diff -r 34716fd837a4 -r be944660c56a wp/wp-includes/block-template-utils.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/block-template-utils.php	Wed Sep 21 18:19:35 2022 +0200
@@ -0,0 +1,143 @@
+<?php
+/**
+ * Utilities used to fetch and create templates.
+ *
+ * @package WordPress
+ * @since 5.8.0
+ */
+
+/**
+ * Build a unified template object based a post Object.
+ *
+ * @access private
+ * @since 5.8.0
+ *
+ * @param WP_Post $post Template post.
+ *
+ * @return WP_Block_Template|WP_Error Template.
+ */
+function _build_template_result_from_post( $post ) {
+	$terms = get_the_terms( $post, 'wp_theme' );
+
+	if ( is_wp_error( $terms ) ) {
+		return $terms;
+	}
+
+	if ( ! $terms ) {
+		return new WP_Error( 'template_missing_theme', __( 'No theme is defined for this template.' ) );
+	}
+
+	$theme = $terms[0]->name;
+
+	$template                 = new WP_Block_Template();
+	$template->wp_id          = $post->ID;
+	$template->id             = $theme . '//' . $post->post_name;
+	$template->theme          = $theme;
+	$template->content        = $post->post_content;
+	$template->slug           = $post->post_name;
+	$template->source         = 'custom';
+	$template->type           = $post->post_type;
+	$template->description    = $post->post_excerpt;
+	$template->title          = $post->post_title;
+	$template->status         = $post->post_status;
+	$template->has_theme_file = false;
+
+	return $template;
+}
+
+/**
+ * Retrieves a list of unified template objects based on a query.
+ *
+ * @since 5.8.0
+ *
+ * @param array $query {
+ *     Optional. Arguments to retrieve templates.
+ *
+ *     @type array  $slug__in List of slugs to include.
+ *     @type int    $wp_id Post ID of customized template.
+ * }
+ * @param string $template_type Optional. The template type (post type). Default 'wp_template'.
+ * @return WP_Block_Template[] Block template objects.
+ */
+function get_block_templates( $query = array(), $template_type = 'wp_template' ) {
+	$wp_query_args = array(
+		'post_status'    => array( 'auto-draft', 'draft', 'publish' ),
+		'post_type'      => $template_type,
+		'posts_per_page' => -1,
+		'no_found_rows'  => true,
+		'tax_query'      => array(
+			array(
+				'taxonomy' => 'wp_theme',
+				'field'    => 'name',
+				'terms'    => wp_get_theme()->get_stylesheet(),
+			),
+		),
+	);
+
+	if ( isset( $query['slug__in'] ) ) {
+		$wp_query_args['post_name__in'] = $query['slug__in'];
+	}
+
+	// This is only needed for the regular templates CPT listing and editor.
+	if ( isset( $query['wp_id'] ) ) {
+		$wp_query_args['p'] = $query['wp_id'];
+	} else {
+		$wp_query_args['post_status'] = 'publish';
+	}
+
+	$template_query = new WP_Query( $wp_query_args );
+	$query_result   = array();
+	foreach ( $template_query->posts as $post ) {
+		$template = _build_template_result_from_post( $post );
+
+		if ( ! is_wp_error( $template ) ) {
+			$query_result[] = $template;
+		}
+	}
+
+	return $query_result;
+}
+
+/**
+ * Retrieves a single unified template object using its id.
+ *
+ * @since 5.8.0
+ *
+ * @param string $id Template unique identifier (example: theme_slug//template_slug).
+ * @param string $template_type wp_template.
+ *
+ * @return WP_Block_Template|null Template.
+ */
+function get_block_template( $id, $template_type = 'wp_template' ) {
+	$parts = explode( '//', $id, 2 );
+	if ( count( $parts ) < 2 ) {
+		return null;
+	}
+	list( $theme, $slug ) = $parts;
+	$wp_query_args        = array(
+		'post_name__in'  => array( $slug ),
+		'post_type'      => $template_type,
+		'post_status'    => array( 'auto-draft', 'draft', 'publish', 'trash' ),
+		'posts_per_page' => 1,
+		'no_found_rows'  => true,
+		'tax_query'      => array(
+			array(
+				'taxonomy' => 'wp_theme',
+				'field'    => 'name',
+				'terms'    => $theme,
+			),
+		),
+	);
+	$template_query       = new WP_Query( $wp_query_args );
+	$posts                = $template_query->posts;
+
+	if ( count( $posts ) > 0 ) {
+		$template = _build_template_result_from_post( $posts[0] );
+
+		if ( ! is_wp_error( $template ) ) {
+			return $template;
+		}
+	}
+
+	return null;
+}