Serve the aggregated schema map at /schemamap.xml

src/schema-aggregator/application/schema_map/schema-map-xml-provider.php

@@ -0,0 +1,73 @@
+<?php
+// phpcs:disable Yoast.NamingConventions.NamespaceName.TooLong -- Needed in the folder structure.
+namespace Yoast\WP\SEO\Schema_Aggregator\Application\Schema_Map;
+
+use Yoast\WP\SEO\Schema_Aggregator\Application\Aggregate_Site_Schema_Map_Command;
+use Yoast\WP\SEO\Schema_Aggregator\Application\Aggregate_Site_Schema_Map_Command_Handler;
+use Yoast\WP\SEO\Schema_Aggregator\Application\Cache\Xml_Manager;
+use Yoast\WP\SEO\Schema_Aggregator\Infrastructure\Aggregator_Config;
+
+/**
+ * Provides the schema map XML, building and caching it when needed.
+ */
+class Schema_Map_Xml_Provider {
+
+	/**
+	 * The command handler instance.
+	 *
+	 * @var Aggregate_Site_Schema_Map_Command_Handler
+	 */
+	private $aggregate_site_schema_map_command_handler;
+
+	/**
+	 * The XML cache manager instance.
+	 *
+	 * @var Xml_Manager
+	 */
+	private $xml_cache_manager;
+
+	/**
+	 * The aggregator configuration instance.
+	 *
+	 * @var Aggregator_Config
+	 */
+	private $aggregator_config;
+
+	/**
+	 * Schema_Map_Xml_Provider constructor.
+	 *
+	 * @param Aggregate_Site_Schema_Map_Command_Handler $aggregate_site_schema_map_command_handler The command handler.
+	 * @param Xml_Manager                               $xml_cache_manager                         The XML cache
+	 *                                                                                             manager.
+	 * @param Aggregator_Config                         $aggregator_config                         The aggregator
+	 *                                                                                             configuration.
+	 */
+	public function __construct(
+		Aggregate_Site_Schema_Map_Command_Handler $aggregate_site_schema_map_command_handler,
+		Xml_Manager $xml_cache_manager,
+		Aggregator_Config $aggregator_config
+	) {
+		$this->aggregate_site_schema_map_command_handler = $aggregate_site_schema_map_command_handler;
+		$this->xml_cache_manager                         = $xml_cache_manager;
+		$this->aggregator_config                         = $aggregator_config;
+	}
+
+	/**
+	 * Returns the schema map XML, building and caching it when it is not cached yet.
+	 *
+	 * @return string The schema map XML.
+	 */
+	public function get_xml(): string {
+		$cached_xml = $this->xml_cache_manager->get();
+		if ( $cached_xml !== null ) {
+			return $cached_xml;
+		}
+
+		$command = new Aggregate_Site_Schema_Map_Command( $this->aggregator_config->get_allowed_post_types() );
+		$xml     = $this->aggregate_site_schema_map_command_handler->handle( $command );
+
+		$this->xml_cache_manager->set( $xml );
+
+		return $xml;
+	}
+}

