1<?php
  2/**
  3 * Sitemaps: WP_Sitemaps_Index class.
  4 *
  5 * Generates the sitemap index.
  6 *
  7 * @package WordPress
  8 * @subpackage Sitemaps
  9 * @since 5.5.0
 10 */
 11
 12/**
 13 * Class WP_Sitemaps_Index.
 14 * Builds the sitemap index page that lists the links to all of the sitemaps.
 15 *
 16 * @since 5.5.0
 17 */
 18#[AllowDynamicProperties]
 19class WP_Sitemaps_Index {
 20	/**
 21	 * The main registry of supported sitemaps.
 22	 *
 23	 * @since 5.5.0
 24	 * @var WP_Sitemaps_Registry
 25	 */
 26	protected $registry;
 27
 28	/**
 29	 * Maximum number of sitemaps to include in an index.
 30	 *
 31	 * @since 5.5.0
 32	 *
 33	 * @var int Maximum number of sitemaps.
 34	 */
 35	private $max_sitemaps = 50000;
 36
 37	/**
 38	 * WP_Sitemaps_Index constructor.
 39	 *
 40	 * @since 5.5.0
 41	 *
 42	 * @param WP_Sitemaps_Registry $registry Sitemap provider registry.
 43	 */
 44	public function __construct( WP_Sitemaps_Registry $registry ) {
 45		$this->registry = $registry;
 46	}
 47
 48	/**
 49	 * Gets a sitemap list for the index.
 50	 *
 51	 * @since 5.5.0
 52	 *
 53	 * @return array[] Array of all sitemaps.
 54	 */
 55	public function get_sitemap_list() {
 56		$sitemaps = array();
 57
 58		$providers = $this->registry->get_providers();
 59		/* @var WP_Sitemaps_Provider $provider */
 60		foreach ( $providers as $name => $provider ) {
 61			$sitemap_entries = $provider->get_sitemap_entries();
 62
 63			// Prevent issues with array_push and empty arrays on PHP < 7.3.
 64			if ( ! $sitemap_entries ) {
 65				continue;
 66			}
 67
 68			// Using array_push is more efficient than array_merge in a loop.
 69			array_push( $sitemaps, ...$sitemap_entries );
 70			if ( count( $sitemaps ) >= $this->max_sitemaps ) {
 71				break;
 72			}
 73		}
 74
 75		return array_slice( $sitemaps, 0, $this->max_sitemaps, true );
 76	}
 77
 78	/**
 79	 * Builds the URL for the sitemap index.
 80	 *
 81	 * @since 5.5.0
 82	 *
 83	 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 84	 *
 85	 * @return string The sitemap index URL.
 86	 */
 87	public function get_index_url() {
 88		global $wp_rewrite;
 89
 90		if ( ! $wp_rewrite->using_permalinks() ) {
 91			return home_url( '/?sitemap=index' );
 92		}
 93
 94		return home_url( '/wp-sitemap.xml' );
 95	}
 96}
 97