first commit

wp-includes/block-supports/block-visibility.php

@@ -0,0 +1,33 @@
+<?php
+/**
+ * Block visibility block support flag.
+ *
+ * @package WordPress
+ * @since 6.9.0
+ */
+
+/**
+ * Render nothing if the block is hidden.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @param string $block_content Rendered block content.
+ * @param array  $block         Block object.
+ * @return string Filtered block content.
+ */
+function wp_render_block_visibility_support( $block_content, $block ) {
+	$block_type = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );
+
+	if ( ! $block_type || ! block_has_support( $block_type, 'visibility', true ) ) {
+		return $block_content;
+	}
+
+	if ( isset( $block['attrs']['metadata']['blockVisibility'] ) && false === $block['attrs']['metadata']['blockVisibility'] ) {
+		return '';
+	}
+
+	return $block_content;
+}
+
+add_filter( 'render_block', 'wp_render_block_visibility_support', 10, 2 );