Call variation through callback so it's only loaded when needed - in …

…support of trac 59969 (#56952)

* call variation through callback so it's only loaded when needed.

* move gutenberg_add_hooked_blocks from 6.4 to 6.5

* cs fixes

* fix version number

* revert some code

* adapting to variation_calback

* B/C for plugin

* cs fixes

* cs fixes

* cs fixes

* shims to support block variation changes for WP < 6.5

* EOL for PHPCS

lib/compat/wordpress-6.5/blocks.php

@@ -0,0 +1,24 @@
+<?php
+/**
+ * Temporary compatibility shims for block APIs present in Gutenberg.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Shim for the `variation_callback` block type argument.
+ *
+ * @param array $args The block type arguments.
+ * @return array The updated block type arguments.
+ */
+function gutenberg_register_block_type_args_shim( $args ) {
+	if ( isset( $args['variation_callback'] ) && is_callable( $args['variation_callback'] ) ) {
+		$args['variations'] = call_user_func( $args['variation_callback'] );
+		unset( $args['variation_callback'] );
+	}
+	return $args;
+}
+
+if ( ! method_exists( 'WP_Block_Type', 'get_variations' ) ) {
+	add_filter( 'register_block_type_args', 'gutenberg_register_block_type_args_shim' );
+}

lib/load.php

@@ -101,6 +101,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 require __DIR__ . '/compat/wordpress-6.4/kses.php';
 
 // WordPress 6.5 compat.
+require __DIR__ . '/compat/wordpress-6.5/blocks.php';
 require __DIR__ . '/compat/wordpress-6.5/block-patterns.php';
 require __DIR__ . '/compat/wordpress-6.5/class-wp-navigation-block-renderer.php';
 require __DIR__ . '/compat/wordpress-6.5/kses.php';

packages/block-library/src/navigation-link/index.php

@@ -368,11 +368,11 @@ function block_core_navigation_link_unregister_variation( $name ) {
 
 /**
  * Register the navigation link block.
+ * Returns an array of variations for the navigation link block.
  *
- * @uses render_block_core_navigation()
- * @throws WP_Error An WP_Error exception parsing the block definition.
+ * @return array
  */
-function register_block_core_navigation_link() {
+function build_navigation_link_block_variations() {
 	// This will only handle post types and taxonomies registered until this point (init on priority 9).
 	// See action hooks below for other post types and taxonomies.
 	// See https://github.com/WordPress/gutenberg/issues/53826 for details.
@@ -407,11 +407,21 @@ function register_block_core_navigation_link() {
 		}
 	}
 
+	return array_merge( $built_ins, $variations );
+}
+
+/**
+ * Register the navigation link block.
+ *
+ * @uses render_block_core_navigation()
+ * @throws WP_Error An WP_Error exception parsing the block definition.
+ */
+function register_block_core_navigation_link() {
 	register_block_type_from_metadata(
 		__DIR__ . '/navigation-link',
 		array(
-			'render_callback' => 'render_block_core_navigation_link',
-			'variations'      => array_merge( $built_ins, $variations ),
+			'render_callback'    => 'render_block_core_navigation_link',
+			'variation_callback' => 'build_navigation_link_block_variations',
 		)
 	);
 }

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

@@ -59,9 +59,11 @@ function render_block_core_post_terms( $attributes, $content, $block ) {
 }
 
 /**
- * Registers the `core/post-terms` block on the server.
+ * Returns the available variations for the `core/post-terms` block.
+ *
+ * @return array The available variations for the block.
  */
-function register_block_core_post_terms() {
+function build_post_term_block_variations() {
 	$taxonomies = get_taxonomies(
 		array(
 			'publicly_queryable' => true,
@@ -103,11 +105,18 @@ function register_block_core_post_terms() {
 		}
 	}
 
+	return array_merge( $built_ins, $custom_variations );
+}
+
+/**
+ * Registers the `core/post-terms` block on the server.
+ */
+function register_block_core_post_terms() {
 	register_block_type_from_metadata(
 		__DIR__ . '/post-terms',
 		array(
-			'render_callback' => 'render_block_core_post_terms',
-			'variations'      => array_merge( $built_ins, $custom_variations ),
+			'render_callback'    => 'render_block_core_post_terms',
+			'variation_callback' => 'build_post_term_block_variations',
 		)
 	);
 }

packages/block-library/src/template-part/index.php

@@ -281,8 +281,8 @@ function register_block_core_template_part() {
 	register_block_type_from_metadata(
 		__DIR__ . '/template-part',
 		array(
-			'render_callback' => 'render_block_core_template_part',
-			'variations'      => build_template_part_block_variations(),
+			'render_callback'    => 'render_block_core_template_part',
+			'variation_callback' => 'build_template_part_block_variations',
 		)
 	);
 }

phpcs.xml.dist

@@ -115,6 +115,8 @@
 				<element value="apply_block_core_search_border_style"/>
 				<element value="apply_block_core_search_border_styles"/>
 				<element value="build_dropdown_script_block_core_categories"/>
+				<element value="build_navigation_link_block_variations"/>
+				<element value="build_post_term_block_variations"/>
 				<element value="build_template_part_block_area_variations"/>
 				<element value="build_template_part_block_instance_variations"/>
 				<element value="build_template_part_block_variations"/>