From 1fcbffcaa1ba4d3a048da84252fe0d0e952712db Mon Sep 17 00:00:00 2001
From: Marcus Kazmierczak <marcus@mkaz.com>
Date: Tue, 4 May 2021 10:16:10 -0700
Subject: [PATCH] Allow Page List to only show children

- Add a childrenOnly attribute to Edit
- Update render to use attribute and only pull in children

Fixes #31063

?? This uses global $post which is probably not ideal
---
 .../block-library/src/page-list/block.json    |  5 ++++
 packages/block-library/src/page-list/edit.js  | 25 +++++++++++++++++--
 .../block-library/src/page-list/index.php     | 22 +++++++++++-----
 3 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/packages/block-library/src/page-list/block.json b/packages/block-library/src/page-list/block.json
index 25118d2dbeffb4..28515395b64292 100644
--- a/packages/block-library/src/page-list/block.json
+++ b/packages/block-library/src/page-list/block.json
@@ -16,6 +16,11 @@
 		"showSubmenuIcon",
 		"style"
 	],
+	"attributes": {
+		"childrenOnly": {
+			"type": "boolean"
+		}
+	},
 	"supports": {
 		"reusable": false,
 		"html": false
diff --git a/packages/block-library/src/page-list/edit.js b/packages/block-library/src/page-list/edit.js
index 4274b3d2d5b1e6..00949e7eb6da22 100644
--- a/packages/block-library/src/page-list/edit.js
+++ b/packages/block-library/src/page-list/edit.js
@@ -10,9 +10,10 @@ import {
 	BlockControls,
 	useBlockProps,
 	store as blockEditorStore,
+	InspectorControls,
 } from '@wordpress/block-editor';
 import ServerSideRender from '@wordpress/server-side-render';
-import { ToolbarButton } from '@wordpress/components';
+import { PanelBody, ToggleControl, ToolbarButton } from '@wordpress/components';
 import { __ } from '@wordpress/i18n';
 import { useEffect, useState } from '@wordpress/element';
 import { useSelect } from '@wordpress/data';
@@ -28,7 +29,12 @@ import ConvertToLinksModal from './convert-to-links-modal';
 // Performance of Navigation Links is not good past this value.
 const MAX_PAGE_COUNT = 100;
 
-export default function PageListEdit( { context, clientId } ) {
+export default function PageListEdit( {
+	attributes,
+	context,
+	clientId,
+	setAttributes,
+} ) {
 	const { textColor, backgroundColor, showSubmenuIcon, style } =
 		context || {};
 
@@ -78,8 +84,23 @@ export default function PageListEdit( { context, clientId } ) {
 	const openModal = () => setOpen( true );
 	const closeModal = () => setOpen( false );
 
+	const { childrenOnly } = attributes;
+
 	return (
 		<>
+			<InspectorControls>
+				<PanelBody>
+					<ToggleControl
+						label={ __( 'Show only children' ) }
+						checked={ childrenOnly }
+						onChange={ () => {
+							setAttributes( {
+								childrenOnly: ! childrenOnly,
+							} );
+						} }
+					/>
+				</PanelBody>
+			</InspectorControls>
 			{ allowConvertToLinks && (
 				<BlockControls group="other">
 					<ToolbarButton title={ __( 'Edit' ) } onClick={ openModal }>
diff --git a/packages/block-library/src/page-list/index.php b/packages/block-library/src/page-list/index.php
index a0cadde487d571..cc8c165d5681a6 100644
--- a/packages/block-library/src/page-list/index.php
+++ b/packages/block-library/src/page-list/index.php
@@ -146,27 +146,37 @@ function nest_pages( $current_level, $children ) {
  * @return string Returns the page list markup.
  */
 function render_block_core_page_list( $attributes, $content, $block ) {
+	global $post; // ??
 	static $block_id = 0;
 	$block_id++;
 
+
+	$childrenOnly = ( isset( $attributes['childrenOnly'] ) && $attributes['childrenOnly'] );
+	$parent_id = ( $post->post_parent ) ? $post->post_parent : $post->ID;
+
 	// TODO: When https://core.trac.wordpress.org/ticket/39037 REST API support for multiple orderby values is resolved,
 	// update 'sort_column' to 'menu_order, post_title'. Sorting by both menu_order and post_title ensures a stable sort.
 	// Otherwise with pages that have the same menu_order value, we can see different ordering depending on how DB
 	// queries are constructed internally. For example we might see a different order when a limit is set to <499
 	// versus >= 500.
-	$all_pages = get_pages(
-		array(
-			'sort_column' => 'menu_order',
-			'order'       => 'asc',
-		)
+	$query_args = array(
+		'sort_column' => 'menu_order',
+		'order'       => 'asc',
 	);
 
+	if ( $childrenOnly ) {
+		$query_args['child_of'] = $parent_id;
+	}
+
+	$all_pages = get_pages( $query_args );
+
 	$top_level_pages = array();
 
 	$pages_with_children = array();
 
 	foreach ( (array) $all_pages as $page ) {
-		if ( $page->post_parent ) {
+		if ( ( $page->post_parent && !$childrenOnly ) ||
+			( $childrenOnly && $page->post_parent !== $parent_id ) ) {
 			$pages_with_children[ $page->post_parent ][ $page->ID ] = array(
 				'title' => $page->post_title,
 				'link'  => get_permalink( $page->ID ),