Block API: Mark block global as experimental

Author: aduth

docs/designers-developers/developers/block-api/block-context.md

@@ -63,16 +63,4 @@ registerBlockType( 'my-plugin/record-title', {
 
 ### PHP
 
-Note that in PHP, block context is accessed using the `$block` global which is assigned at the time a block is rendered. This is unlike block attributes or block content, which are provided as arguments to the `render_callback` function. At some point in the future, block context may be integrated into the function arguments signature of `render_callback`, or an alternative block settings configuration may enable a render callback to receive the full block array as its argument.
-
-`record-title/index.php`
-
-```php
-register_block_type( 'my-plugin/record-title', [
-	'render_callback' => function() {
-		global $block;
-
-		return 'The current record ID is: ' . $block->context['my-plugin/recordId'];
-	},
-] );
-```
+_The PHP implementation of block context is currently experimental and subject to breaking changes. It will be documented in the future once the API has stabilized._

lib/class-wp-block.php

@@ -156,7 +156,7 @@ function( $inner_block ) use ( $child_context, $registry ) {
 	 * @return string Rendered block output.
 	 */
 	public function render() {
-		global $post, $block;
+		global $post, $_experimental_block;
 
 		$is_dynamic    = $this->name && null !== $this->block_type && $this->block_type->is_dynamic();
 		$block_content = '';
@@ -169,12 +169,12 @@ public function render() {
 		}
 
 		if ( $is_dynamic ) {
-			$global_post   = $post;
-			$global_block  = $block;
-			$block         = $this;
-			$block_content = (string) call_user_func( $this->block_type->render_callback, $this->attributes, $block_content );
-			$block         = $global_block;
-			$post          = $global_post;
+			$global_post         = $post;
+			$global_block        = $_experimental_block;
+			$_experimental_block = $this;
+			$block_content       = (string) call_user_func( $this->block_type->render_callback, $this->attributes, $block_content );
+			$_experimental_block = $global_block;
+			$post                = $global_post;
 		}
 
 		return $block_content;

packages/block-library/src/post-title/index.php

@@ -11,12 +11,12 @@
  * @return string Returns the filtered post title for the current post wrapped inside "h1" tags.
  */
 function render_block_core_post_title() {
-	global $block;
-	if ( ! isset( $block->context['postId'] ) ) {
+	global $_experimental_block;
+	if ( ! isset( $_experimental_block->context['postId'] ) ) {
 		return '';
 	}
 
-	return '<h1>' . get_the_title( $block->context['postId'] ) . '</h1>';
+	return '<h1>' . get_the_title( $_experimental_block->context['postId'] ) . '</h1>';
 }
 
 /**

packages/e2e-tests/plugins/block-context.php

@@ -49,9 +49,9 @@ function gutenberg_test_register_context_blocks() {
 		array(
 			'context'         => array( 'gutenberg/recordId' ),
 			'render_callback' => function() {
-				global $block;
+				global $_experimental_block;
 
-				$record_id = $block->context['gutenberg/recordId'];
+				$record_id = $_experimental_block->context['gutenberg/recordId'];
 
 				if ( ! is_int( $record_id ) ) {
 					throw new Exception( 'Expected numeric recordId' );

phpunit/class-block-context-test.php

@@ -105,9 +105,9 @@ function test_provides_block_context() {
 					'gutenberg/contextWithoutDefault',
 				),
 				'render_callback' => function() use ( &$provided_context ) {
-					global $block;
+					global $_experimental_block;
 
-					$provided_context[] = $block->context;
+					$provided_context[] = $_experimental_block->context;
 
 					return '';
 				},

phpunit/class-wp-block-test.php

@@ -260,12 +260,12 @@ function test_render_assigns_instance_global_for_render_callback() {
 					),
 				),
 				'render_callback' => function() {
-					global $block;
+					global $_experimental_block;
 
 					return sprintf(
 						'Hello %s%s',
-						$block->attributes['toWhom'],
-						$block->attributes['punctuation']
+						$_experimental_block->attributes['toWhom'],
+						$_experimental_block->attributes['punctuation']
 					);
 				},
 			)