primo commit

administrator/components/com_joomlaupdate/config.xml

@@ -0,0 +1,75 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<config>
+	<help key="Joomla_Update:_Options"/>
+	<inlinehelp button="show"/>
+	<fieldset
+		name="sources"
+		label="COM_JOOMLAUPDATE_CONFIG_SOURCES_LABEL"
+		description="COM_JOOMLAUPDATE_CONFIG_SOURCES_DESC"
+		>
+
+		<field
+			name="updatesource"
+			type="list"
+			label="COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_LABEL"
+			default="default"
+			validate="options"
+			>
+			<!-- Note: Changed the values lts to default and sts to next with 3.4.0 -->
+			<!--       All invalid/unsupported/obsolete options equated to default in code with 3.4.0 -->
+			<option value="default">COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_DEFAULT</option>
+			<option value="next">COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_NEXT</option>
+			<option value="custom">COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_CUSTOM</option>
+		</field>
+
+		<field
+			name="minimum_stability"
+			type="list"
+			label="COM_JOOMLAUPDATE_MINIMUM_STABILITY_LABEL"
+			description="COM_JOOMLAUPDATE_MINIMUM_STABILITY_DESC"
+			default="4"
+			validate="options"
+			>
+			<option value="0">COM_JOOMLAUPDATE_MINIMUM_STABILITY_DEV</option>
+			<option value="1">COM_JOOMLAUPDATE_MINIMUM_STABILITY_ALPHA</option>
+			<option value="2">COM_JOOMLAUPDATE_MINIMUM_STABILITY_BETA</option>
+			<option value="3">COM_JOOMLAUPDATE_MINIMUM_STABILITY_RC</option>
+			<option value="4">COM_JOOMLAUPDATE_MINIMUM_STABILITY_STABLE</option>
+		</field>
+
+		<field
+			name="customurl"
+			type="url"
+			label="COM_JOOMLAUPDATE_CONFIG_CUSTOMURL_LABEL"
+			default=""
+			length="50"
+			showon="updatesource:custom"
+			validate="url"
+		/>
+
+		<field
+			name="versioncheck"
+			type="radio"
+			label="COM_JOOMLAUPDATE_CONFIG_VERSIONCHECK_LABEL"
+			description="COM_JOOMLAUPDATE_CONFIG_VERSIONCHECK_DESC"
+			layout="joomla.form.field.radio.switcher"
+			default="1"
+			>
+			<option value="0">JHIDE</option>
+			<option value="1">JSHOW</option>
+		</field>
+
+		<field
+			name="backupcheck"
+			type="radio"
+			label="COM_JOOMLAUPDATE_CONFIG_BACKUPCHECK_LABEL"
+			description="COM_JOOMLAUPDATE_CONFIG_BACKUPCHECK_DESC"
+			layout="joomla.form.field.radio.switcher"
+			default="1"
+			>
+			<option value="0">JHIDE</option>
+			<option value="1">JSHOW</option>
+		</field>
+
+	</fieldset>
+</config>

administrator/components/com_joomlaupdate/finalisation.php

@@ -0,0 +1,275 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2016 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ *
+ * Important Notes:
+ * - Unlike other files, this file requires multiple namespace declarations in order to overload core classes during the update process
+ * - Also unlike other files, the normal constant defined checks must be within the global namespace declaration and can't be outside of it
+ */
+
+namespace {
+
+    // Require the restoration environment or fail cold. Prevents direct web access.
+    \defined('_JOOMLA_UPDATE') or die();
+
+    // Fake a miniature Joomla environment
+    if (!\defined('_JEXEC')) {
+        \define('_JEXEC', 1);
+    }
+
+    if (!\function_exists('jimport')) {
+        /**
+         * This is deprecated but it may still be used in the update finalisation script.
+         *
+         * @param   string  $path  Ignored.
+         * @param   string  $base  Ignored.
+         *
+         * @return  boolean  Always true.
+         *
+         * @since   1.7.0
+         */
+        function jimport(string $path, ?string $base = null): bool
+        {
+            // Do nothing
+            return true;
+        }
+    }
+
+    if (!\function_exists('finalizeUpdate')) {
+        /**
+         * Run part of the Joomla! finalisation script, namely the part that cleans up unused files/folders
+         *
+         * @param   string  $siteRoot     The root to the Joomla! site
+         * @param   string  $restorePath  The base path to extract.php
+         *
+         * @return  void
+         *
+         * @since   3.5.1
+         */
+        function finalizeUpdate(string $siteRoot, string $restorePath): void
+        {
+            if (!\defined('JPATH_ROOT')) {
+                \define('JPATH_ROOT', $siteRoot);
+            }
+
+            $filePath = JPATH_ROOT . '/administrator/components/com_admin/script.php';
+
+            if (file_exists($filePath)) {
+                require_once $filePath;
+            }
+
+            // Make sure Joomla!'s code can figure out which files exist and need be removed
+            clearstatcache();
+
+            // Remove obsolete files - prevents errors occurring in some system plugins
+            if (class_exists('JoomlaInstallerScript')) {
+                (new JoomlaInstallerScript())->deleteUnexistingFiles();
+            }
+
+            /**
+             * Remove autoload_psr4.php so that namespace map is re-generated on the next request. This is needed
+             * when there are new classes added to extensions on new Joomla! release.
+             */
+            $namespaceMapFile = JPATH_ROOT . '/administrator/cache/autoload_psr4.php';
+
+            if (is_file($namespaceMapFile)) {
+                \Joomla\Filesystem\File::delete($namespaceMapFile);
+            }
+        }
+    }
+}
+
+namespace Joomla\Filesystem
+{
+    // Fake the File class
+    if (!class_exists('\Joomla\Filesystem\File')) {
+        /**
+         * File mock class
+         *
+         * @since  3.5.1
+         */
+        abstract class File
+        {
+            /**
+             * Proxies checking a file exists to the native php version
+             *
+             * @param   string  $fileName  The path to the file to be checked
+             *
+             * @return  boolean
+             *
+             * @since   3.5.1
+             */
+            public static function exists(string $fileName): bool
+            {
+                return @file_exists($fileName);
+            }
+
+            /**
+             * Delete a file and invalidate the PHP OPcache
+             *
+             * @param   string  $fileName  The path to the file to be deleted
+             *
+             * @return  boolean
+             *
+             * @since   3.5.1
+             */
+            public static function delete(string $fileName): bool
+            {
+                self::invalidateFileCache($fileName);
+
+                return @unlink($fileName);
+            }
+
+            /**
+             * Rename a file and invalidate the PHP OPcache
+             *
+             * @param   string  $src   The path to the source file
+             * @param   string  $dest  The path to the destination file
+             *
+             * @return  boolean  True on success
+             *
+             * @since   4.0.1
+             */
+            public static function move(string $src, string $dest): bool
+            {
+                self::invalidateFileCache($src);
+
+                $result = @rename($src, $dest);
+
+                if ($result) {
+                    self::invalidateFileCache($dest);
+                }
+
+                return $result;
+            }
+
+            /**
+             * Invalidate opcache for a newly written/deleted file immediately, if opcache* functions exist and if this was a PHP file.
+             *
+             * @param   string  $filepath   The path to the file just written to, to flush from opcache
+             * @param   boolean $force      If set to true, the script will be invalidated regardless of whether invalidation is necessary
+             *
+             * @return  boolean TRUE if the opcode cache for script was invalidated/nothing to invalidate,
+             *                  or FALSE if the opcode cache is disabled or other conditions returning
+             *                  FALSE from opcache_invalidate (like file not found).
+             *
+             * @since  4.0.2
+             */
+            public static function invalidateFileCache($filepath, $force = true)
+            {
+                return clearFileInOPCache($filepath);
+            }
+        }
+    }
+
+    // Fake the Folder class, mapping it to Restore's post-processing class
+    if (!class_exists('\Joomla\Filesystem\Folder')) {
+        /**
+         * Folder mock class
+         *
+         * @since  3.5.1
+         */
+        abstract class Folder
+        {
+            /**
+             * Proxies checking a folder exists to the native php version
+             *
+             * @param   string  $folderName  The path to the folder to be checked
+             *
+             * @return  boolean
+             *
+             * @since   3.5.1
+             */
+            public static function exists(string $folderName): bool
+            {
+                return @is_dir($folderName);
+            }
+
+            /**
+             * Delete a folder recursively and invalidate the PHP OPcache
+             *
+             * @param   string  $folderName  The path to the folder to be deleted
+             *
+             * @return  boolean
+             *
+             * @since   3.5.1
+             */
+            public static function delete(string $folderName): bool
+            {
+                if (substr($folderName, -1) == '/') {
+                    $folderName = substr($folderName, 0, -1);
+                }
+
+                if (!@file_exists($folderName) || !@is_dir($folderName) || !is_readable($folderName)) {
+                    return false;
+                }
+
+                $di = new \DirectoryIterator($folderName);
+
+                /** @var \DirectoryIterator $item */
+                foreach ($di as $item) {
+                    if ($item->isDot()) {
+                        continue;
+                    }
+
+                    if ($item->isDir()) {
+                        $status = self::delete($item->getPathname());
+
+                        if (!$status) {
+                            return false;
+                        }
+
+                        continue;
+                    }
+
+                    clearFileInOPCache($item->getPathname());
+
+                    @unlink($item->getPathname());
+                }
+
+                return @rmdir($folderName);
+            }
+        }
+    }
+
+    if (!class_exists('\Joomla\CMS\Filesystem\File')) {
+        class_alias('\\Joomla\\Filesystem\\File', '\\Joomla\\CMS\\Filesystem\\File');
+    }
+
+    if (!class_exists('\Joomla\CMS\Filesystem\Folder')) {
+        class_alias('\\Joomla\\Filesystem\\Folder', '\\Joomla\\CMS\\Filesystem\\Folder');
+    }
+}
+
+namespace Joomla\CMS\Language
+{
+    // Fake the Text class - we aren't going to show errors to people anyhow
+    if (!class_exists('\Joomla\CMS\Language\Text')) {
+        /**
+         * Text mock class
+         *
+         * @since  3.5.1
+         */
+        abstract class Text
+        {
+            /**
+             * No need for translations in a non-interactive script, so always return an empty string here
+             *
+             * @param   string  $text  A language constant
+             *
+             * @return  string
+             *
+             * @since   3.5.1
+             */
+            public static function sprintf(string $text): string
+            {
+                return '';
+            }
+        }
+    }
+}

administrator/components/com_joomlaupdate/joomlaupdate.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<extension type="component" method="upgrade">
+	<name>com_joomlaupdate</name>
+	<author>Joomla! Project</author>
+	<creationDate>2021-08</creationDate>
+	<copyright>(C) 2012 Open Source Matters, Inc.</copyright>
+	<license>GNU General Public License version 2 or later; see LICENSE.txt</license>
+	<authorEmail>admin@joomla.org</authorEmail>
+	<authorUrl>www.joomla.org</authorUrl>
+	<version>4.0.3</version>
+	<description>COM_JOOMLAUPDATE_XML_DESCRIPTION</description>
+	<namespace path="src">Joomla\Component\Joomlaupdate</namespace>
+	<media destination="com_joomlaupdate" folder="media">
+		<folder>js</folder>
+	</media>
+	<administration>
+		<files folder="admin">
+			<filename>config.xml</filename>
+			<filename>extract.php</filename>
+			<filename>finalisation.php</filename>
+			<folder>services</folder>
+			<folder>src</folder>
+			<folder>tmpl</folder>
+		</files>
+		<languages folder="admin">
+			<language tag="en-GB">language/en-GB/com_joomlaupdate.ini</language>
+			<language tag="en-GB">language/en-GB/com_joomlaupdate.sys.ini</language>
+		</languages>
+	</administration>
+	<updateservers>
+		<server type="extension" name="Joomla! Update Component">https://update.joomla.org/core/extensions/com_joomlaupdate.xml</server>
+	</updateservers>
+</extension>

administrator/components/com_joomlaupdate/services/provider.php

@@ -0,0 +1,53 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2018 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\Dispatcher\ComponentDispatcherFactoryInterface;
+use Joomla\CMS\Extension\ComponentInterface;
+use Joomla\CMS\Extension\MVCComponent;
+use Joomla\CMS\Extension\Service\Provider\ComponentDispatcherFactory;
+use Joomla\CMS\Extension\Service\Provider\MVCFactory;
+use Joomla\CMS\MVC\Factory\MVCFactoryInterface;
+use Joomla\DI\Container;
+use Joomla\DI\ServiceProviderInterface;
+
+/**
+ * The content service provider.
+ *
+ * @since  4.0.0
+ */
+return new class () implements ServiceProviderInterface {
+    /**
+     * Registers the service provider with a DI container.
+     *
+     * @param   Container  $container  The DI container.
+     *
+     * @return  void
+     *
+     * @since   4.0.0
+     */
+    public function register(Container $container)
+    {
+        $container->registerServiceProvider(new MVCFactory('\\Joomla\\Component\\Joomlaupdate'));
+        $container->registerServiceProvider(new ComponentDispatcherFactory('\\Joomla\\Component\\Joomlaupdate'));
+
+        $container->set(
+            ComponentInterface::class,
+            function (Container $container) {
+                $component = new MVCComponent($container->get(ComponentDispatcherFactoryInterface::class));
+
+                $component->setMVCFactory($container->get(MVCFactoryInterface::class));
+
+                return $component;
+            }
+        );
+    }
+};

