Navigation link: prime caches for all posts in menu items

lib/compat/wordpress-6.1/navigation.php

@@ -0,0 +1,40 @@
+<?php
+/**
+ * Temporary compatibility shims for navigation block.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Iterate through all inner blocks recursively and get navigation link block's post ids..
+ *
+ * @param WP_Block_List $inner_blocks Block list class instance.
+ *
+ * @return array Array of post ids.
+ */
+function block_core_navigation_get_post_ids( $inner_blocks ) {
+	$post_ids = array_map( 'block_core_navigation_get_post_ids_from_block', iterator_to_array( $inner_blocks ) );
+	return array_unique( array_merge( ...$post_ids ) );
+}
+
+/**
+ * Get post ids from a navigation link block instance.
+ *
+ * @param WP_Block $block Instance of a block.
+ *
+ * @return array Array of post ids.
+ */
+function block_core_navigation_get_post_ids_from_block( $block ) {
+	$post_ids = array();
+
+	if ( $block->inner_blocks ) {
+		$post_ids = block_core_navigation_get_post_ids( $block->inner_blocks );
+	}
+	if ( 'core/navigation-link' === $block->name || 'core/navigation-submenu' === $block->name ) {
+		if ( $block->attributes && isset( $block->attributes['kind'] ) && 'post-type' === $block->attributes['kind'] ) {
+			$post_ids[] = $block->attributes['id'];
+		}
+	}
+
+	return $post_ids;
+}

lib/load.php

@@ -125,6 +125,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 
 // WordPress 6.1 compat.
 require __DIR__ . '/compat/wordpress-6.1/blocks.php';
+require __DIR__ . '/compat/wordpress-6.1/navigation.php';
 require __DIR__ . '/compat/wordpress-6.1/persisted-preferences.php';
 
 // Experimental features.

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

@@ -506,6 +506,11 @@ function render_block_core_navigation( $attributes, $content, $block ) {
 		$text_decoration ? array( $text_decoration_class ) : array()
 	);
 
+	$post_ids = block_core_navigation_get_post_ids( $inner_blocks );
+	if ( $post_ids ) {
+		_prime_post_caches( $post_ids, false, false );
+	}
+
 	$inner_blocks_html = '';
 	$is_list_open      = false;
 	foreach ( $inner_blocks as $inner_block ) {

phpunit/blocks/render-block-navigation-test.php

@@ -0,0 +1,34 @@
+<?php
+
+class Render_Block_Navigation_Test extends WP_UnitTestCase {
+
+	/**
+	 * @covers ::block_core_navigation_get_post_ids_from_block
+	 */
+	public function test_block_core_navigation_get_post_ids_from_block() {
+		$parsed_blocks = parse_blocks(
+			'<!-- wp:navigation-link {"label":"Sample Page","type":"page","kind":"post-type","id":755,"url":"http://localhost:8888/?page_id=755"} /-->'
+		);
+		$parsed_block  = $parsed_blocks[0];
+		$context       = array();
+		$block         = new WP_Block( $parsed_block, $context, $this->registry );
+
+		$post_ids = block_core_navigation_get_post_ids_from_block( $block );
+		$this->assertEqualSets( array( 755 ), $post_ids );
+	}
+
+	/**
+	 * @covers ::block_core_navigation_get_post_ids_from_block
+	 */
+	public function test_block_core_navigation_get_post_ids_from_block_with_submenu() {
+		$parsed_blocks = parse_blocks( '<!-- wp:navigation-submenu {"label":"Test","type":"post","id":789,"url":"http://localhost/blog/test-3","kind":"post-type","isTopLevelItem":true} -->\n<!-- wp:navigation-link {"label":"(no title)","type":"post","id":755,"url":"http://localhost/blog/755","kind":"post-type","isTopLevelLink":false} /-->\n<!-- /wp:navigation-submenu -->' );
+		$parsed_block  = $parsed_blocks[0];
+		$context       = array();
+		$block         = new WP_Block( $parsed_block, $context, $this->registry );
+
+		$post_ids = block_core_navigation_get_post_ids_from_block( $block );
+		$this->assertEqualSets( array( 755, 789 ), $post_ids );
+	}
+
+
+}