Add link-target and auto-redirect options to booking/login blocks

The booking block gains a loginPageId attribute choosing which page its
logged-out "log in to book a lesson" link points to (default remains the
WordPress login screen), and the student-login block gains a
bookingPageId attribute controlling the logged-in "View available
lessons" link and the post-login redirect target (default remains the
current page). Both blocks also gain an autoRedirect toggle, off by
default, that sends the visitor straight to the target page; block
rendering starts after output, so the redirect runs on
template_redirect by parsing the queried page's content for the block,
with a self-target guard against redirect loops. The link targets are
also available to the shortcodes as login_page_id/booking_page_id.

Also fixes a pre-existing fatal: WordPress passes an empty string (not
an array) to shortcode callbacks when a shortcode is used without
attributes, so bare [us_booking] etc. threw a TypeError against the
strictly-typed render(array $atts) methods. ShortcodeRegistrar now
wraps each callback to normalize non-array attribute values.

Closes #51

Co-Authored-By: Claude Fable 5 <[email protected]>

src/BlockRegistrar.php

@@ -32,15 +32,17 @@ class BlockRegistrar {
 
 	public function register(): void {
 		add_action( 'init', [ $this, 'registerBlocks' ] );
+		add_action( 'template_redirect', [ $this, 'maybeAutoRedirect' ] );
 	}
 
 	public function registerBlocks(): void {
 		// The editor script registers the client side of each block (title,
-		// icon, shortcode transform) and previews it via wp.serverSideRender.
+		// icon, shortcode transform, inspector controls) and previews it via
+		// wp.serverSideRender.
 		wp_register_script(
 			self::SCRIPT_HANDLE,
 			USC_PLUGIN_URL . 'assets/js/blocks.js',
-			[ 'wp-blocks', 'wp-element', 'wp-block-editor', 'wp-server-side-render', 'wp-i18n' ],
+			[ 'wp-blocks', 'wp-element', 'wp-block-editor', 'wp-components', 'wp-data', 'wp-core-data', 'wp-server-side-render', 'wp-i18n' ],
 			USC_VERSION,
 			true
 		);
@@ -52,67 +54,196 @@ class BlockRegistrar {
 			wp_register_style( self::STYLE_HANDLE, USC_PLUGIN_URL . 'assets/css/frontend.css', [], USC_VERSION );
 		}
 
-		foreach ( $this->blocks() as $name => $renderCallback ) {
+		foreach ( $this->blocks() as $name => $config ) {
 			register_block_type(
 				$name,
 				[
 					'api_version'     => '3',
 					'editor_script'   => self::SCRIPT_HANDLE,
 					'style'           => self::STYLE_HANDLE,
-					'render_callback' => $renderCallback,
+					'attributes'      => $config['attributes'],
+					'render_callback' => $config['render'],
 				]
 			);
 		}
 	}
 
 	/**
-	 * Block names mapped to their render callbacks.
+	 * Block definitions: render callback plus the attribute schema. The
+	 * schema must be declared server-side too, or the block-renderer preview
+	 * endpoint rejects the attributes wp.serverSideRender sends.
 	 *
-	 * @return array<string, callable(array<string, mixed>): string>
+	 * @return array<string, array{render: callable(array<string, mixed>=): string, attributes: array<string, array{type: string, default: mixed}>}>
 	 */
 	private function blocks(): array {
+		$redirectToggle = [
+			'type'    => 'boolean',
+			'default' => false,
+		];
+
 		return [
-			'us-scheduler/booking'          => [ $this, 'renderBooking' ],
-			'us-scheduler/student-login'    => [ $this, 'renderLogin' ],
-			'us-scheduler/student-register' => [ $this, 'renderRegistration' ],
-			'us-scheduler/group-classes'    => [ $this, 'renderGroupClasses' ],
+			'us-scheduler/booking'          => [
+				'render'     => [ $this, 'renderBooking' ],
+				'attributes' => [
+					'loginPageId'  => [
+						'type'    => 'number',
+						'default' => 0,
+					],
+					'autoRedirect' => $redirectToggle,
+				],
+			],
+			'us-scheduler/student-login'    => [
+				'render'     => [ $this, 'renderLogin' ],
+				'attributes' => [
+					'bookingPageId' => [
+						'type'    => 'number',
+						'default' => 0,
+					],
+					'autoRedirect'  => $redirectToggle,
+				],
+			],
+			'us-scheduler/student-register' => [
+				'render'     => [ $this, 'renderRegistration' ],
+				'attributes' => [],
+			],
+			'us-scheduler/group-classes'    => [
+				'render'     => [ $this, 'renderGroupClasses' ],
+				'attributes' => [],
+			],
 		];
 	}
 
 	/**
 	 * Renders the booking block.
 	 *
-	 * @param array<string, mixed> $attributes Block attributes (unused — the blocks have none yet).
+	 * @param array<string, mixed> $attributes Block attributes.
 	 */
-	public function renderBooking( array $attributes = [] ): string { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
-		return $this->isEditorPreview() ? BlockPreview::booking() : $this->bookingPage->render( [] );
+	public function renderBooking( array $attributes = [] ): string {
+		return $this->isEditorPreview() ? BlockPreview::booking() : $this->bookingPage->render( $attributes );
 	}
 