administrator/components/com_joomlaupdate/src/Controller/DisplayController.php

@@ -0,0 +1,119 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2012 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\Component\Joomlaupdate\Administrator\Controller;
+
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\MVC\Controller\BaseController;
+use Joomla\CMS\Response\JsonResponse;
+use Joomla\CMS\Router\Route;
+
+// phpcs:disable PSR1.Files.SideEffects
+\defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
+
+/**
+ * Joomla! Update Controller
+ *
+ * @since  2.5.4
+ */
+class DisplayController extends BaseController
+{
+    /**
+     * Method to display a view.
+     *
+     * @param   boolean  $cachable   If true, the view output will be cached.
+     * @param   array    $urlparams  An array of safe URL parameters and their variable types.
+     *                   @see        \Joomla\CMS\Filter\InputFilter::clean() for valid values.
+     *
+     * @return  static   This object to support chaining.
+     *
+     * @since   2.5.4
+     */
+    public function display($cachable = false, $urlparams = false)
+    {
+        // Get the document object.
+        $document = $this->app->getDocument();
+
+        // Set the default view name and format from the Request.
+        $vName   = $this->input->get('view', 'Joomlaupdate');
+        $vFormat = $document->getType();
+        $lName   = $this->input->get('layout', 'default', 'string');
+
+        // Get and render the view.
+        if ($view = $this->getView($vName, $vFormat)) {
+            // Only super user can access file upload
+            if ($view == 'upload' && !$this->app->getIdentity()->authorise('core.admin', 'com_joomlaupdate')) {
+                $this->app->redirect(Route::_('index.php?option=com_joomlaupdate', true));
+            }
+
+            // Get the model for the view.
+            /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+            $model = $this->getModel('Update');
+
+            /** @var ?\Joomla\Component\Installer\Administrator\Model\WarningsModel $warningsModel */
+            $warningsModel = $this->app->bootComponent('com_installer')
+                ->getMVCFactory()->createModel('Warnings', 'Administrator', ['ignore_request' => true]);
+
+            if ($warningsModel !== null) {
+                $view->setModel($warningsModel, false);
+            }
+
+            // Check for update result
+            if ($lName === 'complete') {
+                $state = $model->getState();
+                $state->set('update_finished_with_error', $this->app->getUserState('com_joomlaupdate.update_finished_with_error'));
+                $state->set('update_errors', (array) $this->app->getUserState('com_joomlaupdate.update_errors', []));
+                $state->set('update_channel_reset', $this->app->getUserState('com_joomlaupdate.update_channel_reset'));
+                $state->set('installer_message', $this->app->getUserState('com_joomlaupdate.installer_message'));
+                $state->set('log_file', $this->app->get('log_path') . '/joomla_update.php');
+            }
+
+            // Perform update source preference check and refresh update information.
+            $model->applyUpdateSite();
+            $model->refreshUpdates();
+
+            // Push the model into the view (as default).
+            $view->setModel($model, true);
+            $view->setLayout($lName);
+
+            // Push document object into the view.
+            $view->document = $document;
+            $view->display();
+        }
+
+        return $this;
+    }
+
+    /**
+     * Provide the data for a badge in a menu item via JSON
+     *
+     * @return  void
+     *
+     * @since   4.0.0
+     * @throws  \Exception
+     */
+    public function getMenuBadgeData()
+    {
+        if (!$this->app->getIdentity()->authorise('core.manage', 'com_joomlaupdate')) {
+            throw new \Exception(Text::_('JGLOBAL_AUTH_ACCESS_DENIED'));
+        }
+
+        $model = $this->getModel('Update');
+
+        $model->refreshUpdates();
+
+        $joomlaUpdate = $model->getUpdateInformation();
+
+        $hasUpdate = $joomlaUpdate['hasUpdate'] ? $joomlaUpdate['latest'] : '';
+
+        echo new JsonResponse($hasUpdate);
+    }
+}

