feat: override get_head search request metadata

wp/headless-wp/includes/classes/Integrations/YoastSEO.php

@@ -27,6 +27,12 @@ public function register() {
 		add_filter( 'wpseo_sitemap_url', array( $this, 'maybe_override_sitemap_url' ), 10, 2 );
 
 		add_filter( 'robots_txt', array( $this, 'maybe_override_sitemap_robots_url' ), 999999 );
+
+		// Override Search results yoast head, get_head endpoint currently does't detect search page.
+		add_filter( 'wpseo_canonical', array( $this, 'override_search_canonical' ), 10, 1 );
+		add_filter( 'wpseo_title', array( $this, 'override_search_title' ), 10, 1 );
+		add_filter( 'wpseo_opengraph_title', array( $this, 'override_search_title' ), 10, 1 );
+		add_filter( 'wpseo_opengraph_url', array( $this, 'override_search_canonical' ), 10, 1 );
 	}
 
 	/**
@@ -162,4 +168,114 @@ public function maybe_override_sitemap_robots_url( $output ) {
 
 		return $output;
 	}
+
+	/**
+	 * Return list of query vars if the request is /yoast/v1/get_head?url and for search URL based on ?s= parameter.
+	 *
+	 * @return boolean|array False if it's not a yoast search rest api request. Search $query_vars if otherwise.
+	 */
+	public function get_yoast_search_query_vars() {
+
+		if ( ! ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) {
+			return false;
+		}
+
+		$request_uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_url( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
+
+		if ( false === strpos( $request_uri, '/yoast/v1/get_head' ) ) {
+			return false;
+		}
+
+		$url_param = isset( $_GET['url'] ) ? sanitize_url( wp_unslash( $_GET['url'] ) ) : '';
+
+		if ( filter_var( $url_param, FILTER_VALIDATE_URL ) !== false ) {
+			$query = wp_parse_url( $url_param, PHP_URL_QUERY );
+			parse_str( $query, $query_vars );
+
+			// Return query vars if search request.
+			if ( isset( $query_vars['s'] ) ) {
+				return apply_filters( 'tenup_headless_wp_search_request_query_vars', $query_vars );
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Custom helper to replace Yoast search title placeholders.
+	 * Assuming only some of the basic variables.
+	 *
+	 * @todo Support for page number.
+	 *
+	 * @param string $title The search SEO title
+	 * @param array  $query_vars The search query vars.
+	 *
+	 * @return string
+	 */
+	public function replace_yoast_search_title_placeholders( $title, $query_vars ) {
+
+		$str_replace_mapping = apply_filters(
+			'tenup_headless_wp_search_title_variables_replacments',
+			array(
+				'%%sitename%%'     => get_bloginfo( 'name' ),
+				'%%searchphrase%%' => $query_vars['s'] ?? '',
+				' %%page%%'        => '',
+				'%%sep%%'          => \YoastSEO()->helpers->options->get_title_separator() ?? ' ',
+			)
+		);
+
+		return str_replace( array_keys( $str_replace_mapping ), array_values( $str_replace_mapping ), $title );
+	}
+
+	/**
+	 * Set the missing Yoast Search title.
+	 *
+	 * @param string $title The title.
+	 * @return string
+	 */
+	public function override_search_title( $title ) {
+
+		$search_request_query_vars = $this->get_yoast_search_query_vars();
+
+		if ( ! $search_request_query_vars ) {
+			return $title;
+		}
+
+		$wpseo_titles = get_option( 'wpseo_titles' );
+
+		$title_search_wpseo = '';
+
+		// Get user setting for search title, fallback to default search from Yoast SEO.
+		if ( ! empty( $wpseo_titles ) && ! empty( $wpseo_titles['title-search-wpseo'] ) ) {
+			$title_search_wpseo = $wpseo_titles['title-search-wpseo'];
+		} else {
+			$default_titles = \WPSEO_Option_Titles::get_instance()->get_defaults();
+			if ( ! empty( $default_titles['title-search-wpseo'] ) ) {
+				$title_search_wpseo = $default_titles['title-search-wpseo'];
+			}
+		}
+
+		if ( empty( $title_search_wpseo ) ) {
+			return $title;
+		}
+
+		return $this->replace_yoast_search_title_placeholders( $title_search_wpseo, $search_request_query_vars );
+	}
+
+	/**
+	 * Yoast doesn't  have a canonical for search and returns URL as the homepage URL. Generally https://gus.test/?s=test
+	 * But with headstartwp nextjs app usually there is a route for search page.
+	 * Default is 'search'.
+	 *
+	 * @param string $canonical The canonical URL.
+	 * @return string
+	 */
+	public function override_search_canonical( $canonical ) {
+		if ( $this->get_yoast_search_query_vars() ) {
+			$search_route = apply_filters( 'tenup_headless_wp_search_route', 'search' );
+			$canonical = rtrim( $canonical, '/' ) . '/' . $search_route;
+		}
+
+		return $canonical;
+	}
 }