Add compat layer

lib/compat/wordpress-6.7/blocks.php

@@ -0,0 +1,45 @@
+<?php
+/**
+ * Temporary compatibility shims for block APIs present in Gutenberg.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Allow passing a PHP file as `variations` field for Core versions < 6.7
+ *
+ * @param array $settings Array of determined settings for registering a block type.
+ * @param array $metadata Metadata provided for registering a block type.
+ * @return array The block type settings
+ */
+function gutenberg_filter_block_type_metadata_settings_allow_variations_php_file( $settings, $metadata ) {
+	// If `variations` is a string, it's the name of a PHP file that
+	// generates the variations.
+	if ( ! empty( $settings['variations'] ) && is_string( $settings['variations'] ) ) {
+		$variations_path = wp_normalize_path(
+			realpath(
+				dirname( $metadata['file'] ) . '/' .
+				remove_block_asset_path_prefix( $metadata['variations'] )
+			)
+		);
+		if ( $variations_path ) {
+			/**
+			 * Generates the list of block variations.
+			 *
+			 * @since 6.7.0
+			 *
+			 * @return string Returns the list of block variations.
+			 */
+			$settings['variation_callback'] = static function () use ( $variations_path ) {
+				$variations = require $variations_path;
+				return $variations;
+			};
+			// The block instance's `variations` field is only allowed to be an array
+			// (of known block variations). We unset it so that the block instance will
+			// provide a getter that returns the result of the `variation_callback` instead.
+			unset( $settings['variations'] );
+		}
+	}
+	return $settings;
+}
+add_filter( 'block_type_metadata_settings', 'gutenberg_filter_block_type_metadata_settings_allow_variations_php_file', 10, 2 );