com_installer warnings empty state (#33411)

Author: Phil E. Taylor

administrator/components/com_installer/src/View/Warnings/HtmlView.php

@@ -32,8 +32,13 @@ class HtmlView extends InstallerViewDefault
 	 */
 	public function display($tpl = null)
 	{
-		$items = $this->get('Items');
-		$this->messages = &$items;
+		$this->messages = $this->get('Items');
+
+		if (!\count($this->messages))
+		{
+			$this->setLayout('emptystate');
+		}
+
 		parent::display($tpl);
 	}
 

administrator/components/com_installer/tmpl/warnings/emptystate.php

@@ -0,0 +1,22 @@
+<?php
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_installer
+ *
+ * @copyright   (C) 2021 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+defined('_JEXEC') or die;
+
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Layout\LayoutHelper;
+
+$displayData = [
+	'helpURL'    => 'https://docs.joomla.org/Help4.x:Information:_Warnings',
+	'icon'       => 'icon-puzzle-piece install',
+	'title'      => Text::_('COM_INSTALLER_MSG_WARNINGS_NONE'),
+	'content'    => '',
+];
+
+echo LayoutHelper::render('joomla.content.emptystate', $displayData);

administrator/language/en-GB/com_installer.ini

@@ -171,7 +171,7 @@ COM_INSTALLER_MSG_UPDATESITES_REBUILD_SUCCESS="Update sites have been rebuilt fr
 COM_INSTALLER_MSG_UPDATESITES_REBUILD_WARNING="Update sites have been rebuilt. No extension with updates sites discovered."
 COM_INSTALLER_MSG_WARNING_NO_LANGUAGES_UPDATESERVER="The update table is not up to date. Please <a href=\"index.php?option=com_installer&view=updatesites\">rebuild your update server table</a>"
 COM_INSTALLER_MSG_WARNINGFURTHERINFO="Further information on warnings"
-COM_INSTALLER_MSG_WARNINGFURTHERINFODESC="For more information see the <a href=\"https://docs.joomla.org\" target=\"_blank\" class=\"alert-link\">Joomla! Documentation Site</a>."
+COM_INSTALLER_MSG_WARNINGFURTHERINFODESC="For more information see the <a href=\"https://docs.joomla.org/Help4.x:Information:_Warnings\" target=\"_blank\" class=\"alert-link\">Joomla! Documentation Site</a>."
 COM_INSTALLER_MSG_WARNINGS_FILEUPLOADISDISABLEDDESC="File uploads are required to upload extensions with the installer."
 COM_INSTALLER_MSG_WARNINGS_FILEUPLOADSDISABLED="File uploads disabled."
 COM_INSTALLER_MSG_WARNINGS_JOOMLATMPNOTSET="The Joomla temporary folder is not set."