src/schema-aggregator/user-interface/schemamap-xml-rewrite-integration.php

@@ -0,0 +1,195 @@
+<?php
+// phpcs:disable Yoast.NamingConventions.NamespaceName.TooLong -- Needed in the folder structure.
+namespace Yoast\WP\SEO\Schema_Aggregator\User_Interface;
+
+use WP_Query;
+use Yoast\WP\SEO\Conditionals\Front_End_Conditional;
+use Yoast\WP\SEO\Helpers\Redirect_Helper;
+use Yoast\WP\SEO\Integrations\Integration_Interface;
+use Yoast\WP\SEO\Schema_Aggregator\Application\Schema_Map\Schema_Map_Xml_Provider;
+use Yoast\WP\SEO\Schema_Aggregator\Infrastructure\Schema_Aggregator_Conditional;
+use Yoast_Dynamic_Rewrites;
+
+/**
+ * Serves the schema map at the `schemamap.xml` path of the site.
+ *
+ * @phpcs:disable Yoast.NamingConventions.ObjectNameDepth.MaxExceeded
+ */
+class Schemamap_Xml_Rewrite_Integration implements Integration_Interface {
+
+	/**
+	 * The query variable that flags a request for the schema map.
+	 *
+	 * @var string
+	 */
+	public const QUERY_VAR = 'yoast_schemamap';
+
+	/**
+	 * The schema map XML provider.
+	 *
+	 * @var Schema_Map_Xml_Provider
+	 */
+	private $schema_map_xml_provider;
+
+	/**
+	 * The redirect helper.
+	 *
+	 * @var Redirect_Helper
+	 */
+	private $redirect_helper;
+
+	/**
+	 * Returns the conditionals for this integration.
+	 *
+	 * The front end conditional keeps the rewrite rule out of admin requests, where the schema map is
+	 * never served. It also means the rule is absent while Yoast SEO is being deactivated, so no
+	 * equivalent of the `Deactivating_Yoast_Seo_Conditional` guard in `WPSEO_Sitemaps_Router` is needed.
+	 *
+	 * @return array<string> The conditionals that must be met to load this.
+	 */
+	public static function get_conditionals() {
+		return [ Schema_Aggregator_Conditional::class, Front_End_Conditional::class ];
+	}
+
+	/**
+	 * Schemamap_Xml_Rewrite_Integration constructor.
+	 *
+	 * @param Schema_Map_Xml_Provider $schema_map_xml_provider The schema map XML provider.
+	 * @param Redirect_Helper         $redirect_helper         The redirect helper.
+	 */
+	public function __construct( Schema_Map_Xml_Provider $schema_map_xml_provider, Redirect_Helper $redirect_helper ) {
+		$this->schema_map_xml_provider = $schema_map_xml_provider;
+		$this->redirect_helper         = $redirect_helper;
+	}
+
+	/**
+	 * Registers the hooks for the integration.
+	 *
+	 * The schema map is rendered on `pre_get_posts` rather than `template_redirect`, the same way
+	 * `WPSEO_Sitemaps::redirect()` renders sitemaps. That skips the main posts query, which this
+	 * response never uses, and leaves fewer third-party callbacks able to echo ahead of the XML —
+	 * anything printed before the document would stop it parsing as a sitemap.
+	 *
+	 * @return void
+	 */
+	public function register_hooks() {
+		/*
+		 * Integrations register their hooks on `init` priority 10, which is after
+		 * `yoast_add_dynamic_rewrite_rules` has already fired on `init` priority 1. The rule is
+		 * therefore added directly, the same way `WPSEO_Sitemaps::register_sitemap()` does for
+		 * sitemaps registered during `init`. Rewrite rules are not read until `WP::parse_request()`,
+		 * so this is still in time.
+		 */
+		$this->add_rewrite_rules( Yoast_Dynamic_Rewrites::instance() );
+
+		\add_filter( 'query_vars', [ $this, 'add_query_vars' ] );
+		\add_action( 'pre_get_posts', [ $this, 'maybe_render_schema_map' ], 1 );
+	}
+
+	/**
+	 * Adds the rewrite rule for the schema map.
+	 *
+	 * @param Yoast_Dynamic_Rewrites $dynamic_rewrites Dynamic rewrites handler instance.