administrator/components/com_joomlaupdate/src/Controller/UpdateController.php

@@ -0,0 +1,715 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2012 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\Component\Joomlaupdate\Administrator\Controller;
+
+use Joomla\CMS\Factory;
+use Joomla\CMS\Installer\Installer;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Log\Log;
+use Joomla\CMS\MVC\Controller\BaseController;
+use Joomla\CMS\Response\JsonResponse;
+use Joomla\CMS\Session\Session;
+use Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel;
+
+// phpcs:disable PSR1.Files.SideEffects
+\defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
+
+/**
+ * The Joomla! update controller for the Update view
+ *
+ * @since  2.5.4
+ */
+class UpdateController extends BaseController
+{
+    /**
+     * Performs the download of the update package
+     *
+     * @return  void
+     *
+     * @since   2.5.4
+     */
+    public function download()
+    {
+        $this->checkToken();
+
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model = $this->getModel('Update');
+        $user  = $this->app->getIdentity();
+
+        // Make sure logging is working before continue
+        try {
+            Log::add('Test logging', Log::INFO, 'Update');
+        } catch (\Throwable $e) {
+            $message = Text::sprintf('COM_JOOMLAUPDATE_UPDATE_LOGGING_TEST_FAIL', $e->getMessage());
+            $this->setRedirect('index.php?option=com_joomlaupdate', $message, 'error');
+            return;
+        }
+
+        Log::add(Text::sprintf('COM_JOOMLAUPDATE_UPDATE_LOG_START', $user->id, $user->name, \JVERSION), Log::INFO, 'Update');
+
+        $result = $model->download();
+        $file   = $result['basename'];
+
+        $message     = null;
+        $messageType = null;
+
+        // The versions mismatch (Use \JVERSION as target version when not set in case of reinstall core files)
+        if ($result['version'] !== $this->input->get('targetVersion', \JVERSION, 'string')) {
+            $message     = Text::_('COM_JOOMLAUPDATE_VIEW_UPDATE_VERSION_WRONG');
+            $messageType = 'error';
+            $url         = 'index.php?option=com_joomlaupdate';
+
+            $this->app->setUserState('com_joomlaupdate.file', null);
+            $this->setRedirect($url, $message, $messageType);
+
+            Log::add($message, Log::ERROR, 'Update');
+
+            return;
+        }
+
+        // The validation was not successful so stop.
+        if ($result['check'] === false) {
+            $message     = Text::_('COM_JOOMLAUPDATE_VIEW_UPDATE_CHECKSUM_WRONG');
+            $messageType = 'error';
+            $url         = 'index.php?option=com_joomlaupdate';
+
+            $this->app->setUserState('com_joomlaupdate.file', null);
+            $this->setRedirect($url, $message, $messageType);
+
+            Log::add($message, Log::ERROR, 'Update');
+
+            return;
+        }
+
+        if ($file) {
+            $this->app->setUserState('com_joomlaupdate.file', $file);
+            $url = 'index.php?option=com_joomlaupdate&task=update.install&' . $this->app->getSession()->getFormToken() . '=1';
+
+            Log::add(Text::sprintf('COM_JOOMLAUPDATE_UPDATE_LOG_FILE', $file), Log::INFO, 'Update');
+        } else {
+            $this->app->setUserState('com_joomlaupdate.file', null);
+            $url         = 'index.php?option=com_joomlaupdate';
+            $message     = Text::_('COM_JOOMLAUPDATE_VIEW_UPDATE_DOWNLOADFAILED');
+            $messageType = 'error';
+        }
+
+        $this->setRedirect($url, $message, $messageType);
+    }
+
+    /**
+     * Start the installation of the new Joomla! version
+     *
+     * @return  void
+     *
+     * @since   2.5.4
+     */
+    public function install()
+    {
+        $this->checkToken('get');
+        $this->app->setUserState('com_joomlaupdate.oldversion', JVERSION);
+
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model = $this->getModel('Update');
+
+        Log::add(Text::_('COM_JOOMLAUPDATE_UPDATE_LOG_INSTALL'), Log::INFO, 'Update');
+
+        $file = $this->app->getUserState('com_joomlaupdate.file', null);
+        $model->createRestorationFile($file);
+
+        $this->display();
+    }
+
+    /**
+     * Finalise the upgrade by running the necessary scripts
+     *
+     * @return  void
+     *
+     * @since   2.5.4
+     */
+    public function finalise()
+    {
+        /*
+         * Finalize with login page. Used for pre-token check versions
+         * to allow updates without problems but with a maximum of security.
+         */
+        if (!Session::checkToken('get')) {
+            $this->setRedirect('index.php?option=com_joomlaupdate&view=update&layout=finaliseconfirm');
+
+            return;
+        }
+
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model = $this->getModel('Update');
+
+        try {
+            $model->finaliseUpgrade();
+        } catch (\Throwable $e) {
+            $model->collectError('finaliseUpgrade', $e);
+        }
+
+        // Reset update source from "Joomla Next" to "Default"
+        $this->app->setUserState('com_joomlaupdate.update_channel_reset', $model->resetUpdateSource());
+
+        // Check for update errors
+        if ($model->getErrors()) {
+            // The errors already should be logged at this point
+            // Collect a messages to show them later in the complete page
+            $errors = [];
+            foreach ($model->getErrors() as $error) {
+                $errors[] = $error->getMessage();
+            }
+
+            $this->app->setUserState('com_joomlaupdate.update_finished_with_error', true);
+            $this->app->setUserState('com_joomlaupdate.update_errors', $errors);
+        }
+
+        // Check for captured output messages in the installer
+        $msg = Installer::getInstance()->get('extension_message');
+        if ($msg) {
+            $this->app->setUserState('com_joomlaupdate.installer_message', $msg);
+        }
+
+        $url = 'index.php?option=com_joomlaupdate&task=update.cleanup&' . Session::getFormToken() . '=1';
+        $this->setRedirect($url);
+    }
+
+    /**
+     * Clean up after ourselves
+     *
+     * @return  void
+     *
+     * @since   2.5.4
+     */
+    public function cleanup()
+    {
+        /*
+         * Cleanup with login page. Used for pre-token check versions to be able to update
+         * from =< 3.2.7 to allow updates without problems but with a maximum of security.
+         */
+        if (!Session::checkToken('get')) {
+            $this->setRedirect('index.php?option=com_joomlaupdate&view=update&layout=finaliseconfirm');
+
+            return;
+        }
+
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model = $this->getModel('Update');
+
+        try {
+            $model->cleanUp();
+        } catch (\Throwable $e) {
+            $model->collectError('cleanUp', $e);
+        }
+
+        // Check for update errors
+        if ($model->getErrors()) {
+            // The errors already should be logged at this point
+            // Collect a messages to show them later in the complete page
+            $errors = $this->app->getUserState('com_joomlaupdate.update_errors', []);
+            foreach ($model->getErrors() as $error) {
+                $errors[] = $error->getMessage();
+            }
+
+            $this->app->setUserState('com_joomlaupdate.update_finished_with_error', true);
+            $this->app->setUserState('com_joomlaupdate.update_errors', $errors);
+        }
+
+        $url = 'index.php?option=com_joomlaupdate&view=joomlaupdate&layout=complete';
+
+        // In case for errored update, redirect to component view
+        if ($this->app->getUserState('com_joomlaupdate.update_finished_with_error')) {
+            $url .= '&tmpl=component';
+        }
+
+        $this->setRedirect($url);
+    }
+
+    /**
+     * Purges updates.
+     *
+     * @return  void
+     *
+     * @since   3.0
+     */
+    public function purge()
+    {
+        // Check for request forgeries
+        $this->checkToken('request');
+
+        // Purge updates
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model = $this->getModel('Update');
+        $model->purge();
+
+        $url = 'index.php?option=com_joomlaupdate';
+        $this->setRedirect($url, $model->_message);
+    }
+
+    /**
+     * Uploads an update package to the temporary directory, under a random name
+     *
+     * @return  void
+     *
+     * @since   3.6.0
+     */
+    public function upload()
+    {
+        // Check for request forgeries
+        $this->checkToken();
+
+        // Did a non Super User tried to upload something (a.k.a. pathetic hacking attempt)?
+        $this->app->getIdentity()->authorise('core.admin') or jexit(Text::_('JLIB_APPLICATION_ERROR_ACCESS_FORBIDDEN'));
+
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model = $this->getModel('Update');
+
+        // Make sure logging is working before continue
+        try {
+            Log::add('Test logging', Log::INFO, 'Update');
+        } catch (\Throwable $e) {
+            $message = Text::sprintf('COM_JOOMLAUPDATE_UPDATE_LOGGING_TEST_FAIL', $e->getMessage());
+            $this->setRedirect('index.php?option=com_joomlaupdate', $message, 'error');
+            return;
+        }
+
+        Log::add(Text::_('COM_JOOMLAUPDATE_UPDATE_LOG_UPLOAD'), Log::INFO, 'Update');
+
+        try {
+            $model->upload();
+        } catch (\RuntimeException $e) {
+            $url = 'index.php?option=com_joomlaupdate';
+            $this->setRedirect($url, $e->getMessage(), 'error');
+
+            return;
+        }
+
+        $token = Session::getFormToken();
+        $url   = 'index.php?option=com_joomlaupdate&task=update.captive&' . $token . '=1';
+        $this->setRedirect($url);
+    }
+
+    /**
+     * Checks there is a valid update package and redirects to the captive view for super admin authentication.
+     *
+     * @return  void
+     *
+     * @since   3.6.0
+     */
+    public function captive()
+    {
+        // Check for request forgeries
+        $this->checkToken('get');
+
+        // Did a non Super User tried to upload something (a.k.a. pathetic hacking attempt)?
+        if (!$this->app->getIdentity()->authorise('core.admin')) {
+            throw new \RuntimeException(Text::_('JLIB_APPLICATION_ERROR_ACCESS_FORBIDDEN'), 403);
+        }
+
+        // Do I really have an update package?
+        $tempFile = $this->app->getUserState('com_joomlaupdate.temp_file', null);
+
+        if (empty($tempFile) || !is_file($tempFile)) {
+            throw new \RuntimeException(Text::_('JLIB_APPLICATION_ERROR_ACCESS_FORBIDDEN'), 403);
+        }
+
+        $this->input->set('view', 'upload');
+        $this->input->set('layout', 'captive');
+
+        $this->display();
+    }
+
+    /**
+     * Checks the admin has super administrator privileges and then proceeds with the update.
+     *
+     * @return  void
+     *
+     * @since   3.6.0
+     */
+    public function confirm()
+    {
+        // Check for request forgeries
+        $this->checkToken();
+
+        // Did a non Super User tried to upload something (a.k.a. pathetic hacking attempt)?
+        if (!$this->app->getIdentity()->authorise('core.admin')) {
+            throw new \RuntimeException(Text::_('JLIB_APPLICATION_ERROR_ACCESS_FORBIDDEN'), 403);
+        }
+
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model = $this->getModel('Update');
+
+        // Get the captive file before the session resets
+        $tempFile = $this->app->getUserState('com_joomlaupdate.temp_file', null);
+
+        // Do I really have an update package?
+        if (!$model->captiveFileExists()) {
+            throw new \RuntimeException(Text::_('JLIB_APPLICATION_ERROR_ACCESS_FORBIDDEN'), 403);
+        }
+
+        // Try to log in
+        $credentials = [
+            'username'  => $this->input->post->get('username', '', 'username'),
+            'password'  => $this->input->post->get('passwd', '', 'raw'),
+            'secretkey' => $this->input->post->get('secretkey', '', 'raw'),
+        ];
+
+        $result = $model->captiveLogin($credentials);
+
+        if (!$result) {
+            $model->removePackageFiles();
+
+            throw new \RuntimeException(Text::_('JLIB_APPLICATION_ERROR_ACCESS_FORBIDDEN'), 403);
+        }
+
+        // Set the update source in the session
+        $this->app->setUserState('com_joomlaupdate.file', basename($tempFile));
+
+        try {
+            Log::add(Text::sprintf('COM_JOOMLAUPDATE_UPDATE_LOG_FILE', $tempFile), Log::INFO, 'Update');
+        } catch (\RuntimeException $exception) {
+            // Informational log only
+        }
+
+        // Redirect to the actual update page
+        $url = 'index.php?option=com_joomlaupdate&task=update.install&' . Session::getFormToken() . '=1';
+        $this->setRedirect($url);
+    }
+
+    /**
+     * Method to display a view.
+     *
+     * @param   boolean  $cachable   If true, the view output will be cached
+     * @param   array    $urlparams  An array of safe URL parameters and their variable types.
+     *                   @see        \Joomla\CMS\Filter\InputFilter::clean() for valid values.
+     *
+     * @return  static  This object to support chaining.
+     *
+     * @since   2.5.4
+     */
+    public function display($cachable = false, $urlparams = [])
+    {
+        // Get the document object.
+        $document = $this->app->getDocument();
+
+        // Set the default view name and format from the Request.
+        $vName   = $this->input->get('view', 'update');
+        $vFormat = $document->getType();
+        $lName   = $this->input->get('layout', 'default', 'string');
+
+        // Get and render the view.
+        if ($view = $this->getView($vName, $vFormat)) {
+            // Get the model for the view.
+            /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+            $model = $this->getModel('Update');
+
+            // Push the model into the view (as default).
+            $view->setModel($model, true);
+            $view->setLayout($lName);
+
+            // Push document object into the view.
+            $view->document = $document;
+            $view->display();
+        }
+
+        return $this;
+    }
+
+    /**
+     * Checks the admin has super administrator privileges and then proceeds with the final & cleanup steps.
+     *
+     * @return  void
+     *
+     * @since   3.6.3
+     */
+    public function finaliseconfirm()
+    {
+        // Check for request forgeries
+        $this->checkToken();
+
+        // Did a non Super User try do this?
+        if (!$this->app->getIdentity()->authorise('core.admin')) {
+            throw new \RuntimeException(Text::_('JLIB_APPLICATION_ERROR_ACCESS_FORBIDDEN'), 403);
+        }
+
+        // Get the model
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model = $this->getModel('Update');
+
+        // Try to log in
+        $credentials = [
+            'username'  => $this->input->post->get('username', '', 'username'),
+            'password'  => $this->input->post->get('passwd', '', 'raw'),
+            'secretkey' => $this->input->post->get('secretkey', '', 'raw'),
+        ];
+
+        $result = $model->captiveLogin($credentials);
+
+        // The login fails?
+        if (!$result) {
+            $this->setMessage(Text::_('JGLOBAL_AUTH_INVALID_PASS'), 'warning');
+            $this->setRedirect('index.php?option=com_joomlaupdate&view=update&layout=finaliseconfirm');
+
+            return;
+        }
+
+        // Redirect back to the actual finalise page
+        $this->setRedirect('index.php?option=com_joomlaupdate&task=update.finalise&' . Session::getFormToken() . '=1');
+    }
+
+    /**
+     * Fetch Extension update XML proxy. Used to prevent Access-Control-Allow-Origin errors.
+     * Prints a JSON string.
+     * Called from JS.
+     *
+     * @since       3.10.0
+     *
+     * @deprecated  4.3 will be removed in 6.0
+     *              Use batchextensioncompatibility instead.
+     *              Example: $updateController->batchextensioncompatibility();
+     *
+     * @return void
+     */
+    public function fetchExtensionCompatibility()
+    {
+        $extensionID          = $this->input->get('extension-id', '', 'DEFAULT');
+        $joomlaTargetVersion  = $this->input->get('joomla-target-version', '', 'DEFAULT');
+        $joomlaCurrentVersion = $this->input->get('joomla-current-version', '', JVERSION);
+        $extensionVersion     = $this->input->get('extension-version', '', 'DEFAULT');
+
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model                      = $this->getModel('Update');
+        $upgradeCompatibilityStatus = $model->fetchCompatibility($extensionID, $joomlaTargetVersion);
+        $currentCompatibilityStatus = $model->fetchCompatibility($extensionID, $joomlaCurrentVersion);
+        $upgradeUpdateVersion       = false;
+        $currentUpdateVersion       = false;
+
+        $upgradeWarning = 0;
+
+        if ($upgradeCompatibilityStatus->state == 1 && !empty($upgradeCompatibilityStatus->compatibleVersions)) {
+            $upgradeUpdateVersion = end($upgradeCompatibilityStatus->compatibleVersions);
+        }
+
+        if ($currentCompatibilityStatus->state == 1 && !empty($currentCompatibilityStatus->compatibleVersions)) {
+            $currentUpdateVersion = end($currentCompatibilityStatus->compatibleVersions);
+        }
+
+        if ($upgradeUpdateVersion !== false) {
+            $upgradeOldestVersion = $upgradeCompatibilityStatus->compatibleVersions[0];
+
+            if ($currentUpdateVersion !== false) {
+                // If there are updates compatible with both CMS versions use these
+                $bothCompatibleVersions = array_values(
+                    array_intersect($upgradeCompatibilityStatus->compatibleVersions, $currentCompatibilityStatus->compatibleVersions)
+                );
+
+                if (!empty($bothCompatibleVersions)) {
+                    $upgradeOldestVersion = $bothCompatibleVersions[0];
+                    $upgradeUpdateVersion = end($bothCompatibleVersions);
+                }
+            }
+
+            if (version_compare($upgradeOldestVersion, $extensionVersion, '>')) {
+                // Installed version is empty or older than the oldest compatible update: Update required
+                $resultGroup = 2;
+            } else {
+                // Current version is compatible
+                $resultGroup = 3;
+            }
+
+            if ($currentUpdateVersion !== false && version_compare($upgradeUpdateVersion, $currentUpdateVersion, '<')) {
+                // Special case warning when version compatible with target is lower than current
+                $upgradeWarning = 2;
+            }
+        } elseif ($currentUpdateVersion !== false) {
+            // No compatible version for target version but there is a compatible version for current version
+            $resultGroup = 1;
+        } else {
+            // No update server available
+            $resultGroup = 1;
+        }
+
+        // Do we need to capture
+        $combinedCompatibilityStatus = [
+            'upgradeCompatibilityStatus' => (object) [
+                'state'             => $upgradeCompatibilityStatus->state,
+                'compatibleVersion' => $upgradeUpdateVersion,
+            ],
+            'currentCompatibilityStatus' => (object) [
+                'state'             => $currentCompatibilityStatus->state,
+                'compatibleVersion' => $currentUpdateVersion,
+            ],
+            'resultGroup'    => $resultGroup,
+            'upgradeWarning' => $upgradeWarning,
+        ];
+
+        $this->app           = Factory::getApplication();
+        $this->app->mimeType = 'application/json';
+        $this->app->charSet  = 'utf-8';
+        $this->app->setHeader('Content-Type', $this->app->mimeType . '; charset=' . $this->app->charSet);
+        $this->app->sendHeaders();
+
+        try {
+            echo new JsonResponse($combinedCompatibilityStatus);
+        } catch (\Exception $e) {
+            echo $e;
+        }
+
+        $this->app->close();
+    }
+
+    /**
+     * Determines the compatibility information for a number of extensions.
+     *
+     * Called by the Joomla Update JavaScript (PreUpdateChecker.checkNextChunk).
+     *
+     * @return  void
+     * @since   4.2.0
+     *
+     */
+    public function batchextensioncompatibility()
+    {
+        $joomlaTargetVersion  = $this->input->post->get('joomla-target-version', '', 'DEFAULT');
+        $joomlaCurrentVersion = $this->input->post->get('joomla-current-version', JVERSION);
+        $extensionInformation = $this->input->post->get('extensions', []);
+
+        /** @var \Joomla\Component\Joomlaupdate\Administrator\Model\UpdateModel $model */
+        $model = $this->getModel('Update');
+
+        $extensionResults = [];
+        $leftover         = [];
+        $startTime        = microtime(true);
+
+        foreach ($extensionInformation as $information) {
+            // Only process an extension if we have spent less than 5 seconds already
+            $currentTime = microtime(true);
+
+            if ($currentTime - $startTime > 5.0) {
+                $leftover[] = $information;
+
+                continue;
+            }
+
+            // Get the extension information and fetch its compatibility information
+            $extensionID                = $information['eid'] ?: '';
+            $extensionVersion           = $information['version'] ?: '';
+            $upgradeCompatibilityStatus = $model->fetchCompatibility($extensionID, $joomlaTargetVersion);
+            $currentCompatibilityStatus = $model->fetchCompatibility($extensionID, $joomlaCurrentVersion);
+            $upgradeUpdateVersion       = false;
+            $currentUpdateVersion       = false;
+            $upgradeWarning             = 0;
+
+            if ($upgradeCompatibilityStatus->state == 1 && !empty($upgradeCompatibilityStatus->compatibleVersions)) {
+                $upgradeUpdateVersion = end($upgradeCompatibilityStatus->compatibleVersions);
+            }
+
+            if ($currentCompatibilityStatus->state == 1 && !empty($currentCompatibilityStatus->compatibleVersions)) {
+                $currentUpdateVersion = end($currentCompatibilityStatus->compatibleVersions);
+            }
+
+            if ($upgradeUpdateVersion !== false) {
+                $upgradeOldestVersion = $upgradeCompatibilityStatus->compatibleVersions[0];
+
+                if ($currentUpdateVersion !== false) {
+                    // If there are updates compatible with both CMS versions use these
+                    $bothCompatibleVersions = array_values(
+                        array_intersect($upgradeCompatibilityStatus->compatibleVersions, $currentCompatibilityStatus->compatibleVersions)
+                    );
+
+                    if (!empty($bothCompatibleVersions)) {
+                        $upgradeOldestVersion = $bothCompatibleVersions[0];
+                        $upgradeUpdateVersion = end($bothCompatibleVersions);
+                    }
+                }
+
+                if (version_compare($upgradeOldestVersion, $extensionVersion, '>')) {
+                    // Installed version is empty or older than the oldest compatible update: Update required
+                    $resultGroup = 2;
+                } else {
+                    // Current version is compatible
+                    $resultGroup = 3;
+                }
+
+                if ($currentUpdateVersion !== false && version_compare($upgradeUpdateVersion, $currentUpdateVersion, '<')) {
+                    // Special case warning when version compatible with target is lower than current
+                    $upgradeWarning = 2;
+                }
+            } elseif ($currentUpdateVersion !== false) {
+                // No compatible version for target version but there is a compatible version for current version
+                $resultGroup = 1;
+            } else {
+                // No update server available
+                $resultGroup = 1;
+            }
+
+            // Do we need to capture
+            $extensionResults[] = [
+                'id'                         => $extensionID,
+                'upgradeCompatibilityStatus' => (object) [
+                    'state'             => $upgradeCompatibilityStatus->state,
+                    'compatibleVersion' => $upgradeUpdateVersion,
+                ],
+                'currentCompatibilityStatus' => (object) [
+                    'state'             => $currentCompatibilityStatus->state,
+                    'compatibleVersion' => $currentUpdateVersion,
+                ],
+                'resultGroup'    => $resultGroup,
+                'upgradeWarning' => $upgradeWarning,
+            ];
+        }
+
+        $this->app->mimeType = 'application/json';
+        $this->app->charSet  = 'utf-8';
+        $this->app->setHeader('Content-Type', $this->app->mimeType . '; charset=' . $this->app->charSet);
+        $this->app->sendHeaders();
+
+        try {
+            $return = [
+                'compatibility' => $extensionResults,
+                'extensions'    => $leftover,
+            ];
+
+            echo new JsonResponse($return);
+        } catch (\Exception $e) {
+            echo $e;
+        }
+
+        $this->app->close();
+    }
+
+    /**
+     * Fetch and report updates in \JSON format, for AJAX requests
+     *
+     * @return  void
+     *
+     * @since   3.10.10
+     */
+    public function ajax()
+    {
+        if (!Session::checkToken('get')) {
+            $this->app->setHeader('status', 403, true);
+            $this->app->sendHeaders();
+            echo Text::_('JINVALID_TOKEN_NOTICE');
+            $this->app->close();
+        }
+
+        /** @var UpdateModel $model */
+        $model      = $this->getModel('Update');
+        $updateInfo = $model->getUpdateInformation();
+
+        $update   = [];
+        $update[] = ['version' => $updateInfo['latest']];
+
+        echo json_encode($update);
+
+        $this->app->close();
+    }
+}

