--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/sitemaps/providers/class-wp-sitemaps-taxonomies.php	Tue Dec 15 13:49:49 2020 +0100
@@ -0,0 +1,195 @@
+<?php
+/**
+ * Sitemaps: WP_Sitemaps_Taxonomies class
+ *
+ * Builds the sitemaps for the 'taxonomy' object type.
+ *
+ * @package WordPress
+ * @subpackage Sitemaps
+ * @since 5.5.0
+ */
+
+/**
+ * Taxonomies XML sitemap provider.
+ *
+ * @since 5.5.0
+ */
+class WP_Sitemaps_Taxonomies extends WP_Sitemaps_Provider {
+	/**
+	 * WP_Sitemaps_Taxonomies constructor.
+	 *
+	 * @since 5.5.0
+	 */
+	public function __construct() {
+		$this->name        = 'taxonomies';
+		$this->object_type = 'term';
+	}
+
+	/**
+	 * Returns all public, registered taxonomies.
+	 *
+	 * @since 5.5.0
+	 *
+	 * @return WP_Taxonomy[] Array of registered taxonomy objects keyed by their name.
+	 */
+	public function get_object_subtypes() {
+		$taxonomies = get_taxonomies( array( 'public' => true ), 'objects' );
+
+		$taxonomies = array_filter( $taxonomies, 'is_taxonomy_viewable' );
+
+		/**
+		 * Filter the list of taxonomy object subtypes available within the sitemap.
+		 *
+		 * @since 5.5.0
+		 *
+		 * @param WP_Taxonomy[] $taxonomies Array of registered taxonomy objects keyed by their name.
+		 */
+		return apply_filters( 'wp_sitemaps_taxonomies', $taxonomies );
+	}
+
+	/**
+	 * Gets a URL list for a taxonomy sitemap.
+	 *
+	 * @since 5.5.0
+	 *
+	 * @param int    $page_num Page of results.
+	 * @param string $taxonomy Optional. Taxonomy name. Default empty.
+	 * @return array Array of URLs for a sitemap.
+	 */
+	public function get_url_list( $page_num, $taxonomy = '' ) {
+		$supported_types = $this->get_object_subtypes();
+
+		// Bail early if the queried taxonomy is not supported.
+		if ( ! isset( $supported_types[ $taxonomy ] ) ) {
+			return array();
+		}
+
+		/**
+		 * Filters the taxonomies URL list before it is generated.
+		 *
+		 * Passing a non-null value will effectively short-circuit the generation,
+		 * returning that value instead.
+		 *
+		 * @since 5.5.0
+		 *
+		 * @param array  $url_list The URL list. Default null.
+		 * @param string $taxonomy Taxonomy name.
+		 * @param int    $page_num Page of results.
+		 */
+		$url_list = apply_filters(
+			'wp_sitemaps_taxonomies_pre_url_list',
+			null,
+			$taxonomy,
+			$page_num
+		);
+
+		if ( null !== $url_list ) {
+			return $url_list;
+		}
+
+		$url_list = array();
+
+		// Offset by how many terms should be included in previous pages.
+		$offset = ( $page_num - 1 ) * wp_sitemaps_get_max_urls( $this->object_type );
+
+		$args           = $this->get_taxonomies_query_args( $taxonomy );
+		$args['offset'] = $offset;
+
+		$taxonomy_terms = new WP_Term_Query( $args );
+
+		if ( ! empty( $taxonomy_terms->terms ) ) {
+			foreach ( $taxonomy_terms->terms as $term ) {
+				$sitemap_entry = array(
+					'loc' => get_term_link( $term ),
+				);
+
+				/**
+				 * Filters the sitemap entry for an individual term.
+				 *
+				 * @since 5.5.0
+				 *
+				 * @param array   $sitemap_entry Sitemap entry for the term.
+				 * @param WP_Term $term          Term object.
+				 * @param string  $taxonomy      Taxonomy name.
+				 */
+				$sitemap_entry = apply_filters( 'wp_sitemaps_taxonomies_entry', $sitemap_entry, $term, $taxonomy );
+				$url_list[]    = $sitemap_entry;
+			}
+		}
+
+		return $url_list;
+	}
+
+	/**
+	 * Gets the max number of pages available for the object type.
+	 *
+	 * @since 5.5.0
+	 *
+	 * @param string $taxonomy Taxonomy name.
+	 * @return int Total number of pages.
+	 */
+	public function get_max_num_pages( $taxonomy = '' ) {
+		if ( empty( $taxonomy ) ) {
+			return 0;
+		}
+
+		/**
+		 * Filters the max number of pages before it is generated.
+		 *
+		 * Passing a non-null value will short-circuit the generation,
+		 * returning that value instead.
+		 *
+		 * @since 5.5.0
+		 *
+		 * @param int    $max_num_pages The maximum number of pages. Default null.
+		 * @param string $taxonomy      Taxonomy name.
+		 */
+		$max_num_pages = apply_filters( 'wp_sitemaps_taxonomies_pre_max_num_pages', null, $taxonomy );
+
+		if ( null !== $max_num_pages ) {
+			return $max_num_pages;
+		}
+
+		$term_count = wp_count_terms( $taxonomy, $this->get_taxonomies_query_args( $taxonomy ) );
+
+		return (int) ceil( $term_count / wp_sitemaps_get_max_urls( $this->object_type ) );
+	}
+
+	/**
+	 * Returns the query args for retrieving taxonomy terms to list in the sitemap.
+	 *
+	 * @since 5.5.0
+	 *
+	 * @param string $taxonomy Taxonomy name.
+	 * @return array Array of WP_Term_Query arguments.
+	 */
+	protected function get_taxonomies_query_args( $taxonomy ) {
+		/**
+		 * Filters the taxonomy terms query arguments.
+		 *
+		 * Allows modification of the taxonomy query arguments before querying.
+		 *
+		 * @see WP_Term_Query for a full list of arguments
+		 *
+		 * @since 5.5.0
+		 *
+		 * @param array  $args     Array of WP_Term_Query arguments.
+		 * @param string $taxonomy Taxonomy name.
+		 */
+		$args = apply_filters(
+			'wp_sitemaps_taxonomies_query_args',
+			array(
+				'fields'                 => 'ids',
+				'taxonomy'               => $taxonomy,
+				'orderby'                => 'term_order',
+				'number'                 => wp_sitemaps_get_max_urls( $this->object_type ),
+				'hide_empty'             => true,
+				'hierarchical'           => false,
+				'update_term_meta_cache' => false,
+			),
+			$taxonomy
+		);
+
+		return $args;
+	}
+}