+	 *
+	 * @return void
+	 */
+	public function add_rewrite_rules( Yoast_Dynamic_Rewrites $dynamic_rewrites ) {
+		$dynamic_rewrites->add_rule( 'schemamap\.xml$', 'index.php?' . self::QUERY_VAR . '=1', 'top' );
+	}
+
+	/**
+	 * Adds the query variable for the schema map.
+	 *
+	 * @param array<string> $query_vars List of query variables to filter.
+	 *
+	 * @return array<string> Filtered query variables.
+	 */
+	public function add_query_vars( $query_vars ) {
+		$query_vars[] = self::QUERY_VAR;
+
+		return $query_vars;
+	}
+
+	/**
+	 * Outputs the schema map when the main query is a request for it.
+	 *
+	 * @param WP_Query $query The query that is about to run.
+	 *
+	 * @return void
+	 */
+	public function maybe_render_schema_map( WP_Query $query ) {
+		if ( ! $query->is_main_query() || ! $query->get( self::QUERY_VAR ) ) {
+			return;
+		}
+
+		/*
+		 * Without control over the headers the response cannot be typed as XML, and echoing the
+		 * document into a half-written HTML body would produce neither a page nor a schema map.
+		 */
+		if ( $this->headers_already_sent() ) {
+			return;
+		}
+
+		/*
+		 * Build the document before committing any headers. Generating it hits the database and can
+		 * throw, and a failure after the 200 and the cache headers were sent would let a proxy store
+		 * an HTML error page at this path for the full max-age.
+		 */
+		$xml = $this->schema_map_xml_provider->get_xml();
+
+		$this->send_headers();
+
+		// DOMDocument::createTextNode() already escaped every value; escaping again would corrupt the XML.
+		echo $xml; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- Raw XML.
+
+		$this->finish_request();
+	}
+
+	/**
+	 * Sends the response headers for the schema map.
+	 *
+	 * These replace what `WP::send_headers()` already sent: the HTML content type, and the `Expires`
+	 * and `Cache-Control` pair that `wp_get_nocache_headers()` adds for logged-in users.
+	 *
+	 * @return void
+	 */
+	protected function send_headers() {
+		\status_header( 200 );
+		// Prevent the search engines from indexing the schema map.
+		$this->redirect_helper->set_header( 'X-Robots-Tag: noindex, follow' );
+		$this->redirect_helper->set_header( 'Content-Type: application/xml; charset=UTF-8' );
+		$this->redirect_helper->set_header( 'Cache-Control: public, max-age=300' );
+		// The response is public, so the no-cache Expires date from wp_get_nocache_headers() must go.
+		$this->redirect_helper->remove_header( 'Expires' );
+	}
+
+	/**
+	 * Tells whether the response headers have already been sent.
+	 *
+	 * Wrapped in an overridable method so the unit tests can drive both branches of
+	 * maybe_render_schema_map(); the test process cannot control what headers_sent() reports.
+	 * Protected rather than private because Mockery cannot stub private methods.
+	 *
+	 * @codeCoverageIgnore It only wraps a PHP function.
+	 *
+	 * @return bool Whether the headers have already been sent.
+	 */
+	protected function headers_already_sent(): bool {
+		return \headers_sent();
+	}
+
+	/**
+	 * Ends the request after the schema map has been output.
+	 *
+	 * The exit() is wrapped in an overridable method so the unit tests can stub it out; executing it
+	 * would terminate the test runner. Protected rather than private because Mockery cannot stub
+	 * private methods.
+	 *
+	 * @codeCoverageIgnore It only wraps a language construct that terminates the request.
+	 *
+	 * @return void
+	 */
+	protected function finish_request() {
+		exit();
+	}
+}

