diff --git a/src/wp-includes/blocks.php b/src/wp-includes/blocks.php
index fdd9de9aff..efdd9b1b1a 100644
--- a/src/wp-includes/blocks.php
+++ b/src/wp-includes/blocks.php
@@ -1518,6 +1518,83 @@ function traverse_and_serialize_block( $block, $pre_callback = null, $post_callb
);
}
+/**
+ * Replaces patterns in a block tree with their content.
+ *
+ * @since 6.6.0
+ *
+ * @param array $blocks An array blocks.
+ *
+ * @return array An array of blocks with patterns replaced by their content.
+ */
+function resolve_pattern_blocks( $blocks ) {
+ static $inner_content;
+ // Keep track of seen references to avoid infinite loops.
+ static $seen_refs = array();
+ $i = 0;
+ while ( $i < count( $blocks ) ) {
+ if ( 'core/pattern' === $blocks[ $i ]['blockName'] ) {
+ $attrs = $blocks[ $i ]['attrs'];
+
+ if ( empty( $attrs['slug'] ) ) {
+ ++$i;
+ continue;
+ }
+
+ $slug = $attrs['slug'];
+
+ if ( isset( $seen_refs[ $slug ] ) ) {
+ // Skip recursive patterns.
+ array_splice( $blocks, $i, 1 );
+ continue;
+ }
+
+ $registry = WP_Block_Patterns_Registry::get_instance();
+ $pattern = $registry->get_registered( $slug );
+
+ // Skip unknown patterns.
+ if ( ! $pattern ) {
+ ++$i;
+ continue;
+ }
+
+ $blocks_to_insert = parse_blocks( $pattern['content'] );
+ $seen_refs[ $slug ] = true;
+ $prev_inner_content = $inner_content;
+ $inner_content = null;
+ $blocks_to_insert = resolve_pattern_blocks( $blocks_to_insert );
+ $inner_content = $prev_inner_content;
+ unset( $seen_refs[ $slug ] );
+ array_splice( $blocks, $i, 1, $blocks_to_insert );
+
+ // If we have inner content, we need to insert nulls in the
+ // inner content array, otherwise serialize_blocks will skip
+ // blocks.
+ if ( $inner_content ) {
+ $null_indices = array_keys( $inner_content, null, true );
+ $content_index = $null_indices[ $i ];
+ $nulls = array_fill( 0, count( $blocks_to_insert ), null );
+ array_splice( $inner_content, $content_index, 1, $nulls );
+ }
+
+ // Skip inserted blocks.
+ $i += count( $blocks_to_insert );
+ } else {
+ if ( ! empty( $blocks[ $i ]['innerBlocks'] ) ) {
+ $prev_inner_content = $inner_content;
+ $inner_content = $blocks[ $i ]['innerContent'];
+ $blocks[ $i ]['innerBlocks'] = resolve_pattern_blocks(
+ $blocks[ $i ]['innerBlocks']
+ );
+ $blocks[ $i ]['innerContent'] = $inner_content;
+ $inner_content = $prev_inner_content;
+ }
+ ++$i;
+ }
+ }
+ return $blocks;
+}
+
/**
* Given an array of parsed block trees, applies callbacks before and after serializing them and
* returns their concatenated output.
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-block-patterns-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-patterns-controller.php
index d8f083924e..c98b2a7c57 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-block-patterns-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-patterns-controller.php
@@ -162,6 +162,12 @@ class WP_REST_Block_Patterns_Controller extends WP_REST_Controller {
* @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
*/
public function prepare_item_for_response( $item, $request ) {
+ // Resolve pattern blocks so they don't need to be resolved client-side
+ // in the editor, improving performance.
+ $blocks = parse_blocks( $item['content'] );
+ $blocks = resolve_pattern_blocks( $blocks );
+ $item['content'] = serialize_blocks( $blocks );
+
$fields = $this->get_fields_for_response( $request );
$keys = array(
'name' => 'name',
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php
index 0ac6c7de5a..cbf0ee040a 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php
@@ -668,6 +668,12 @@ class WP_REST_Templates_Controller extends WP_REST_Controller {
* @return WP_REST_Response Response object.