administrator/components/com_joomlaupdate/src/Dispatcher/Dispatcher.php

@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2005 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\Component\Joomlaupdate\Administrator\Dispatcher;
+
+use Joomla\CMS\Access\Exception\NotAllowed;
+use Joomla\CMS\Dispatcher\ComponentDispatcher;
+
+// phpcs:disable PSR1.Files.SideEffects
+\defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
+
+/**
+ * ComponentDispatcher class for com_joomlaupdate
+ *
+ * @since  4.0.0
+ */
+class Dispatcher extends ComponentDispatcher
+{
+    /**
+     * Joomla Update is checked for global core.admin rights - not the usual core.manage for the component
+     *
+     * @return  void
+     */
+    protected function checkAccess()
+    {
+        // Check the user has permission to access this component if in the backend
+        if ($this->app->isClient('administrator') && !$this->app->getIdentity()->authorise('core.admin')) {
+            throw new NotAllowed($this->app->getLanguage()->_('JERROR_ALERTNOAUTHOR'), 403);
+        }
+    }
+}

administrator/components/com_joomlaupdate/src/View/Joomlaupdate/HtmlView.php

@@ -0,0 +1,325 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2012 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\Component\Joomlaupdate\Administrator\View\Joomlaupdate;
+
+use Joomla\CMS\Component\ComponentHelper;
+use Joomla\CMS\Factory;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\MVC\View\HtmlView as BaseHtmlView;
+use Joomla\CMS\Toolbar\ToolbarHelper;
+use Joomla\CMS\Version;
+
+// phpcs:disable PSR1.Files.SideEffects
+\defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
+
+/**
+ * Joomla! Update's Default View
+ *
+ * @since  2.5.4
+ */
+class HtmlView extends BaseHtmlView
+{
+    /**
+     * An array with the Joomla! update information.
+     *
+     * @var    array
+     *
+     * @since  3.6.0
+     */
+    protected $updateInfo = null;
+
+    /**
+     * PHP options.
+     *
+     * @var   array  Array of PHP config options
+     *
+     * @since 3.10.0
+     */
+    protected $phpOptions = null;
+
+    /**
+     * PHP settings.
+     *
+     * @var   array  Array of PHP settings
+     *
+     * @since 3.10.0
+     */
+    protected $phpSettings = null;
+
+    /**
+     * Non Core Extensions.
+     *
+     * @var   array  Array of Non-Core-Extensions
+     *
+     * @since 3.10.0
+     */
+    protected $nonCoreExtensions = null;
+
+    /**
+     * The model state
+     *
+     * @var   \Joomla\Registry\Registry
+     *
+     * @since  4.0.0
+     */
+    protected $state;
+
+    /**
+     * Flag if the update component itself has to be updated
+     *
+     * @var boolean  True when update is available otherwise false
+     *
+     * @since 4.0.0
+     */
+    protected $selfUpdateAvailable = false;
+
+    /**
+     * The default admin template for the major version of Joomla that should be used when
+     * upgrading to the next major version of Joomla
+     *
+     * @var string
+     *
+     * @since 4.0.0
+     */
+    protected $defaultBackendTemplate = 'atum';
+
+    /**
+     * Flag if default backend template is being used
+     *
+     * @var boolean  True when default backend template is being used
+     *
+     * @since 4.0.0
+     */
+    protected $isDefaultBackendTemplate = false;
+
+    /**
+     * A special prefix used for the emptystate layout variable
+     *
+     * @var string  The prefix
+     *
+     * @since 4.0.0
+     */
+    protected $messagePrefix = '';
+
+    /**
+     * A special text used for the emptystate layout to explain why there is no download
+     *
+     * @var string  The message
+     *
+     * @since 4.4.0
+     */
+    protected $reasonNoDownload = '';
+
+    /**
+     * Details on failed PHP or DB version requirements to be shown in the emptystate layout when there is no download
+     *
+     * @var \stdClass  PHP and database requirements from the update manifest
+     *
+     * @since 4.4.2
+     */
+    protected $detailsNoDownload;
+
+    /**
+     * List of non core critical plugins
+     *
+     * @var    \stdClass[]
+     * @since  4.0.0
+     */
+    protected $nonCoreCriticalPlugins = [];
+
+    /**
+     * Should I disable the confirmation checkbox for pre-update extension version checks?
+     *
+     * @var   boolean
+     * @since 4.2.0
+     */
+    protected $noVersionCheck = false;
+
+    /**
+     * Should I disable the confirmation checkbox for taking a backup before updating?
+     *
+     * @var   boolean
+     * @since 4.2.0
+     */
+    protected $noBackupCheck = false;
+
+    /**
+     * Renders the view
+     *
+     * @param   string  $tpl  Template name
+     *
+     * @return void
+     *
+     * @since  2.5.4
+     */
+    public function display($tpl = null)
+    {
+        $this->updateInfo          = $this->get('UpdateInformation');
+        $this->selfUpdateAvailable = $this->get('CheckForSelfUpdate');
+
+        // Get results of pre update check evaluations
+        $model                          = $this->getModel();
+        $this->phpOptions               = $this->get('PhpOptions');
+        $this->phpSettings              = $this->get('PhpSettings');
+        $this->nonCoreExtensions        = $this->get('NonCoreExtensions');
+        $this->isDefaultBackendTemplate = (bool) $model->isTemplateActive($this->defaultBackendTemplate);
+        $nextMajorVersion               = Version::MAJOR_VERSION + 1;
+
+        // The critical plugins check is only available for major updates.
+        if (version_compare($this->updateInfo['latest'], (string) $nextMajorVersion, '>=')) {
+            $this->nonCoreCriticalPlugins = $this->get('NonCorePlugins');
+        }
+
+        // Set to true if a required PHP option is not ok
+        $isCritical = false;
+
+        foreach ($this->phpOptions as $option) {
+            if (!$option->state) {
+                $isCritical = true;
+                break;
+            }
+        }
+
+        $this->state = $this->get('State');
+
+        $hasUpdate   = !empty($this->updateInfo['hasUpdate']);
+        $hasDownload = isset($this->updateInfo['object']->downloadurl->_data);
+
+        // Fresh update, show it
+        if ($this->getLayout() == 'complete') {
+            // Complete message, nothing to do here
+        } elseif ($this->selfUpdateAvailable) {
+            // There is an update for the updater itself. So we have to update it first
+            $this->setLayout('selfupdate');
+        } elseif (!$hasDownload || !$hasUpdate) {
+            // Could be that we have a download file but no update, so we offer a re-install
+            if ($hasDownload) {
+                // We can reinstall if we have a URL but no update
+                $this->setLayout('reinstall');
+            } else {
+                // No download available
+                if ($hasUpdate) {
+                    $this->messagePrefix     = '_NODOWNLOAD';
+                    $this->reasonNoDownload  = 'COM_JOOMLAUPDATE_NODOWNLOAD_EMPTYSTATE_REASON';
+                    $this->detailsNoDownload = $this->updateInfo['object']->get('otherUpdateInfo');
+                }
+
+                $this->setLayout('noupdate');
+            }
+        } elseif ($this->getLayout() != 'update' && ($isCritical || $this->shouldDisplayPreUpdateCheck())) {
+            // Here we have now two options: preupdatecheck or update
+            $this->setLayout('preupdatecheck');
+        } else {
+            $this->setLayout('update');
+        }
+
+        if (\in_array($this->getLayout(), ['preupdatecheck', 'update', 'upload'])) {
+            $language = $this->getLanguage();
+            $language->load('com_installer', JPATH_ADMINISTRATOR, 'en-GB', false, true);
+            $language->load('com_installer', JPATH_ADMINISTRATOR, null, true);
+
+            Factory::getApplication()->enqueueMessage(Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_UPDATE_NOTICE'), 'warning');
+        }
+
+        $params = ComponentHelper::getParams('com_joomlaupdate');
+
+        switch ($params->get('updatesource', 'default')) {
+            case 'next':
+                // "Minor & Patch Release for Current version AND Next Major Release".
+                $this->langKey         = 'COM_JOOMLAUPDATE_VIEW_DEFAULT_UPDATES_INFO_NEXT';
+                $this->updateSourceKey = Text::_('COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_NEXT');
+                break;
+
+            case 'custom':
+                // "Custom"
+                $this->langKey         = 'COM_JOOMLAUPDATE_VIEW_DEFAULT_UPDATES_INFO_CUSTOM';
+                $this->updateSourceKey = Text::_('COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_CUSTOM');
+                break;
+
+            default:
+                /**
+                 * "Minor & Patch Release for Current version (recommended and default)".
+                 * The commented "case" below are for documenting where 'default' and legacy options falls
+                 * case 'default':
+                 * case 'sts':
+                 * case 'lts':
+                 * case 'nochange':
+                 * case 'testing':
+                 */
+                $this->langKey         = 'COM_JOOMLAUPDATE_VIEW_DEFAULT_UPDATES_INFO_DEFAULT';
+                $this->updateSourceKey = Text::_('COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_DEFAULT');
+        }
+
+        $this->noVersionCheck = $params->get('versioncheck', 1) == 0;
+        $this->noBackupCheck  = $params->get('backupcheck', 1) == 0;
+
+        // Remove temporary files
+        $this->getModel()->removePackageFiles();
+
+        $this->addToolbar();
+
+        // Render the view.
+        parent::display($tpl);
+    }
+
+    /**
+     * Add the page title and toolbar.
+     *
+     * @return  void
+     *
+     * @since   4.0.0
+     */
+    protected function addToolbar()
+    {
+        // Set the toolbar information.
+        ToolbarHelper::title(Text::_('COM_JOOMLAUPDATE_OVERVIEW'), 'joomla install');
+
+        if (\in_array($this->getLayout(), ['update', 'complete'])) {
+            $arrow = $this->getLanguage()->isRtl() ? 'arrow-right' : 'arrow-left';
+
+            ToolbarHelper::link('index.php?option=com_joomlaupdate', 'JTOOLBAR_BACK', $arrow);
+
+            ToolbarHelper::title(Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_TAB_UPLOAD'), 'joomla install');
+        } elseif (!$this->selfUpdateAvailable) {
+            ToolbarHelper::custom('update.purge', 'loop', '', 'COM_JOOMLAUPDATE_TOOLBAR_CHECK', false);
+        }
+
+        // Add toolbar buttons.
+        if ($this->getCurrentUser()->authorise('core.admin')) {
+            ToolbarHelper::preferences('com_joomlaupdate');
+        }
+
+        ToolbarHelper::divider();
+        ToolbarHelper::help('Joomla_Update');
+    }
+
+    /**
+     * Returns true, if the pre update check should be displayed.
+     *
+     * @return boolean
+     *
+     * @since 3.10.0
+     */
+    public function shouldDisplayPreUpdateCheck()
+    {
+        // When the download URL is not found there is no core upgrade path
+        if (!isset($this->updateInfo['object']->downloadurl->_data)) {
+            return false;
+        }
+
+        $nextMinor = Version::MAJOR_VERSION . '.' . (Version::MINOR_VERSION + 1);
+
+        // Show only when we found a download URL, we have an update and when we update to the next minor or greater.
+        return $this->updateInfo['hasUpdate']
+            && version_compare($this->updateInfo['latest'], $nextMinor, '>=');
+    }
+}