src/schema-aggregator/user-interface/site-schema-aggregator-xml-route.php

@@ -2,15 +2,10 @@
 // phpcs:disable Yoast.NamingConventions.NamespaceName.TooLong -- Needed in the folder structure.
 namespace Yoast\WP\SEO\Schema_Aggregator\User_Interface;
 
-use WP_Error;
 use WP_REST_Response;
 use Yoast\WP\SEO\Main;
 use Yoast\WP\SEO\Routes\Route_Interface;
-use Yoast\WP\SEO\Schema_Aggregator\Application\Aggregate_Site_Schema_Map_Command;
-use Yoast\WP\SEO\Schema_Aggregator\Application\Aggregate_Site_Schema_Map_Command_Handler;
-use Yoast\WP\SEO\Schema_Aggregator\Application\Cache\Xml_Manager;
-use Yoast\WP\SEO\Schema_Aggregator\Infrastructure\Aggregator_Config;
-use Yoast\WP\SEO\Schema_Aggregator\Infrastructure\Config;
+use Yoast\WP\SEO\Schema_Aggregator\Application\Schema_Map\Schema_Map_Xml_Provider;
 use Yoast\WP\SEO\Schema_Aggregator\Infrastructure\Schema_Aggregator_Conditional;
 
 /**
@@ -34,25 +29,11 @@ class Site_Schema_Aggregator_Xml_Route implements Route_Interface {
 	public const GET_SCHEMA_ROUTE = self::ROUTE_PREFIX . '/get-xml';
 
 	/**
-	 * The command handler instance.
+	 * The schema map XML provider.
 	 *
-	 * @var Aggregate_Site_Schema_Map_Command_Handler
+	 * @var Schema_Map_Xml_Provider
 	 */
-	private $aggregate_site_schema_map_command_handler;
-
-	/**
-	 * The XML cache manager instance.
-	 *
-	 * @var Xml_Manager
-	 */
-	private $xml_cache_manager;
-
-	/**
-	 * The aggregator configuration instance.
-	 *
-	 * @var Aggregator_Config
-	 */
-	private $aggregator_config;
+	private $schema_map_xml_provider;
 
 	/**
 	 * Returns the conditional for this route.
@@ -66,20 +47,10 @@ public static function get_conditionals() {
 	/**
 	 * Site_Schema_Aggregator_Route constructor.
 	 *
-	 * @param Aggregate_Site_Schema_Map_Command_Handler $aggregate_site_schema_map_command_handler The command handler.
-	 * @param Xml_Manager                               $xml_cache_manager                         The XML cache
-	 *                                                                                             manager.
-	 * @param Aggregator_Config                         $aggregator_config                         The aggregator
-	 *                                                                                             configuration.
+	 * @param Schema_Map_Xml_Provider $schema_map_xml_provider The schema map XML provider.
 	 */
-	public function __construct(
-		Aggregate_Site_Schema_Map_Command_Handler $aggregate_site_schema_map_command_handler,
-		Xml_Manager $xml_cache_manager,
-		Aggregator_Config $aggregator_config
-	) {
-		$this->aggregate_site_schema_map_command_handler = $aggregate_site_schema_map_command_handler;
-		$this->xml_cache_manager                         = $xml_cache_manager;
-		$this->aggregator_config                         = $aggregator_config;
+	public function __construct( Schema_Map_Xml_Provider $schema_map_xml_provider ) {
+		$this->schema_map_xml_provider = $schema_map_xml_provider;
 	}
 
 	/**
@@ -109,25 +80,12 @@ public function get_permission_callback(): bool {
 	}
 
 	/**
-	 * Returns a XML representation of the possible post types that can be used for schema.
+	 * Returns a XML representation of the post types that are used for schema.
 	 *
-	 * @return WP_REST_Response|WP_Error The success or failure response.
+	 * @return WP_REST_Response The response.
 	 */
 	public function render_schema_xml() {
-		$cached_xml = $this->xml_cache_manager->get();
-		if ( $cached_xml !== null ) {
-			$xml = $cached_xml;
-		}
-		else {
-
-			$post_types = $this->aggregator_config->get_allowed_post_types();
-
-			$command = new Aggregate_Site_Schema_Map_Command( $post_types );
-			$xml     = $this->aggregate_site_schema_map_command_handler->handle( $command );
-
-			$this->xml_cache_manager->set( $xml );
-		}
-		$response = new WP_REST_Response( $xml, 200 );
+		$response = new WP_REST_Response( $this->schema_map_xml_provider->get_xml(), 200 );
 		$response->header( 'Content-Type', 'application/xml; charset=UTF-8' );
 		$response->header( 'Cache-Control', 'public, max-age=300' );