 	/**
 	 * Renders the student-login block.
 	 *
-	 * @param array<string, mixed> $attributes Block attributes (unused — the blocks have none yet).
+	 * @param array<string, mixed> $attributes Block attributes.
 	 */
-	public function renderLogin( array $attributes = [] ): string { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
-		return $this->isEditorPreview() ? BlockPreview::login() : $this->loginPage->render( [] );
+	public function renderLogin( array $attributes = [] ): string {
+		return $this->isEditorPreview() ? BlockPreview::login() : $this->loginPage->render( $attributes );
 	}
 
 	/**
 	 * Renders the student-registration block.
 	 *
-	 * @param array<string, mixed> $attributes Block attributes (unused — the blocks have none yet).
+	 * @param array<string, mixed> $attributes Block attributes.
 	 */
-	public function renderRegistration( array $attributes = [] ): string { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
-		return $this->isEditorPreview() ? BlockPreview::registration() : $this->registrationPage->render( [] );
+	public function renderRegistration( array $attributes = [] ): string {
+		return $this->isEditorPreview() ? BlockPreview::registration() : $this->registrationPage->render( $attributes );
 	}
 
 	/**
 	 * Renders the group-classes block.
 	 *
-	 * @param array<string, mixed> $attributes Block attributes (unused — the blocks have none yet).
+	 * @param array<string, mixed> $attributes Block attributes.
 	 */
-	public function renderGroupClasses( array $attributes = [] ): string { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
-		return $this->isEditorPreview() ? BlockPreview::groupClasses() : $this->groupClassPage->render( [] );
+	public function renderGroupClasses( array $attributes = [] ): string {
+		return $this->isEditorPreview() ? BlockPreview::groupClasses() : $this->groupClassPage->render( $attributes );
+	}
+
+	/**
+	 * Server-side auto-redirect for blocks that opt in via their autoRedirect
+	 * attribute: logged-out visitors on a page containing the booking block
+	 * are sent to its login page, and logged-in visitors on a page containing
+	 * the student-login block are sent to its booking page. Hooked on
+	 * `template_redirect` because block rendering happens after output has
+	 * started, too late to send a Location header.
+	 */
+	public function maybeAutoRedirect(): void {
+		if ( is_admin() || ! is_singular() ) {
+			return;
+		}
+
+		$post = get_post();
+		if ( ! $post instanceof \WP_Post ) {
+			return;
+		}
+
+		if ( is_user_logged_in() ) {
+			$attrs = $this->firstBlockAttrs( $post->post_content, 'us-scheduler/student-login' );
+			if ( null === $attrs || ! Val::bool( $attrs['autoRedirect'] ?? false ) ) {
+				return;
+			}
+
+			$bookingPageId = Val::int( $attrs['bookingPageId'] ?? 0 );
+			if ( $bookingPageId === $post->ID ) {
+				return; // Redirecting the page to itself would loop.
+			}
+
+			$url = $this->loginPage->bookingUrl( $bookingPageId );
+			if ( null !== $url ) {
+				$this->redirect( $url );
+			}
+
+			return;
+		}
+
+		$attrs = $this->firstBlockAttrs( $post->post_content, 'us-scheduler/booking' );
+		if ( null === $attrs || ! Val::bool( $attrs['autoRedirect'] ?? false ) ) {
+			return;
+		}
+
+		$loginPageId = Val::int( $attrs['loginPageId'] ?? 0 );
+		if ( $loginPageId === $post->ID ) {
+			return; // Redirecting the page to itself would loop.
+		}
+
+		$this->redirect( $this->bookingPage->loginUrl( $loginPageId ) );
+	}
+
+	/**
+	 * Attributes of the first occurrence of the named block in the content,
+	 * searching inner blocks so blocks nested inside groups or columns are
+	 * still found. Null when the block is absent. Attributes equal to their
+	 * schema default are omitted from the serialized block, so callers must
+	 * apply defaults themselves.
+	 *
+	 * @return array<mixed>|null
+	 */
+	private function firstBlockAttrs( string $content, string $blockName ): ?array {
+		if ( ! has_block( $blockName, $content ) ) {
+			return null;
+		}
+
+		$queue = parse_blocks( $content );
+
+		while ( [] !== $queue ) {
+			$block = array_shift( $queue );
+
+			if ( ! is_array( $block ) ) {
+				continue;
+			}
+
+			if ( ( $block['blockName'] ?? null ) === $blockName ) {
+				$attrs = $block['attrs'] ?? null;
+
+				return is_array( $attrs ) ? $attrs : [];
+			}
+
+			$inner = $block['innerBlocks'] ?? null;
+			if ( is_array( $inner ) && [] !== $inner ) {
+				$queue = array_merge( $queue, array_values( $inner ) );
+			}
+		}
+
+		return null;
+	}
+
+	/**
+	 * Issues the redirect and stops the request. Split out so tests can
+	 * observe redirects without the process exiting.
+	 */
+	protected function redirect( string $url ): void {
+		wp_safe_redirect( $url );
+		exit;
 	}
 
 	/**