administrator/components/com_joomlaupdate/src/View/Update/HtmlView.php

@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2012 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\Component\Joomlaupdate\Administrator\View\Update;
+
+use Joomla\CMS\Factory;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\MVC\View\HtmlView as BaseHtmlView;
+use Joomla\CMS\Toolbar\ToolbarHelper;
+
+// phpcs:disable PSR1.Files.SideEffects
+\defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
+
+/**
+ * Joomla! Update's Update View
+ *
+ * @since  2.5.4
+ */
+class HtmlView extends BaseHtmlView
+{
+    /**
+     * Renders the view.
+     *
+     * @param   string  $tpl  Template name.
+     *
+     * @return  void
+     */
+    public function display($tpl = null)
+    {
+        Factory::getApplication()->getInput()->set('hidemainmenu', true);
+
+        // Set the toolbar information.
+        ToolbarHelper::title(Text::_('COM_JOOMLAUPDATE_OVERVIEW'), 'sync install');
+
+        // Render the view.
+        parent::display($tpl);
+    }
+}

administrator/components/com_joomlaupdate/src/View/Upload/HtmlView.php

@@ -0,0 +1,113 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2016 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\Component\Joomlaupdate\Administrator\View\Upload;
+
+use Joomla\CMS\Component\ComponentHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\MVC\View\HtmlView as BaseHtmlView;
+use Joomla\CMS\Toolbar\ToolbarHelper;
+
+// phpcs:disable PSR1.Files.SideEffects
+\defined('_JEXEC') or die;
+// phpcs:enable PSR1.Files.SideEffects
+
+/**
+ * Joomla! Update's Update View
+ *
+ * @since  3.6.0
+ */
+class HtmlView extends BaseHtmlView
+{
+    /**
+     * An array with the Joomla! update information.
+     *
+     * @var    array
+     *
+     * @since  4.0.0
+     */
+    protected $updateInfo = null;
+
+    /**
+     * Flag if the update component itself has to be updated
+     *
+     * @var boolean  True when update is available otherwise false
+     *
+     * @since 4.0.0
+     */
+    protected $selfUpdateAvailable = false;
+
+    /**
+     * Warnings for the upload update
+     *
+     * @var array  An array of warnings which could prevent the upload update
+     *
+     * @since 4.0.0
+     */
+    protected $warnings = [];
+
+    /**
+     * Should I disable the confirmation checkbox for taking a backup before updating?
+     *
+     * @var   boolean
+     * @since 4.2.0
+     */
+    protected $noBackupCheck = false;
+
+    /**
+     * Renders the view.
+     *
+     * @param   string  $tpl  Template name.
+     *
+     * @return  void
+     *
+     * @since   3.6.0
+     */
+    public function display($tpl = null)
+    {
+        // Load com_installer's language
+        $language = $this->getLanguage();
+        $language->load('com_installer', JPATH_ADMINISTRATOR, 'en-GB', false, true);
+        $language->load('com_installer', JPATH_ADMINISTRATOR, null, true);
+
+        $this->updateInfo          = $this->get('UpdateInformation');
+        $this->selfUpdateAvailable = $this->get('CheckForSelfUpdate');
+
+        if ($this->getLayout() !== 'captive') {
+            $this->warnings = $this->get('Items', 'warnings');
+        }
+
+        $params               = ComponentHelper::getParams('com_joomlaupdate');
+        $this->noBackupCheck  = $params->get('backupcheck', 1) == 0;
+
+        $this->addToolbar();
+
+        // Render the view.
+        parent::display($tpl);
+    }
+
+    /**
+     * Add the page title and toolbar.
+     *
+     * @return  void
+     *
+     * @since   4.0.0
+     */
+    protected function addToolbar()
+    {
+        // Set the toolbar information.
+        ToolbarHelper::title(Text::_('COM_JOOMLAUPDATE_OVERVIEW'), 'sync install');
+
+        $arrow = $this->getLanguage()->isRtl() ? 'arrow-right' : 'arrow-left';
+        ToolbarHelper::link('index.php?option=com_joomlaupdate&' . ($this->getLayout() == 'captive' ? 'view=upload' : ''), 'JTOOLBAR_BACK', $arrow);
+        ToolbarHelper::divider();
+        ToolbarHelper::help('Joomla_Update');
+    }
+}

administrator/components/com_joomlaupdate/tmpl/joomlaupdate/complete.php

@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2012 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\HTML\HTMLHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Router\Route;
+use Joomla\CMS\Uri\Uri;
+
+/** @var \Joomla\Component\Joomlaupdate\Administrator\View\Joomlaupdate\HtmlView $this */
+
+$hadErrors    = $this->state->get('update_finished_with_error');
+$errors       = $this->state->get('update_errors');
+$channelReset = $this->state->get('update_channel_reset');
+$logFile      = $this->state->get('log_file');
+$installerMsg = $this->state->get('installer_message');
+$forumLink    = '<a href="https://forum.joomla.org/" target="_blank" rel="noopener noreferrer">https://forum.joomla.org/</a>';
+
+?>
+<div class="card">
+    <h2 class="card-header"><?php echo Text::_('COM_JOOMLAUPDATE_VIEW_COMPLETE_HEADING'); ?></h2>
+    <div class="card-body">
+        <?php if ($channelReset) : ?>
+            <div class="alert alert-success">
+                <span class="icon-check-circle" aria-hidden="true"></span><span class="visually-hidden"><?php echo Text::_('NOTICE'); ?></span>
+                <?php echo Text::sprintf('COM_JOOMLAUPDATE_UPDATE_CHANGE_UPDATE_SOURCE_OK', Text::_('COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_NEXT'), Text::_('COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_DEFAULT')); ?>
+            </div>
+        <?php elseif ($channelReset !== null) : ?>
+            <div class="alert alert-warning">
+                <span class="icon-check-circle" aria-hidden="true"></span><span class="visually-hidden"><?php echo Text::_('WARNING'); ?></span>
+                <?php echo Text::sprintf('COM_JOOMLAUPDATE_UPDATE_CHANGE_UPDATE_SOURCE_FAILED', Text::_('COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_NEXT'), Text::_('COM_JOOMLAUPDATE_CONFIG_UPDATESOURCE_DEFAULT')); ?>
+            </div>
+        <?php endif; ?>
+        <?php if (!$hadErrors) : ?>
+            <div class="alert alert-success">
+                <span class="icon-check-circle" aria-hidden="true"></span><span class="visually-hidden"><?php echo Text::_('NOTICE'); ?></span>
+                <?php echo Text::sprintf('COM_JOOMLAUPDATE_VIEW_COMPLETE_MESSAGE', '&#x200E;' . JVERSION); ?>
+            </div>
+        <?php else : ?>
+            <div class="alert alert-error">
+                <span class="icon-check-circle" aria-hidden="true"></span><span class="visually-hidden"><?php echo Text::_('NOTICE'); ?></span>
+                <?php echo Text::sprintf('COM_JOOMLAUPDATE_VIEW_COMPLETE_WITH_ERROR_MESSAGE', $logFile, $forumLink); ?>
+            </div>
+            <p>
+                <a href="<?php echo Uri::base(true); ?>/" class="btn btn-primary"><?php echo Text::_('JGLOBAL_TPL_CPANEL_LINK_TEXT') ?></a>
+            </p>
+            <?php if ($errors) : ?>
+                <h3><?php echo Text::_('COM_JOOMLAUPDATE_VIEW_COMPLETE_UPDATE_ERRORS'); ?></h3>
+                <?php foreach ($errors as $error) : ?>
+                    <div class="alert alert-error"><?php echo $error; ?></div>
+                <?php endforeach; ?>
+            <?php endif; ?>
+        <?php endif; ?>
+
+        <?php if ($installerMsg) : ?>
+        <div>
+            <h3><?php echo Text::_('COM_JOOMLAUPDATE_VIEW_COMPLETE_INSTALLER_MESSAGE'); ?></h3>
+            <div class="alert alert-warning"><?php echo $installerMsg ?></div>
+        </div>
+        <?php endif; ?>
+    </div>
+</div>
+
+<form action="<?php echo Route::_('index.php?option=com_joomlaupdate'); ?>" method="post" id="adminForm">
+    <input type="hidden" name="task" value="">
+    <?php echo HTMLHelper::_('form.token'); ?>
+</form>

administrator/components/com_joomlaupdate/tmpl/joomlaupdate/default.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<metadata>
+	<layout title="COM_JOOMLAUPDATE_DEFAULT_VIEW_DEFAULT_TITLE">
+		<message>
+			<![CDATA[COM_JOOMLAUPDATE_DEFAULT_VIEW_DEFAULT_DESC]]>
+		</message>
+	</layout>
+	<fields name="params">
+		<fieldset name="basic" label="JOPTIONS">
+			<field
+				name="ajax-badge"
+				type="radio"
+				label="COM_JOOMLAUPDATE_JOOMLAUPDATE_VIEW_DISPLAY_BADGE"
+				layout="joomla.form.field.radio.switcher"
+				default=""
+				>
+				<option value="">JHIDE</option>
+				<option value="index.php?option=com_joomlaupdate&amp;task=getMenuBadgeData&amp;format=json">JSHOW</option>
+			</field>
+		</fieldset>
+	</fields>
+</metadata>

