the new urls.
	 * Sometimes the original urls show as is_tax(),
	 * while other times it 404's.
	 *
	 * @since 1.0.0
	 *
	 * @return void
	 */
	function maybe_redirect() {
		if ( ! $this->should_run() ) {
			return;
		}

		$is_tax = is_tax( $this->taxonomies );
		$is_404 = is_404();

		if ( ! ( $is_tax || $is_404 ) ) {
			return;
		}

		global $wp;

		$term  = false;
		$array = explode( '/', $wp->request );
		$first = reset( $array );

		// If term archive.
		if ( $is_tax ) {
			if ( $this->get_shop_base() === $first ) {
				return;
			}

			$term = get_queried_object();
		}
		// 404.
		else {
			if ( count( $array ) <= 1 ) {
				return;
			}

			if ( ! in_array( $first, [ 'product-category', 'product-tag' ] ) ) {
				return;
			}

			$map = [
				'product-category' => 'product_cat',
				'product-tag'      => 'product_tag',
			];

			$term = get_term_by( 'slug', $array[1], $map[ $first ] );
		}

		if ( ! $term || is_wp_error( $term ) ) {
			return;
		}

		if ( 'WP_Term' !== get_class( $term ) ) {
			return;
		}

		wp_safe_redirect( get_term_link( $term, $term->taxonomy ), 301, 'Mai WooCommerce Permalink Silos' );
		exit();
	}

	/**
	 * Remove permalink settings from WooCommerce.
	 * From `WC_Admin` class.
	 *
	 * @since 1.0.0
	 *
	 * @return void
	 */
	function remove_settings() {
		if ( ! $this->should_run() ) {
			return;
		}

		global $wp_settings_fields, $wp_settings_sections;

		unset( $wp_settings_fields['permalink']['optional']['woocommerce_product_category_slug'] );
		unset( $wp_settings_fields['permalink']['optional']['woocommerce_product_tag_slug'] );
		unset( $wp_settings_sections['permalink']['woocommerce-permalink'] );
	}

	/**
	 * Gets silo permalink structure.
	 *
	 * @since 1.0.0
	 *
	 * @param array $option
	 *
	 * @return array
	 */
	function get_permalinks( $option ) {
		static $cache = null;

		if ( ! is_null( $cache ) ) {
			return $cache;
		}

		$base                             = $this->get_shop_base();
		$option['product_base']           = untrailingslashit( $base ? "/{$base}/%product_cat%" : '/%product_cat%' );
		$option['category_base']          = untrailingslashit( $this->get_taxonomy_base() );
		$option['tag_base']               = untrailingslashit( $this->get_taxonomy_base() );
		$option['use_verbose_page_rules'] = true;
		$cache                            = $option;

		return $cache;
	}

	/**
	 * Gets shop base.
	 *
	 * @since 1.0.0
	 *
	 * @return string
	 */
	function get_shop_base() {
		static $cache = null;

		if ( ! is_null( $cache ) ) {
			return $cache;
		}

		$shop_id = wc_get_page_id( 'shop' );
		$cache   = $shop_id ? get_post_field( 'post_name', $shop_id ) : '';

		return $cache;
	}

	/**
	 * Gets taxonomy slug.
	 *
	 * @since 1.0.0
	 *
	 * @return string
	 */
	function get_taxonomy_base() {
		static $cache = null;

		if ( ! is_null( $cache ) ) {
			return $cache;
		}

		$base  = $this->get_shop_base();
		$cache = $base ? sprintf( '/%s/.', $base ) : '/./';

		return $cache;
	}

	/**
	 * Remove product_cat category base from category archives.
	 *
	 * @since 1.0.0
	 *
	 * @param array $request The request args.
	 *
	 * @return array
	 */
	function base_listener( $request ) {
		if ( ! $this->should_run() ) {
			return $request;
		}

		$slug  = false;
		$array = array_merge( [ 'attachment', 'product' ], $this->taxonomies );

		// Find and set slug from page request.
		foreach ( $array as $index => $var ) {
			if ( ! isset( $request[ $var ] ) || empty( $request[ $var ] ) || 'page' === $request[ $var ] ) {
				continue;
			}

			$slug = $request[ $var ];
			break;
		}

		if ( ! $slug ) {
			return $request;
		}

		// Get final slug, incase of hierarchy like `/parent-cat/child-cat/`.
		$array = explode( '/', $slug );
		$slug  = end( $array );

		global $wpdb, $wp;
		$taxos   = "'" . implode( "','", $this->taxonomies ) . "'";
		$term_id = $wpdb->get_var( $wpdb->prepare( "SELECT t.term_id FROM $wpdb->terms t LEFT JOIN $wpdb->term_taxonomy tt ON tt.term_id = t.term_id WHERE tt.taxonomy IN ($taxos) AND t.slug = %s", [ $slug ] ) );

		if ( ! $term_id ) {
			return $request;
		}

		// Structure to string.
		$structure = explode( '/', $wp->request );

		// Get paged and remove paging from structure.
		$paged = false;

		foreach ( [ 'paged', 'page' ] as $page ) {
			if ( ! isset( $request[ $page ] ) || empty( $request[ $page ] ) ) {
				continue;
			}

			$paged     = $request[ $page ];
			$structure = array_diff( $structure, [ 'page', (string) $request[ $page ] ] );
		}

		// Get first and last item.
		$first = reset( $structure );
		$last  = end( $structure );

		// Bail if the last structure item isn't the main value.
		if ( $last !== $slug ) {
			return $request;
		}

		// Bail if the first item is not the shop base.
		if ( $this->get_shop_base() !== $first ) {
			return $request;
		}

		// Get term object.
		$term = get_term( $term_id );

		// Bail if no term.
		if ( ! $term || is_wp_error( $term ) ) {
			return $request;
		}

		// Build new request.
		$old      = $request;
		$request  = [ $term->taxonomy => $slug ];
		$orderby  = ! empty( $old['orderby'] ) ? $old['orderby'] : false;
		$order    = ! empty( $old['order'] ) ? $old['order'] : false;

		if ( $paged ) {
			$request['paged'] = $paged;
		}

		if ( $orderby ) {
			$request['orderby'] = $orderby;
		}

		if ( $order ) {
			$request['order'] = $order;
		}

		return $request;
	}

	/**
	 * Remove the product category base from term links.
	 *
	 * @since 1.0.0
	 *
	 * @param string  $url      The term link url.
	 * @param WP_Term $term     The term object.
	 * @param string  $taxonomy The taxonomy name.
	 *
	 * @return string
	 */
	function base_link( $url, $term, $taxonomy ) {
		if ( ! $this->should_run() ) {
			return $url;
		}

		if ( ! in_array( $taxonomy, $this->taxonomies ) ) {
			return $url;
		}

		$url = str_replace( '/./', '/', $url );

		return $url;
	}

	/**
	 * Checks if the callback should run.
	 *
	 * @since 1.1.0
	 *
	 * @return boolean
	 */
	function should_run() {
		static $cache = null;

		if ( ! is_null( $cache ) ) {
			return $cache;
		}

		$cache = class_exists( 'WooCommerce' );

		return $cache;
	}
}