feat: Add support for CoreNavigation blocks

.changeset/thirty-ducks-check.md

@@ -0,0 +1,58 @@
+---
+"@wpengine/wp-graphql-content-blocks": patch
+---
+
+Adds support for resolving and returning navigation items within the CoreNavigation block for WPGraphQL Content Blocks.
+
+```graphql
+{
+  posts {
+    nodes {
+      editorBlocks {
+        ... on CoreNavigation {
+          renderedHtml
+          navigationItems {
+            name
+            ... on CoreNavigationLink {
+              attributes {
+                url
+              }
+            }
+          }
+          attributes {
+            ref
+          }
+        }
+      }
+    }
+  }
+}
+```
+```json
+{
+  "data": {
+    "posts": {
+      "nodes": [
+        {
+          "editorBlocks": [
+            {
+              "renderedHtml": "<nav>...</nav>",
+              "navigationItems": [
+                {
+                  "name": "core/navigation-link",
+                  "attributes": {
+                    "url": "http://example.com"
+                  }
+                }
+              ],
+              "attributes": {
+                "ref": 42
+              }
+            }
+          ]
+        }
+      ]
+    }
+  }
+}
+```

includes/Blocks/CoreNavigation.php

@@ -0,0 +1,78 @@
+<?php
+/**
+ * Core Navigation Block
+ *
+ * @package WPGraphQL\ContentBlocks\Blocks
+ */
+
+namespace WPGraphQL\ContentBlocks\Blocks;
+
+use WPGraphQL\ContentBlocks\Registry\Registry;
+use WP_Block_Type;
+
+/**
+ * Class CoreNavigation
+ */
+class CoreNavigation extends Block {
+	/**
+	 * Block constructor.
+	 *
+	 * @param \WP_Block_Type                             $block The Block Type.
+	 * @param \WPGraphQL\ContentBlocks\Registry\Registry $block_registry The instance of the WPGraphQL block registry.
+	 */
+	public function __construct( WP_Block_Type $block, Registry $block_registry ) {
+		parent::__construct( $block, $block_registry );
+
+		// Register the navigationItems field
+		register_graphql_field(
+			$this->type_name,
+			'navigationItems',
+			[
+				'type'        => [ 'list_of' => 'EditorBlock' ],
+				'description' => __( 'Navigation menu items from the referenced navigation post', 'wp-graphql-content-blocks' ),
+				'resolve'     => [ $this, 'resolve_navigation_items' ],
+			]
+		);
+	}
+
+	/**
+	 * Resolve navigation items from the navigation post reference
+	 *
+	 * @param array $block The block data.
+	 * @return array|null
+	 */
+	public function resolve_navigation_items( $block ) {
+		$attributes = $block['attrs'] ?? [];
+		$ref        = $attributes['ref'] ?? null;
+
+		if ( ! $ref ) {
+			return null;
+		}
+
+		$navigation_post = get_post( $ref );
+		if ( ! $navigation_post || 'publish' !== $navigation_post->post_status ) {
+			return [];
+		}
+
+		$parsed_blocks = parse_blocks( $navigation_post->post_content );
+		return self::filter_out_empty_blocks( $parsed_blocks );
+	}
+
+	/**
+	 * Filter out empty blocks from the parsed blocks.
+	 *
+	 * @param array $parsed_blocks An array of parsed block data.
+	 * @return array An array of filtered blocks.
+	 */
+	private static function filter_out_empty_blocks( array $parsed_blocks ): array {
+		$filtered = array_filter(
+			$parsed_blocks,
+			static function ( $block ) {
+				return isset( $block['blockName'] );
+			}
+		);
+
+		// Reset keys.
+		return array_values( $filtered );
+	}
+}