--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/rest-api/endpoints/class-wp-rest-block-renderer-controller.php	Mon Oct 14 18:28:13 2019 +0200
@@ -0,0 +1,178 @@
+<?php
+/**
+ * Block Renderer REST API: WP_REST_Block_Renderer_Controller class
+ *
+ * @package WordPress
+ * @subpackage REST_API
+ * @since 5.0.0
+ */
+
+/**
+ * Controller which provides REST endpoint for rendering a block.
+ *
+ * @since 5.0.0
+ *
+ * @see WP_REST_Controller
+ */
+class WP_REST_Block_Renderer_Controller extends WP_REST_Controller {
+
+	/**
+	 * Constructs the controller.
+	 *
+	 * @since 5.0.0
+	 */
+	public function __construct() {
+		$this->namespace = 'wp/v2';
+		$this->rest_base = 'block-renderer';
+	}
+
+	/**
+	 * Registers the necessary REST API routes, one for each dynamic block.
+	 *
+	 * @since 5.0.0
+	 */
+	public function register_routes() {
+		$block_types = WP_Block_Type_Registry::get_instance()->get_all_registered();
+
+		foreach ( $block_types as $block_type ) {
+			if ( ! $block_type->is_dynamic() ) {
+				continue;
+			}
+
+			register_rest_route(
+				$this->namespace,
+				'/' . $this->rest_base . '/(?P<name>' . $block_type->name . ')',
+				array(
+					'args'   => array(
+						'name' => array(
+							'description' => __( 'Unique registered name for the block.' ),
+							'type'        => 'string',
+						),
+					),
+					array(
+						'methods'             => WP_REST_Server::READABLE,
+						'callback'            => array( $this, 'get_item' ),
+						'permission_callback' => array( $this, 'get_item_permissions_check' ),
+						'args'                => array(
+							'context'    => $this->get_context_param( array( 'default' => 'view' ) ),
+							'attributes' => array(
+								/* translators: %s is the name of the block */
+								'description'          => sprintf( __( 'Attributes for %s block' ), $block_type->name ),
+								'type'                 => 'object',
+								'additionalProperties' => false,
+								'properties'           => $block_type->get_attributes(),
+								'default'              => array(),
+							),
+							'post_id'    => array(
+								'description' => __( 'ID of the post context.' ),
+								'type'        => 'integer',
+							),
+						),
+					),
+					'schema' => array( $this, 'get_public_item_schema' ),
+				)
+			);
+		}
+	}
+
+	/**
+	 * Checks if a given request has access to read blocks.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param WP_REST_Request $request Request.
+	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
+	 */
+	public function get_item_permissions_check( $request ) {
+		global $post;
+
+		$post_id = isset( $request['post_id'] ) ? intval( $request['post_id'] ) : 0;
+
+		if ( 0 < $post_id ) {
+			$post = get_post( $post_id );
+
+			if ( ! $post || ! current_user_can( 'edit_post', $post->ID ) ) {
+				return new WP_Error(
+					'block_cannot_read',
+					__( 'Sorry, you are not allowed to read blocks of this post.' ),
+					array(
+						'status' => rest_authorization_required_code(),
+					)
+				);
+			}
+		} else {
+			if ( ! current_user_can( 'edit_posts' ) ) {
+				return new WP_Error(
+					'block_cannot_read',
+					__( 'Sorry, you are not allowed to read blocks as this user.' ),
+					array(
+						'status' => rest_authorization_required_code(),
+					)
+				);
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Returns block output from block's registered render_callback.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+	 */
+	public function get_item( $request ) {
+		global $post;
+
+		$post_id = isset( $request['post_id'] ) ? intval( $request['post_id'] ) : 0;
+
+		if ( 0 < $post_id ) {
+			$post = get_post( $post_id );
+
+			// Set up postdata since this will be needed if post_id was set.
+			setup_postdata( $post );
+		}
+		$registry = WP_Block_Type_Registry::get_instance();
+		$block    = $registry->get_registered( $request['name'] );
+
+		if ( null === $block ) {
+			return new WP_Error(
+				'block_invalid',
+				__( 'Invalid block.' ),
+				array(
+					'status' => 404,
+				)
+			);
+		}
+
+		$data = array(
+			'rendered' => $block->render( $request->get_param( 'attributes' ) ),
+		);
+		return rest_ensure_response( $data );
+	}
+
+	/**
+	 * Retrieves block's output schema, conforming to JSON Schema.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @return array Item schema data.
+	 */
+	public function get_item_schema() {
+		return array(
+			'$schema'    => 'http://json-schema.org/schema#',
+			'title'      => 'rendered-block',
+			'type'       => 'object',
+			'properties' => array(
+				'rendered' => array(
+					'description' => __( 'The rendered block.' ),
+					'type'        => 'string',
+					'required'    => true,
+					'context'     => array( 'edit' ),
+				),
+			),
+		);
+	}
+}