Replace LYS coming soon override to use template include filter and handle 404 gracefully (#46667)

* Hide woo breadcrumb

* Update coming soon entire site style

* Update style

* Fix wp group block

* Change coming soon template to use template_include instead

* Changelog

* Change to add_filter

* Proper handling for non-FSE themes

* Update comments

---------

Co-authored-by: Chi-Hsuan Huang <chihsuan.tw@gmail.com>

plugins/woocommerce/changelog/update-LYS-use-template-include

@@ -0,0 +1,4 @@
+Significance: patch
+Type: update
+
+Update to use template_include instead, handle 404 for restrict store pages only

plugins/woocommerce/src/Internal/ComingSoon/ComingSoonRequestHandler.php

@@ -25,7 +25,7 @@ class ComingSoonRequestHandler {
 	 */
 	final public function init( ComingSoonHelper $coming_soon_helper ) {
 		$this->coming_soon_helper = $coming_soon_helper;
-		add_action( 'parse_request', array( $this, 'handle_parse_request' ) );
+		add_filter( 'template_include', array( $this, 'handle_template_include' ) );
 		add_action( 'wp_enqueue_scripts', array( $this, 'deregister_unnecessary_styles' ), 100 );
 	}
 
@@ -57,35 +57,49 @@ class ComingSoonRequestHandler {
 	}
 
 	/**
-	 * Parses the current request and sets the page ID to the coming soon page if it
+	 * Replaces the page template with a 'coming soon' when the site is in coming soon mode.
-	 * needs to be shown in place of the normal page.
 	 *
 	 * @internal
 	 *
-	 * @param \WP $wp Current WordPress environment instance (passed by reference).
+	 * @param string $template The path to the previously determined template.
+	 * @return string|null The path to the 'coming soon' template or null to prevent further template loading in FSE themes.
 	 */
-	public function handle_parse_request( \WP &$wp ) {
+	public function handle_template_include( $template ) {
+		global $wp;
+
 		if ( ! $this->should_show_coming_soon( $wp ) ) {
-			return $wp;
+			return $template;
 		}
 
 		// A coming soon page needs to be displayed. Don't cache this response.
 		nocache_headers();
+
+		// Optimize search engine by returning 503 status code and set retry-after header to 12 hours.
+		status_header( 503 );
+		header( 'Retry-After: ' . 12 * HOUR_IN_SECONDS );
+
 		add_theme_support( 'block-templates' );
 		wp_dequeue_style( 'global-styles' );
-		$template = get_query_template( 'coming-soon' );
+		$coming_soon_template = get_query_template( 'coming-soon' );
 
 		if ( ! wc_current_theme_is_fse_theme() && $this->coming_soon_helper->is_store_coming_soon() ) {
 			get_header();
 		}
 
-		include $template;
+		include $coming_soon_template;
 
 		if ( ! wc_current_theme_is_fse_theme() && $this->coming_soon_helper->is_store_coming_soon() ) {
 			get_footer();
 		}
 
-		die();
+		if ( wc_current_theme_is_fse_theme() ) {
+			// Since we've already rendered a template, return null to ensure no other template is rendered.
+			return null;
+		} else {
+			// In non-FSE themes, other templates will still be rendered.
+			// We need to exit to prevent further processing.
+			exit();
+		}
 	}
 
 	/**
@@ -106,6 +120,11 @@ class ComingSoonRequestHandler {
 			return false;
 		}
 
+		// Do not show coming soon on 404 pages when restrict to store pages only.
+		if ( $this->coming_soon_helper->is_store_coming_soon() && is_404() ) {
+			return false;
+		}
+
 		// Early exit if the URL doesn't need a coming soon screen.
 		$url = $this->coming_soon_helper->get_url_from_wp( $wp );