*/
public function prepare_item_for_response( $item, $request ) {
+ // Resolve pattern blocks so they don't need to be resolved client-side
+ // in the editor, improving performance.
+ $blocks = parse_blocks( $item->content );
+ $blocks = resolve_pattern_blocks( $blocks );
+ $item->content = serialize_blocks( $blocks );
+
// Restores the more descriptive, specific name for use within this method.
$template = $item;
diff --git a/tests/phpunit/tests/blocks/resolvePatternBlocks.php b/tests/phpunit/tests/blocks/resolvePatternBlocks.php
new file mode 100644
index 0000000000..b2e6fa6463
--- /dev/null
+++ b/tests/phpunit/tests/blocks/resolvePatternBlocks.php
@@ -0,0 +1,72 @@
+<?php
+/**
+ * Tests for resolve_pattern_blocks.
+ *
+ * @package WordPress
+ * @subpackage Blocks
+ *
+ * @since 6.6.0
+ *
+ * @group blocks
+ * @covers resolve_pattern_blocks
+ */
+class Tests_Blocks_ResolvePatternBlocks extends WP_UnitTestCase {
+ public function set_up() {
+ parent::set_up();
+
+ register_block_pattern(
+ 'core/test',
+ array(
+ 'title' => 'Test',
+ 'content' => '<!-- wp:paragraph -->Hello<!-- /wp:paragraph --><!-- wp:paragraph -->World<!-- /wp:paragraph -->',
+ 'description' => 'Test pattern.',
+ )
+ );
+ register_block_pattern(
+ 'core/recursive',
+ array(
+ 'title' => 'Recursive',
+ 'content' => '<!-- wp:paragraph -->Recursive<!-- /wp:paragraph --><!-- wp:pattern {"slug":"core/recursive"} /-->',
+ 'description' => 'Recursive pattern.',
+ )
+ );
+ }
+
+ public function tear_down() {
+ unregister_block_pattern( 'core/test' );
+ unregister_block_pattern( 'core/recursive' );
+
+ parent::tear_down();
+ }
+
+ /**
+ * @dataProvider data_should_resolve_pattern_blocks_as_expected
+ *
+ * @ticket 61228
+ *
+ * @param string $blocks A string representing blocks that need resolving.
+ * @param string $expected Expected result.
+ */
+ public function test_should_resolve_pattern_blocks_as_expected( $blocks, $expected ) {
+ $actual = resolve_pattern_blocks( parse_blocks( $blocks ) );
+ $this->assertSame( $expected, serialize_blocks( $actual ) );
+ }
+
+ /**
+ * Data provider.
+ *
+ * @return array
+ */
+ public function data_should_resolve_pattern_blocks_as_expected() {
+ return array(
+ // Works without attributes, leaves the block as is.
+ 'pattern with no slug attribute' => array( '<!-- wp:pattern /-->', '<!-- wp:pattern /-->' ),
+ // Resolves the pattern.
+ 'test pattern' => array( '<!-- wp:pattern {"slug":"core/test"} /-->', '<!-- wp:paragraph -->Hello<!-- /wp:paragraph --><!-- wp:paragraph -->World<!-- /wp:paragraph -->' ),
+ // Skips recursive patterns.
+ 'recursive pattern' => array( '<!-- wp:pattern {"slug":"core/recursive"} /-->', '<!-- wp:paragraph -->Recursive<!-- /wp:paragraph -->' ),
+ // Resolves the pattern within a block.
+ 'pattern within a block' => array( '<!-- wp:group --><!-- wp:paragraph -->Before<!-- /wp:paragraph --><!-- wp:pattern {"slug":"core/test"} /--><!-- wp:paragraph -->After<!-- /wp:paragraph --><!-- /wp:group -->', '<!-- wp:group --><!-- wp:paragraph -->Before<!-- /wp:paragraph --><!-- wp:paragraph -->Hello<!-- /wp:paragraph --><!-- wp:paragraph -->World<!-- /wp:paragraph --><!-- wp:paragraph -->After<!-- /wp:paragraph --><!-- /wp:group -->' ),
+ );
+ }
+}