administrator/components/com_joomlaupdate/tmpl/joomlaupdate/noupdate.php

@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @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\HTML\HTMLHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Layout\LayoutHelper;
+use Joomla\CMS\Session\Session;
+
+/** @var \Joomla\Component\Joomlaupdate\Administrator\View\Joomlaupdate\HtmlView $this */
+
+$uploadLink       = 'index.php?option=com_joomlaupdate&view=upload';
+$reasonNoDownload = '';
+
+if (!empty($this->reasonNoDownload)) {
+    $reasonNoDownload = Text::_($this->reasonNoDownload) . '<br>';
+
+    if (isset($this->detailsNoDownload->php)) {
+        $reasonNoDownload .= Text::sprintf(
+            'COM_JOOMLAUPDATE_NODOWNLOAD_EMPTYSTATE_REASON_PHP',
+            $this->detailsNoDownload->php->used,
+            $this->detailsNoDownload->php->required
+        ) . '<br>';
+    }
+
+    if (isset($this->detailsNoDownload->db)) {
+        $reasonNoDownload .= Text::sprintf(
+            'COM_JOOMLAUPDATE_NODOWNLOAD_EMPTYSTATE_REASON_DATABASE',
+            Text::_('JLIB_DB_SERVER_TYPE_' . $this->detailsNoDownload->db->type),
+            $this->detailsNoDownload->db->used,
+            $this->detailsNoDownload->db->required
+        ) . '<br>';
+    }
+
+    $reasonNoDownload .= Text::_('COM_JOOMLAUPDATE_NODOWNLOAD_EMPTYSTATE_REASON_ACTION') . '<br>';
+}
+
+$displayData = [
+    'textPrefix' => 'COM_JOOMLAUPDATE' . $this->messagePrefix,
+    'content'    => $reasonNoDownload . Text::sprintf($this->langKey, $this->updateSourceKey),
+    'formURL'    => 'index.php?option=com_joomlaupdate&view=joomlaupdate',
+    'helpURL'    => 'https://docs.joomla.org/Special:MyLanguage/Updating_from_an_existing_version',
+    'icon'       => 'icon-loop joomlaupdate',
+    'createURL'  => 'index.php?option=com_joomlaupdate&task=update.purge&' . Session::getFormToken() . '=1'
+];
+
+if ($this->getCurrentUser()->authorise('core.admin', 'com_joomlaupdate')) {
+    $displayData['formAppend'] = '<div class="text-center"><a href="' . $uploadLink . '" class="btn btn-sm btn-outline-secondary">' . Text::_($displayData['textPrefix'] . '_EMPTYSTATE_APPEND') . '</a></div>';
+}
+
+if (isset($this->updateInfo['object']) && isset($this->updateInfo['object']->get('infourl')->_data)) :
+    $displayData['content'] .= '<br>' . HTMLHelper::_(
+        'link',
+        $this->updateInfo['object']->get('infourl')->_data,
+        Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_INFOURL'),
+        [
+            'target' => '_blank',
+            'rel'    => 'noopener noreferrer',
+            'title'  => isset($this->updateInfo['object']->get('infourl')->title) ? Text::sprintf('JBROWSERTARGET_NEW_TITLE', $this->updateInfo['object']->get('infourl')->title) : ''
+        ]
+    );
+endif;
+
+$content = LayoutHelper::render('joomla.content.emptystate', $displayData);
+
+// Inject Joomla! version
+echo str_replace('%1$s', '&#x200E;' . $this->updateInfo['latest'], $content);

administrator/components/com_joomlaupdate/tmpl/joomlaupdate/preupdatecheck.php

@@ -0,0 +1,371 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @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\Factory;
+use Joomla\CMS\HTML\HTMLHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Router\Route;
+use Joomla\CMS\Uri\Uri;
+use Joomla\CMS\Version;
+use Joomla\Component\Joomlaupdate\Administrator\View\Joomlaupdate\HtmlView;
+
+/** @var HtmlView $this */
+
+/** @var \Joomla\CMS\WebAsset\WebAssetManager $wa */
+$wa = $this->getDocument()->getWebAssetManager();
+$wa->useScript('core')
+    ->useScript('com_joomlaupdate.default')
+    ->useScript('bootstrap.popover')
+    ->useScript('bootstrap.tab');
+
+// Text::script doesn't have a sprintf equivalent so work around this
+$this->getDocument()->addScriptOptions('nonCoreCriticalPlugins', $this->nonCoreCriticalPlugins);
+
+// Push Joomla! Update client-side error messages
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_POTENTIALLY_DANGEROUS_PLUGIN_CONFIRM_MESSAGE');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSION_NO_COMPATIBILITY_INFORMATION');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSION_WARNING_UNKNOWN');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSION_SERVER_ERROR');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_SHOW_MORE_COMPATIBILITY_INFORMATION');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_SHOW_LESS_COMPATIBILITY_INFORMATION');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_POTENTIALLY_DANGEROUS_PLUGIN');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_POTENTIALLY_DANGEROUS_PLUGIN_DESC');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_POTENTIALLY_DANGEROUS_PLUGIN_LIST');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_POTENTIALLY_DANGEROUS_PLUGIN_CONFIRM_MESSAGE');
+Text::script('COM_JOOMLAUPDATE_VIEW_DEFAULT_HELP');
+
+// Push Joomla! core Joomla.Request error messages
+Text::script('JLIB_JS_AJAX_ERROR_CONNECTION_ABORT');
+Text::script('JLIB_JS_AJAX_ERROR_NO_CONTENT');
+Text::script('JLIB_JS_AJAX_ERROR_OTHER');
+Text::script('JLIB_JS_AJAX_ERROR_PARSE');
+Text::script('JLIB_JS_AJAX_ERROR_TIMEOUT');
+
+$compatibilityTypes = [
+    'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_RUNNING_PRE_UPDATE_CHECKS' => [
+        'class' => 'info',
+        'icon'  => 'hourglass fa-spin',
+        'notes' => 'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_RUNNING_PRE_UPDATE_CHECKS_NOTES',
+        'group' => 0,
+    ],
+    'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_REQUIRING_UPDATES_TO_BE_COMPATIBLE' => [
+        'class' => 'danger',
+        'icon'  => 'times',
+        'notes' => 'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_REQUIRING_UPDATES_TO_BE_COMPATIBLE_NOTES',
+        'group' => 2,
+    ],
+    'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_PRE_UPDATE_CHECKS_FAILED' => [
+        'class' => 'warning',
+        'icon'  => 'exclamation-triangle',
+        'notes' => 'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_PRE_UPDATE_CHECKS_FAILED_NOTES',
+        'group' => 4,
+    ],
+    'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_UPDATE_SERVER_OFFERS_NO_COMPATIBLE_VERSION' => [
+        'class' => 'warning',
+        'icon'  => 'exclamation-triangle',
+        'notes' => 'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_UPDATE_SERVER_OFFERS_NO_COMPATIBLE_VERSION_NOTES',
+        'group' => 1,
+    ],
+    'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_PROBABLY_COMPATIBLE' => [
+        'class' => 'success',
+        'icon'  => 'check',
+        'notes' => 'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_PROBABLY_COMPATIBLE_NOTES',
+        'group' => 3,
+    ],
+];
+
+$latestJoomlaVersion = $this->updateInfo['latest'];
+$currentJoomlaVersion = $this->updateInfo['installed'] ?? JVERSION;
+
+$updatePossible = true;
+
+if (version_compare($this->updateInfo['latest'], Version::MAJOR_VERSION + 1, '>=') && $this->isDefaultBackendTemplate === false) {
+    Factory::getApplication()->enqueueMessage(
+        Text::sprintf(
+            'COM_JOOMLAUPDATE_VIEW_DEFAULT_NON_CORE_BACKEND_TEMPLATE_USED_NOTICE',
+            ucfirst($this->defaultBackendTemplate)
+        ),
+        'info'
+    );
+}
+?>
+
+<div id="joomlaupdate-wrapper" class="main-card p-3 mt-3" data-joomla-target-version="<?php echo $latestJoomlaVersion; ?>" data-joomla-current-version="<?php echo $currentJoomlaVersion; ?>">
+
+    <h2 class="my-3">
+        <?php echo Text::sprintf('COM_JOOMLAUPDATE_VIEW_DEFAULT_PREUPDATE_CHECK', '&#x200E;' . $this->updateInfo['latest']); ?>
+    </h2>
+    <p>
+        <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXPLANATION_AND_LINK_TO_DOCS'); ?>
+    </p>
+
+    <div class="d-flex flex-wrap flex-lg-nowrap align-items-start my-4" id="preupdatecheck">
+        <div class="nav flex-column text-nowrap nav-pills me-3 mb-4" role="tablist" aria-orientation="vertical">
+            <button class="nav-link d-flex justify-content-between align-items-center active" id="joomlaupdate-precheck-required-tab" data-bs-toggle="pill" data-bs-target="#joomlaupdate-precheck-required-content" type="button" role="tab" aria-controls="joomlaupdate-precheck-required-content" aria-selected="true">
+                <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_REQUIRED_SETTINGS'); ?>
+                <?php $labelClass = 'success'; ?>
+                <?php foreach ($this->phpOptions as $option) : ?>
+                    <?php if (!$option->state) : ?>
+                        <?php $labelClass = 'danger'; ?>
+                        <?php $updatePossible = false; ?>
+                        <?php break; ?>
+                    <?php endif; ?>
+                <?php endforeach; ?>
+                <span class="fa fa-<?php echo $labelClass == 'danger' ? 'times' : 'check'; ?> fa-fw py-1 bg-white text-<?php echo $labelClass; ?>" aria-hidden="true"></span>
+            </button>
+            <button class="nav-link d-flex justify-content-between align-items-center" id="joomlaupdate-precheck-recommended-tab" data-bs-toggle="pill" data-bs-target="#joomlaupdate-precheck-recommended-content" type="button" role="tab" aria-controls="joomlaupdate-precheck-recommended-content" aria-selected="false">
+                <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_RECOMMENDED_SETTINGS'); ?>
+                <?php $labelClass = 'success'; ?>
+                <?php foreach ($this->phpSettings as $setting) : ?>
+                    <?php if ($setting->state !== $setting->recommended) : ?>
+                        <?php $labelClass = 'warning'; ?>
+                        <?php break; ?>
+                    <?php endif; ?>
+                <?php endforeach; ?>
+                <span class="fa fa-<?php echo $labelClass == 'warning' ? 'exclamation-triangle' : 'check'; ?> fa-fw py-1 bg-white text-<?php echo $labelClass; ?>" aria-hidden="true"></span>
+            </button>
+            <button class="nav-link d-flex justify-content-between align-items-center" id="joomlaupdate-precheck-extensions-tab" data-bs-toggle="pill" data-bs-target="#joomlaupdate-precheck-extensions-content" type="button" role="tab" aria-controls="joomlaupdate-precheck-extensions-content" aria-selected="false">
+                <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_EXTENSIONS'); ?>
+                <?php $labelClass = 'success'; ?>
+                <span class="fa fa-spinner fa-spin fa-fw py-1" aria-hidden="true"></span>
+            </button>
+        </div>
+
+        <div class="tab-content w-100">
+            <div class="tab-pane fade show active" id="joomlaupdate-precheck-required-content" role="tabpanel" aria-labelledby="joomlaupdate-precheck-required-tab">
+                <h3>
+                    <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_REQUIRED_SETTINGS'); ?>
+                </h3>
+                <div class="table-responsive">
+                    <table class="table table-striped" id="preupdatecheck">
+                        <caption class="visually-hidden">
+                            <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_CHECK_CAPTION'); ?>
+                        </caption>
+                        <thead>
+                            <tr>
+                                <th scope="col">
+                                    <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_HEADING_REQUIREMENT'); ?>
+                                </th>
+                                <th scope="col">
+                                    <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_HEADING_CHECKED'); ?>
+                                </th>
+                            </tr>
+                        </thead>
+                        <tbody>
+                        <?php foreach ($this->phpOptions as $option) : ?>
+                            <tr>
+                                <th scope="row">
+                                    <?php echo $option->label; ?>
+                                    <?php if ($option->notice) : ?>
+                                    <div class="small">
+                                        <?php echo $option->notice; ?>
+                                    </div>
+                                    <?php endif; ?>
+                                </th>
+                                <td>
+                                    <span class="badge bg-<?php echo $option->state ? 'success' : 'danger'; ?>">
+                                        <?php echo Text::_($option->state ? 'JYES' : 'JNO'); ?>
+                                    </span>
+                                </td>
+                            </tr>
+                        <?php endforeach; ?>
+                        </tbody>
+                    </table>
+                </div>
+            </div>
+            <div class="tab-pane fade show" id="joomlaupdate-precheck-recommended-content" role="tabpanel" aria-labelledby="joomlaupdate-precheck-recommended-tab">
+                <h3>
+                    <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_RECOMMENDED_SETTINGS'); ?>
+                </h3>
+                <div class="table-responsive">
+                    <table class="table table-striped" id="preupdatecheckphp">
+                        <caption>
+                            <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_RECOMMENDED_SETTINGS_DESC'); ?>
+                        </caption>
+                        <thead>
+                            <tr>
+                                <th scope="col">
+                                    <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_DIRECTIVE'); ?>
+                                </th>
+                                <th scope="col">
+                                    <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_RECOMMENDED'); ?>
+                                </th>
+                                <th scope="col">
+                                    <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_ACTUAL'); ?>
+                                </th>
+                            </tr>
+                        </thead>
+                        <tbody>
+                            <?php foreach ($this->phpSettings as $setting) : ?>
+                                <tr>
+                                    <th scope="row">
+                                        <?php echo $setting->label; ?>
+                                    </th>
+                                    <td>
+                                        <?php echo Text::_($setting->recommended ? 'JON' : 'JOFF'); ?>
+                                    </td>
+                                    <td>
+                                        <span class="badge bg-<?php echo ($setting->state === $setting->recommended) ? 'success' : 'warning'; ?>">
+                                            <?php echo Text::_($setting->state ? 'JON' : 'JOFF'); ?>
+                                        </span>
+                                    </td>
+                                </tr>
+                            <?php endforeach; ?>
+                        </tbody>
+                    </table>
+                </div>
+            </div>
+            <div class="tab-pane fade show" id="joomlaupdate-precheck-extensions-content" role="tabpanel" aria-labelledby="joomlaupdate-precheck-extensions-tab">
+                <h3>
+                    <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS'); ?>
+                </h3>
+                <div id="preupdateCheckWarning">
+                    <div class="alert alert-warning">
+                        <h4 class="alert-heading">
+                            <?php echo Text::_('WARNING'); ?>
+                        </h4>
+                        <div class="alert-message">
+                            <div class="preupdateCheckIncomplete">
+                                <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_CHECK_NOT_COMPLETE'); ?>
+                            </div>
+                        </div>
+                    </div>
+                </div>
+
+                <div id="preupdateCheckCompleteProblems" class="hidden">
+                    <div class="alert alert-warning">
+                        <h4 class="alert-heading">
+                            <?php echo Text::_('WARNING'); ?>
+                        </h4>
+                        <div class="alert-message">
+                            <div class="preupdateCheckComplete">
+                                <?php echo Text::_('COM_JOOMLAUPDATE_PREUPDATE_CHECK_COMPLETED_YOU_HAVE_DANGEROUS_PLUGINS'); ?>
+                            </div>
+                        </div>
+                    </div>
+                </div>
+
+            <?php if (!empty($this->nonCoreExtensions)) : ?>
+                <div class="w-100">
+                    <?php foreach ($compatibilityTypes as $compatibilityType => $data) : ?>
+                    <div class="<?php echo $data['group'] > 0 ? 'hidden' : ''; ?> compatibilityTable" id="compatibilityTable<?php echo (int) $data['group']; ?>">
+                        <h4 class="text-<?php echo $data['class']; ?> align-items-center">
+                            <span class="fa fa-<?php echo $data['icon']; ?> me-2"></span>
+                            <?php echo Text::_($compatibilityType); ?>
+                            <?php if ($data['group'] > 0) : ?>
+                                <button type="button" class="btn btn-primary btn-sm ms-3 compatibilitytoggle" data-state="closed">
+                                    <?php echo Text::_(
+                                        'COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_SHOW_MORE_COMPATIBILITY_INFORMATION'
+                                    ); ?>
+                                </button>
+                            <?php endif; ?>
+                        </h4>
+
+                        <div class="table-responsive mb-5">
+                            <table class="table table-striped">
+                                <caption>
+                                <?php echo Text::_($data['notes']); ?>
+                                </caption>
+                                <thead class="row-fluid">
+                                    <tr>
+                                        <th class="exname" scope="col">
+                                            <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSION_NAME'); ?>
+                                        </th>
+                                        <th class="extype" scope="col">
+                                            <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSION_TYPE'); ?>
+                                        </th>
+                                        <th class="instver hidden" scope="col">
+                                            <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSION_INSTALLED_VERSION'); ?>
+                                        </th>
+                                        <th class="currcomp hidden" scope="col">
+                                            <?php echo Text::sprintf('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSION_COMPATIBLE_WITH_JOOMLA_VERSION', isset($this->updateInfo['installed']) ? $this->escape($this->updateInfo['installed']) : JVERSION); ?>
+                                        </th>
+                                        <th class="upcomp hidden" scope="col">
+                                            <?php echo Text::sprintf('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSION_COMPATIBLE_WITH_JOOMLA_VERSION', $this->escape($this->updateInfo['latest'])); ?>
+                                        </th>
+                                    </tr>
+                                </thead>
+                                <tbody class="row-fluid">
+                                <?php // Only include this row once since the javascript moves the results into the right place ?>
+                                <?php if ($data['group'] == 0) : ?>
+                                    <?php foreach ($this->nonCoreExtensions as $extension) : ?>
+                                        <tr>
+                                            <th class="exname" scope="row">
+                                                <?php echo $extension->name; ?>
+                                            </th>
+                                            <td class="extype">
+                                                <?php echo Text::_('COM_INSTALLER_TYPE_' . strtoupper($extension->type)); ?>
+                                            </td>
+                                            <td class="instver hidden">
+                                                <?php echo $extension->version; ?>
+                                            </td>
+                                            <td id="available-version-<?php echo $extension->extension_id; ?>" class="currcomp hidden"></td>
+                                            <td id="preUpdateCheck_<?php echo $extension->extension_id; ?>"
+                                                class="extension-check upcomp hidden"
+                                                data-extension-id="<?php echo $extension->extension_id; ?>"
+                                                data-extension-current-version="<?php echo $extension->version; ?>"
+                                            >
+                                                <img src="<?php echo Uri::root(true); ?>/media/system/images/ajax-loader.gif">
+                                            </td>
+                                        </tr>
+                                    <?php endforeach; ?>
+                                <?php endif; ?>
+                                </tbody>
+                            </table>
+                        </div>
+                    </div>
+                    <?php endforeach; ?>
+                </div>
+            <?php else : ?>
+                <div class="alert alert-info">
+                    <span class="icon-info-circle" aria-hidden="true"></span><span class="visually-hidden"><?php echo Text::_('INFO'); ?></span>
+                    <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_NONE'); ?>
+                </div>
+            <?php endif; ?>
+            </div>
+        </div>
+    </div>
+
+    <?php if ($updatePossible) : ?>
+    <form action="<?php echo Route::_('index.php?option=com_joomlaupdate&layout=update'); ?>" method="post" class="d-flex flex-column mb-5">
+
+        <?php if (!$this->noVersionCheck) : ?>
+        <div id="preupdatecheckbox">
+            <div class="form-check d-flex justify-content-center mb-3">
+                <input type="checkbox" class="form-check-input me-3" id="noncoreplugins" name="noncoreplugins" value="1" required />
+                <label class="form-check-label" for="noncoreplugins">
+                    <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_NON_CORE_PLUGIN_CONFIRMATION'); ?>
+                </label>
+            </div>
+        </div>
+        <?php endif; ?>
+
+        <button class="btn btn-lg btn-warning <?php echo $this->noVersionCheck ? '' : 'disabled' ?> submitupdate mx-auto"
+                type="submit" <?php echo $this->noVersionCheck ? '' : 'disabled' ?>>
+            <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_INSTALLUPDATE'); ?>
+        </button>
+    </form>
+    <?php endif; ?>
+
+    <form action="<?php echo Route::_('index.php?option=com_joomlaupdate&layout=update'); ?>" method="post" name="adminForm" id="adminForm">
+        <input type="hidden" name="task" value="">
+        <?php echo HTMLHelper::_('form.token'); ?>
+    </form>
+
+    <?php if ($this->getCurrentUser()->authorise('core.admin')) : ?>
+        <div class="text-center">
+            <a href="<?php echo Route::_('index.php?option=com_joomlaupdate&view=upload'); ?>" class="btn btn-sm btn-outline-secondary">
+                <?php echo Text::_('COM_JOOMLAUPDATE_EMPTYSTATE_APPEND'); ?>
+            </a>
+        </div>
+    <?php endif; ?>
+</div>

