Table of Contents: Add aria label to the nav element (#71586)

* Added aria label to the nav element

* fixed fixtures to include the new attr

* Update edit.js

* Update save.js

* Try server-side rendering the block

# Conflicts:
#	packages/block-library/src/table-of-contents/save.js

* Fix coding standards errors

* Simplify server-side approach

* Regenerate test fixtures

* Simplify $aria_label

* Restore test fixtures

* Revert changes to other test fixtures

* Update packages/block-library/src/table-of-contents/index.php

Co-authored-by: Aki Hamano <54422211+t-hamano@users.noreply.github.com>

---------

Co-authored-by: Sarah Norris <sarah@sekai.co.uk>
Co-authored-by: Sarah Norris <1645628+mikachan@users.noreply.github.com>
Co-authored-by: George Mamadashvili <georgemamadashvili@gmail.com>
Co-authored-by: Aki Hamano <54422211+t-hamano@users.noreply.github.com>
Co-authored-by: MaggieCabrera <onemaggie@git.wordpress.org>
Co-authored-by: mikachan <mikachan@git.wordpress.org>
Co-authored-by: Mamaduka <mamaduka@git.wordpress.org>
Co-authored-by: t-hamano <wildworks@git.wordpress.org>

Author: 5 people

docs/reference-guides/core-blocks.md

@@ -957,7 +957,7 @@ Summarize your post with a list of headings. Add HTML anchors to Heading blocks
 -	**Name:** core/table-of-contents
 -	**Experimental:** true
 -	**Category:** design
--	**Supports:** color (background, gradients, link, text), interactivity (clientNavigation), spacing (margin, padding), typography (fontSize, lineHeight), ~~html~~
+-	**Supports:** ariaLabel, color (background, gradients, link, text), interactivity (clientNavigation), spacing (margin, padding), typography (fontSize, lineHeight), ~~html~~
 -	**Attributes:** headings, maxLevel, onlyIncludeCurrentPage, ordered
 
 ## Tag Cloud

lib/blocks.php

@@ -120,6 +120,7 @@ function gutenberg_reregister_core_block_types() {
 				'site-logo.php'                    => 'core/site-logo',
 				'site-tagline.php'                 => 'core/site-tagline',
 				'site-title.php'                   => 'core/site-title',
+				'table-of-contents.php'            => 'core/table-of-contents',
 				'tag-cloud.php'                    => 'core/tag-cloud',
 				'template-part.php'                => 'core/template-part',
 				'term-description.php'             => 'core/term-description',

packages/block-library/src/table-of-contents/block.json

@@ -29,6 +29,7 @@
 		}
 	},
 	"supports": {
+		"ariaLabel": true,
 		"html": false,
 		"color": {
 			"text": true,

packages/block-library/src/table-of-contents/index.php

@@ -0,0 +1,44 @@
+<?php
+/**
+ * Server-side rendering of the `core/table-of-contents` block.
+ *
+ * @package WordPress
+ */
+
+/**
+ * Adds an aria-label to the table of contents block content.
+ *
+ * @param array  $attributes Attributes of the block being rendered.
+ * @param string $content Content of the block being rendered.
+ *
+ * @return string The content of the block being rendered.
+ */
+function block_core_table_of_contents_render( $attributes, $content ) {
+	if ( ! $content ) {
+		return $content;
+	}
+
+	// Get the aria-label from block attributes, or fallback to localized default.
+	$aria_label = empty( $attributes['ariaLabel'] ) ? __( 'Table of Contents' ) : wp_strip_all_tags( $attributes['ariaLabel'] );
+
+	$p = new WP_HTML_Tag_Processor( $content );
+
+	if ( $p->next_tag( 'nav' ) ) {
+		$p->set_attribute( 'aria-label', $aria_label );
+	}
+
+	return $p->get_updated_html();
+}
+
+/**
+ * Registers the `core/table-of-contents` block on the server.
+ */
+function register_block_core_table_of_contents() {
+	register_block_type_from_metadata(
+		__DIR__ . '/table-of-contents',
+		array(
+			'render_callback' => 'block_core_table_of_contents_render',
+		)
+	);
+}
+add_action( 'init', 'register_block_core_table_of_contents' );