Navigation Link block: register variations on post type / taxonomy registration

packages/block-library/src/navigation-link/index.php

@@ -322,13 +322,35 @@ function build_variation_for_navigation_link( $entity, $kind ) {
 	return $variation;
 }
 
+/**
+ * Register a variation for a post type / taxonomy for the navigation link block
+ *
+ * @param array $variation Variation array from build_variation_for_navigation_link.
+ * @return void
+ */
+function register_block_core_navigation_link_variation( $variation ) {
+	// Directly set the variations on the registered block type
+	// because there's no server side registration for variations (see #47170).
+	$navigation_block_type = WP_Block_Type_Registry::get_instance()->get_registered( 'core/navigation-link' );
+	// If the block is not registered yet, bail early.
+	// Variation will be registered in register_block_core_navigation_link then.
+	if ( ! $navigation_block_type ) {
+		return;
+	}
+
+	$navigation_block_type->variations[] = $variation;
+}
+
 /**
  * Register the navigation link block.
  *
  * @uses render_block_core_navigation()
  * @throws WP_Error An WP_Error exception parsing the block definition.
  */
 function register_block_core_navigation_link() {
+	// This will only handle post types and taxonomies registered until this point (init on priority 9).
+	// See action hooks below for other post types and taxonomies.
+	// See https://github.com/WordPress/gutenberg/issues/53826 for details.
 	$post_types = get_post_types( array( 'show_in_nav_menus' => true ), 'objects' );
 	$taxonomies = get_taxonomies( array( 'show_in_nav_menus' => true ), 'objects' );
 
@@ -369,3 +391,38 @@ function register_block_core_navigation_link() {
 	);
 }
 add_action( 'init', 'register_block_core_navigation_link' );
+// Register actions for all post types and taxonomies, to add variations when they are registered.
+// All post types/taxonomies registered before register_block_core_navigation_link, will be handled by that function.
+add_action( 'registered_post_type', 'register_block_core_navigation_link_post_type_variation', 10, 2 );
+add_action( 'registered_taxonomy', 'register_block_core_navigation_link_taxonomy_variation', 10, 3 );
+
+/**
+ * Register custom post type variations for navigation link on post type registration
+ * Handles all post types registered after the block is registered in register_navigation_link_post_type_variations
+ *
+ * @param string       $post_type The post type name passed from registered_post_type filter.
+ * @param WP_Post_Type $post_type_object The post type object passed from registered_post_type.
+ * @return void
+ */
+function register_block_core_navigation_link_post_type_variation( $post_type, $post_type_object ) {
+	if ( $post_type_object->show_in_nav_menus ) {
+		$variation = build_variation_for_navigation_link( $post_type_object, 'post-type' );
+		register_block_core_navigation_link_variation( $variation );
+	}
+}
+
+/**
+ * Register a custom taxonomy variation for navigation link on taxonomy registration
+ * Handles all taxonomies registered after the block is registered in register_navigation_link_post_type_variations
+ *
+ * @param string       $taxonomy Taxonomy slug.
+ * @param array|string $object_type Object type or array of object types.
+ * @param array        $args Array of taxonomy registration arguments.
+ * @return void
+ */
+function register_block_core_navigation_link_taxonomy_variation( $taxonomy, $object_type, $args ) {
+	if ( isset( $args['show_in_nav_menus'] ) && $args['show_in_nav_menus'] ) {
+		$variation = build_variation_for_navigation_link( (object) $args, 'post-type' );
+		register_block_core_navigation_link_variation( $variation );
+	}
+}

phpunit/blocks/block-navigation-link-variations-test.php

@@ -0,0 +1,89 @@
+<?php
+/**
+ * Navigation block rendering tests.
+ *
+ * @package WordPress
+ * @subpackage Blocks
+ */
+
+/**
+ * Tests for the Navigation block variations for post types.
+ *
+ * @group blocks
+ */
+class Block_Navigation_Link_Variations_Test extends WP_UnitTestCase {
+	public function set_up() {
+		parent::set_up();
+		register_post_type(
+			'custom_book',
+			array(
+				'labels'            => array(
+					'item_link' => 'Custom Book',
+				),
+				'public'            => true,
+				'show_in_rest'      => true,
+				'show_in_nav_menus' => true,
+			)
+		);
+		register_taxonomy(
+			'book_type',
+			'custom_book',
+			array(
+				'labels'            => array(
+					'item_link' => 'Book Type',
+				),
+				'show_in_nav_menus' => true,
+			)
+		);
+	}
+
+	public function tear_down() {
+		unregister_post_type( 'custom_book' );
+		unregister_taxonomy( 'book_type' );
+		parent::tear_down();
+	}
+
+	/**
+	 * @covers ::register_block_core_navigation_link_post_type_variation
+	 */
+	public function test_navigation_link_variations_custom_post_type() {
+		$registry       = WP_Block_Type_Registry::get_instance();
+		$nav_link_block = $registry->get_registered( 'core/navigation-link' );
+		$this->assertNotEmpty( $nav_link_block->variations, 'Block has no variations' );
+		$variation = $this->get_variation_by_name( 'custom_book', $nav_link_block->variations );
+		$this->assertIsArray( $variation, 'Block variation is not an array' );
+		$this->assertArrayHasKey( 'title', $variation, 'Block variation has no title' );
+		$this->assertEquals( 'Custom Book', $variation['title'], 'Variation title is different than the post type label' );
+	}
+
+	/**
+	 * @covers ::register_block_core_navigation_link_taxonomy_variation
+	 */
+	public function test_navigation_link_variations_custom_taxonomy() {
+		$registry       = WP_Block_Type_Registry::get_instance();
+		$nav_link_block = $registry->get_registered( 'core/navigation-link' );
+		$this->assertNotEmpty( $nav_link_block->variations, 'Block has no variations' );
+		$variation = $this->get_variation_by_name( 'book_type', $nav_link_block->variations );
+		$this->assertIsArray( $variation, 'Block variation is not an array' );
+		$this->assertArrayHasKey( 'title', $variation, 'Block variation has no title' );
+		$this->assertEquals( 'Book Type', $variation['title'], 'Variation title is different than the post type label' );
+	}
+
+	/**
+	 * Get a variation by its name from an array of variations.
+	 *
+	 * @param string $variation_name The name (= slug) of the variation.
+	 * @param array  $variations An array of variations.
+	 * @return array|null The found variation or null.
+	 */
+	private function get_variation_by_name( $variation_name, $variations ) {
+		$found_variation = null;
+		foreach ( $variations as $variation ) {
+			if ( $variation['name'] === $variation_name ) {
+				$found_variation = $variation;
+			}
+		}
+
+		return $found_variation;
+	}
+}