administrator/components/com_joomlaupdate/tmpl/joomlaupdate/reinstall.php

@@ -0,0 +1,57 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @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\HTML\HTMLHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Layout\LayoutHelper;
+
+/** @var \Joomla\Component\Joomlaupdate\Administrator\View\Joomlaupdate\HtmlView $this */
+
+/** @var \Joomla\CMS\WebAsset\WebAssetManager $wa */
+$wa = $this->getDocument()->getWebAssetManager();
+$wa->useScript('core')
+    ->useScript('com_joomlaupdate.default')
+    ->useScript('bootstrap.popover');
+
+$uploadLink = 'index.php?option=com_joomlaupdate&view=upload';
+
+$displayData = [
+    'textPrefix' => 'COM_JOOMLAUPDATE_REINSTALL',
+    'content'    => Text::sprintf($this->langKey, $this->updateSourceKey),
+    'formURL'    => 'index.php?option=com_joomlaupdate&view=joomlaupdate',
+    'helpURL'    => 'https://docs.joomla.org/Special:MyLanguage/Updating_from_an_existing_version',
+    'icon'       => 'icon-loop joomlaupdate',
+    'createURL'  => '#'
+];
+
+if (isset($this->updateInfo['object']) && isset($this->updateInfo['object']->get('infourl')->_data)) :
+    $displayData['content'] .= '<br>' . HTMLHelper::_(
+        'link',
+        $this->updateInfo['object']->get('infourl')->_data,
+        Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_INFOURL'),
+        [
+            'target' => '_blank',
+            'rel'    => 'noopener noreferrer',
+            'title'  => isset($this->updateInfo['object']->get('infourl')->title) ? Text::sprintf('JBROWSERTARGET_NEW_TITLE', $this->updateInfo['object']->get('infourl')->title) : ''
+        ]
+    );
+endif;
+
+if ($this->getCurrentUser()->authorise('core.admin', 'com_joomlaupdate')) :
+    $displayData['formAppend'] = '<div class="text-center"><a href="' . $uploadLink . '" class="btn btn-sm btn-outline-secondary">' . Text::_('COM_JOOMLAUPDATE_EMPTYSTATE_APPEND') . '</a></div>';
+endif;
+
+echo '<div id="joomlaupdate-wrapper">';
+
+echo LayoutHelper::render('joomla.content.emptystate', $displayData);
+
+echo '</div>';

administrator/components/com_joomlaupdate/tmpl/joomlaupdate/selfupdate.php

@@ -0,0 +1,23 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @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\Layout\LayoutHelper;
+
+$displayData = [
+    'textPrefix' => 'COM_JOOMLAUPDATE_SELF',
+    'formURL'    => 'index.php?option=com_joomlaupdate&view=joomlaupdate',
+    'helpURL'    => 'https://docs.joomla.org/Special:MyLanguage/Updating_from_an_existing_version',
+    'icon'       => 'icon-loop joomlaupdate',
+    'createURL'  => 'index.php?option=com_installer&view=update'
+];
+
+echo LayoutHelper::render('joomla.content.emptystate', $displayData);

administrator/components/com_joomlaupdate/tmpl/joomlaupdate/update.php

@@ -0,0 +1,71 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @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\HTML\HTMLHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Layout\LayoutHelper;
+
+/** @var \Joomla\Component\Joomlaupdate\Administrator\View\Joomlaupdate\HtmlView $this */
+
+/** @var \Joomla\CMS\WebAsset\WebAssetManager $wa */
+$wa = $this->getDocument()->getWebAssetManager();
+$wa->useScript('core')
+    ->useScript('com_joomlaupdate.default')
+    ->useScript('bootstrap.popover');
+
+$uploadLink = 'index.php?option=com_joomlaupdate&view=upload';
+
+$displayData = [
+    'textPrefix' => 'COM_JOOMLAUPDATE_UPDATE',
+    'title'      => Text::sprintf('COM_JOOMLAUPDATE_UPDATE_EMPTYSTATE_TITLE', $this->escape($this->updateInfo['latest'])),
+    'content'    => Text::sprintf($this->langKey, $this->updateSourceKey),
+    'formURL'    => 'index.php?option=com_joomlaupdate&view=joomlaupdate',
+    'helpURL'    => 'https://docs.joomla.org/Special:MyLanguage/Updating_from_an_existing_version',
+    'icon'       => 'icon-loop joomlaupdate',
+    'createURL'  => '#'
+];
+
+if (isset($this->updateInfo['object']) && isset($this->updateInfo['object']->get('infourl')->_data)) :
+    $displayData['content'] .= '<br>' . HTMLHelper::_(
+        'link',
+        $this->updateInfo['object']->get('infourl')->_data,
+        Text::_('COM_JOOMLAUPDATE_VIEW_DEFAULT_INFOURL'),
+        [
+            'target' => '_blank',
+            'rel'    => 'noopener noreferrer',
+            'title'  => isset($this->updateInfo['object']->get('infourl')->title) ? Text::sprintf('JBROWSERTARGET_NEW_TITLE', $this->updateInfo['object']->get('infourl')->title) : ''
+        ]
+    );
+endif;
+
+// Confirm backup and check
+$classVisibility = $this->noBackupCheck ? 'd-none' : '';
+$checked = $this->noBackupCheck ? 'checked' : '';
+$displayData['content'] .= '<div class="form-check d-flex justify-content-center ' . $classVisibility . '">
+		<input class="form-check-input me-2" type="checkbox" value="" id="joomlaupdate-confirm-backup" ' . $checked . '>
+		<label class="form-check-label" for="joomlaupdate-confirm-backup">
+		' . Text::_('COM_JOOMLAUPDATE_UPDATE_CONFIRM_BACKUP') . '
+		</label>
+	</div>';
+
+if ($this->getCurrentUser()->authorise('core.admin', 'com_joomlaupdate')) :
+    $displayData['formAppend'] = '
+        <div class="text-center"><a href="' . $uploadLink . '" class="btn btn-sm btn-outline-secondary">' . Text::_('COM_JOOMLAUPDATE_EMPTYSTATE_APPEND') . '</a></div>
+        <input type="hidden" name="targetVersion" value="' . $this->updateInfo['latest'] . '" />
+    ';
+endif;
+
+echo '<div id="joomlaupdate-wrapper">';
+
+echo LayoutHelper::render('joomla.content.emptystate', $displayData);
+
+echo '</div>';

