[SmartCrawl Pro] Multilingual sitemap (WPML integration) [Alt version]

smartcrawl-multilingual-sitemap-alt.php

<?php
/**
 * Plugin Name: [SmartCrawl Pro] Multilingual sitemap (WPML integration) [Alt version]
 * Description: Improves the SmartCrawl sitemaps with multilingual-ready capabilities when the WPML plugin is present
 * Author: Anderson Salas @ WPMUDEV
 * Task: SLS-5524
 * Author URI: https://premium.wpmudev.org
 * License: GPLv2 or later
 */

// This snippet is a simplified version of:
// https://gist.github.com/wpmudev-sls/d14cbe94eef14de670b7c9e0a77631b2

add_action( 'plugins_loaded', function() {
	if ( ! class_exists( 'Smartcrawl_Sitemap_Post_Fetcher' ) ) {
		return; // SmartCrawl is not installed/enabled.
	}

	if ( ! defined( 'ICL_SITEPRESS_VERSION' ) ) {
		return; // WPML is not installed/enabled.
	}

	add_filter( 'wds_partial_sitemap_items', function( $items, $type, $page ) {
		global $wpdb;

		// ---------------------------------------------------------------------------- //
		// Modify this array with the Custom Post Types to be translated in the Sitemap 
		// or leave it as a blank array to use all the public available types    
		// ---------------------------------------------------------------------------- //
		$allowed_types = array();
		// ---------------------------------------------------------------------------- //

		if ( empty( $allowed_types ) ) {
			$allowed_types = get_post_types(
				array(
					'show_ui'  => true, 
					'public'   => true,
                    '_builtin' => false,
				)
			);
			$allowed_types = array_keys( $allowed_types );
		}

		if ( empty( $allowed_types ) || ( ! empty( $allowed_types ) && ! in_array( $type, $allowed_types ) ) ) {
			return $items; // Type not allowed.
		}

		if ( empty( $items ) ) {
			return $items; // Nothing to handle.
		}
		
		$grouped_items = array();

		foreach( $items as $item ) {
			if ( ! isset( $grouped_items[ $item->get_location() ] ) ) {
				$grouped_items[ $item->get_location() ] = array(
					'id'       => url_to_postid( $item->get_location() ),
					'variants' => array(),
					'item'     => $item,
				);
			} else {
				$grouped_items[ $item->get_location() ]['variants'][ $item->get_last_modified() ] = $item;
			}
		}

		if ( empty( $items ) ) {
			return $items;
		}

		$p      = $wpdb->prefix;
		$ids_in = implode( ',', array_column( $grouped_items, 'id' ) );
		$query  = "SELECT 
			( 
				SELECT 
					element_id 
				FROM 
					{$p}icl_translations 
				WHERE 
					trid = t.trid
					AND element_type = 'post_$type' 
					AND source_language_code IS NULL LIMIT 1 
			) parent_id,
			p.id post_id,
			p.guid post_url,
			t.language_code post_lang,
			UNIX_TIMESTAMP( p.post_modified_gmt ) post_date
		FROM 
			{$p}icl_translations t
			LEFT JOIN {$p}posts p ON p.ID = t.element_id
		WHERE 
			trid IN ( 
				SELECT 
					trid 
				FROM 
					{$p}icl_translations
				WHERE 
					element_id IN ($ids_in) 
					AND element_type  = 'post_$type'
					AND p.post_status = 'publish'
			) 
			AND t.element_id NOT IN ($ids_in)";

		$posts = $wpdb->get_results( $query, ARRAY_A ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared	
		
		if ( empty( $posts ) ) {
			return $items; // Empty result set (probably due to a DB query error).
		}
		
		$result = array();

		foreach( $grouped_items as &$item ) {
            $result[] = $item['item'];
			foreach( $posts as $post ) {
				if( $item['id'] === (int) $post['parent_id'] ) {
                    $variant = clone $item['item'];
                    $variant->set_location( apply_filters( 'wpml_permalink', $post['post_url'], $post['post_lang'] ) );
                    $result[] = $variant;
				}
			}
		}

		return $result;
	}, 10, 3 );
});