administrator/components/com_joomlaupdate/tmpl/update/default.php

@@ -0,0 +1,137 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2012 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\Factory;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Router\Route;
+use Joomla\CMS\Uri\Uri;
+
+/** @var \Joomla\Component\Joomlaupdate\Administrator\View\Update\HtmlView $this */
+
+/** @var Joomla\CMS\WebAsset\WebAssetManager $wa */
+$wa = $this->getDocument()->getWebAssetManager();
+$wa->useScript('core')
+    ->useScript('com_joomlaupdate.admin-update')
+    ->useScript('bootstrap.modal');
+
+Text::script('COM_JOOMLAUPDATE_ERRORMODAL_HEAD_FORBIDDEN');
+Text::script('COM_JOOMLAUPDATE_ERRORMODAL_BODY_FORBIDDEN');
+Text::script('COM_JOOMLAUPDATE_ERRORMODAL_HEAD_SERVERERROR');
+Text::script('COM_JOOMLAUPDATE_ERRORMODAL_BODY_SERVERERROR');
+Text::script('COM_JOOMLAUPDATE_ERRORMODAL_HEAD_GENERIC');
+Text::script('COM_JOOMLAUPDATE_ERRORMODAL_BODY_INVALIDLOGIN');
+Text::script('COM_JOOMLAUPDATE_UPDATING_FAIL');
+Text::script('COM_JOOMLAUPDATE_UPDATING_COMPLETE');
+Text::script('COM_JOOMLAUPDATE_VIEW_UPDATE_ITEMS');
+Text::script('JLIB_SIZE_BYTES');
+Text::script('JLIB_SIZE_KB');
+Text::script('JLIB_SIZE_MB');
+Text::script('JLIB_SIZE_GB');
+Text::script('JLIB_SIZE_TB');
+Text::script('JLIB_SIZE_PB');
+Text::script('JLIB_SIZE_EB');
+Text::script('JLIB_SIZE_ZB');
+Text::script('JLIB_SIZE_YB');
+
+$password = Factory::getApplication()->getUserState('com_joomlaupdate.password', null);
+$filesize = Factory::getApplication()->getUserState('com_joomlaupdate.filesize', null);
+$ajaxUrl = Uri::base() . 'components/com_joomlaupdate/extract.php';
+$returnUrl = 'index.php?option=com_joomlaupdate&task=update.finalise&' . Factory::getSession()->getFormToken() . '=1';
+
+$this->getDocument()->addScriptOptions(
+    'joomlaupdate',
+    [
+        'password' => $password,
+        'totalsize' => $filesize,
+        'ajax_url' => $ajaxUrl,
+        'return_url' => $returnUrl,
+    ]
+);
+
+$helpUrl = 'https://docs.joomla.org/Special:MyLanguage/J4.x:Joomla_Update_Problems';
+?>
+
+<div class="px-4 py-5 my-5 text-center" id="joomlaupdate-progress">
+    <span class="fa-8x mb-4 icon-loop joomlaupdate" aria-hidden="true"></span>
+    <h1 class="display-5 fw-bold"><?php echo Text::_('COM_JOOMLAUPDATE_UPDATING_HEAD') ?></h1>
+    <div class="col-lg-6 mx-auto">
+        <p class="lead mb-4" id="update-title">
+            <?php echo Text::_('COM_JOOMLAUPDATE_UPDATING_INPROGRESS'); ?>
+        </p>
+        <div id="progress" class="progress my-3">
+            <div id="progress-bar" class="progress-bar progress-bar-striped progress-bar-animated"
+                 aria-valuenow="0" aria-valuemin="0" aria-valuemax="100">
+            </div>
+        </div>
+        <div id="update-progress" class="container text-muted my-3">
+            <div class="row">
+                <div class="col">
+                    <span class="fa fa-file-archive" aria-hidden="true"></span>
+                    <span class="visually-hidden"><?php echo Text::_('COM_JOOMLAUPDATE_VIEW_UPDATE_BYTESREAD'); ?></span>
+                    <span id="extbytesin"></span>
+                </div>
+                <div class="col">
+                    <span class="fa fa-hdd" aria-hidden="true"></span>
+                    <span class="visually-hidden"><?php echo Text::_('COM_JOOMLAUPDATE_VIEW_UPDATE_BYTESEXTRACTED'); ?></span>
+                    <span id="extbytesout"></span>
+                </div>
+                <div class="col">
+                    <span class="fa fa-copy" aria-hidden="true"></span>
+                    <span class="visually-hidden"><?php echo Text::_('COM_JOOMLAUPDATE_VIEW_UPDATE_FILESEXTRACTED'); ?></span>
+                    <span id="extfiles"></span>
+                </div>
+            </div>
+        </div>
+    </div>
+</div>
+
+<div class="px-4 d-none" id="joomlaupdate-error">
+    <div class="card border-danger">
+        <h1 class="card-header bg-danger text-white" id="errorDialogLabel"></h1>
+        <div class="card-body">
+            <div id="errorDialogMessage"></div>
+        </div>
+        <div class="card-footer">
+            <div class="d-flex flex-row flex-wrap gap-2 align-items-center">
+                <div>
+                    <a href="<?php echo $helpUrl ?>"
+                       target="_blank"
+                       class="btn btn-info">
+                        <span class="fa fa-info-circle" aria-hidden="true"></span>
+                        <?php echo Text::_('COM_JOOMLAUPDATE_ERRORMODAL_BTN_HELP') ?>
+                    </a>
+                </div>
+                <div>
+                    <button type="button" id="joomlaupdate-resume"
+                            class="btn btn-primary">
+                        <span class="fa fa-play" aria-hidden="true"></span>
+                        <?php echo Text::_('COM_JOOMLAUPDATE_ERRORSTATE_BTN_RETRY') ?>
+                    </button>
+                </div>
+                <div>
+                    <button type="button" id="joomlaupdate-restart"
+                            class="btn btn-warning">
+                        <span class="fa fa-redo" aria-hidden="true"></span>
+                        <?php echo Text::_('COM_JOOMLAUPDATE_ERRORSTATE_BTN_RESTART') ?>
+                    </button>
+                </div>
+                <div class="flex-grow-1"></div>
+                <div>
+                    <a href="<?php echo Route::_('index.php?option=com_joomlaupdate') ?>"
+                       class="btn btn-danger btn-sm ms-3">
+                        <?php echo Text::_('JCANCEL') ?>
+                    </a>
+                </div>
+            </div>
+        </div>
+    </div>
+</div>

administrator/components/com_joomlaupdate/tmpl/update/finaliseconfirm.php

@@ -0,0 +1,83 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2016 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\Factory;
+use Joomla\CMS\HTML\HTMLHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Router\Route;
+
+/** @var \Joomla\Component\Joomlaupdate\Administrator\View\Update\HtmlView $this */
+
+/** @var Joomla\CMS\WebAsset\WebAssetManager $wa */
+$wa = $this->getDocument()->getWebAssetManager();
+$wa->useScript('keepalive');
+
+?>
+
+<div class="alert warning">
+    <h4 class="alert-heading">
+        <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_UPDATE_FINALISE_HEAD'); ?>
+    </h4>
+    <p>
+        <?php echo Text::sprintf('COM_JOOMLAUPDATE_VIEW_UPDATE_FINALISE_HEAD_DESC', Factory::getApplication()->get('sitename')); ?>
+    </p>
+</div>
+
+<hr>
+
+<form action="<?php echo Route::_('index.php', true); ?>" method="post" id="form-login" class="d-flex justify-content-center text-center">
+    <fieldset class="loginform">
+        <legend><?php echo Text::_('COM_JOOMLAUPDATE_CONFIRM'); ?></legend>
+        <div class="control-group">
+            <div class="controls">
+                <div class="input-group">
+                    <input name="username" id="mod-login-username" type="text" class="form-control" required="required" autocomplete="username" placeholder="<?php echo Text::_('JGLOBAL_USERNAME'); ?>" size="15" autofocus="true">
+                    <span class="input-group-text">
+                        <span class="icon-user" aria-hidden="true"></span>
+                        <label for="mod-login-username" class="visually-hidden">
+                            <?php echo Text::_('JGLOBAL_USERNAME'); ?>
+                        </label>
+                    </span>
+                </div>
+            </div>
+        </div>
+        <div class="control-group">
+            <div class="controls">
+                <div class="input-group">
+                    <input name="passwd" id="mod-login-password" type="password" class="form-control" required="required" autocomplete="current-password" placeholder="<?php echo Text::_('JGLOBAL_PASSWORD'); ?>" size="15">
+                    <span class="input-group-text">
+                        <span class="icon-lock" aria-hidden="true"></span>
+                        <label for="mod-login-password" class="visually-hidden">
+                            <?php echo Text::_('JGLOBAL_PASSWORD'); ?>
+                        </label>
+                    </span>
+                </div>
+            </div>
+        </div>
+        <div class="control-group">
+            <div class="controls">
+                <div class="btn-group">
+                    <a class="btn btn-danger" href="index.php?option=com_joomlaupdate">
+                        <span class="icon-times" aria-hidden="true"></span> <?php echo Text::_('JCANCEL'); ?>
+                    </a>
+                    <button type="submit" class="btn btn-primary">
+                        <span class="icon-play" aria-hidden="true"></span> <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_UPDATE_FINALISE_CONFIRM_AND_CONTINUE'); ?>
+                    </button>
+                </div>
+            </div>
+        </div>
+
+        <input type="hidden" name="option" value="com_joomlaupdate">
+        <input type="hidden" name="task" value="update.finaliseconfirm">
+        <?php echo HTMLHelper::_('form.token'); ?>
+    </fieldset>
+</form>

administrator/components/com_joomlaupdate/tmpl/upload/captive.php

@@ -0,0 +1,85 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @copyright   (C) 2016 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\Factory;
+use Joomla\CMS\HTML\HTMLHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Router\Route;
+
+/** @var \Joomla\Component\Joomlaupdate\Administrator\View\Upload\HtmlView $this */
+
+/** @var Joomla\CMS\WebAsset\WebAssetManager $wa */
+$wa = $this->getDocument()->getWebAssetManager();
+$wa->useScript('core')
+    ->useScript('jquery')
+    ->useScript('form.validate')
+    ->useScript('keepalive')
+    ->useScript('field.passwordview');
+
+Text::script('JSHOWPASSWORD');
+Text::script('JHIDEPASSWORD');
+?>
+
+<div class="alert alert-warning">
+    <h4 class="alert-heading">
+        <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_UPLOAD_CAPTIVE_INTRO_HEAD'); ?>
+    </h4>
+    <p>
+        <?php echo Text::sprintf('COM_JOOMLAUPDATE_VIEW_UPLOAD_CAPTIVE_INTRO_BODY', Factory::getApplication()->get('sitename')); ?>
+    </p>
+</div>
+
+<hr>
+
+<form action="<?php echo Route::_('index.php', true); ?>" method="post" id="form-login" class="text-center card">
+    <fieldset class="loginform card-body">
+        <legend class="h2 mb-3"><?php echo Text::_('COM_JOOMLAUPDATE_CAPTIVE_HEADLINE'); ?></legend>
+        <div class="control-group">
+            <div class="controls">
+                <div class="input-group">
+                    <input name="username" id="mod-login-username" type="text" class="form-control" required="required" autocomplete="username" placeholder="<?php echo Text::_('JGLOBAL_USERNAME'); ?>" size="15" autofocus="true">
+                    <span class="input-group-text">
+                        <span class="icon-user icon-fw" aria-hidden="true"></span>
+                        <label for="mod-login-username" class="visually-hidden">
+                            <?php echo Text::_('JGLOBAL_USERNAME'); ?>
+                        </label>
+                    </span>
+                </div>
+            </div>
+        </div>
+        <div class="control-group">
+            <div class="controls">
+                <div class="input-group">
+                    <input name="passwd" id="mod-login-password" type="password" class="form-control" required="required" autocomplete="current-password" placeholder="<?php echo Text::_('JGLOBAL_PASSWORD'); ?>" size="15">
+                    <button type="button" class="btn btn-secondary input-password-toggle">
+                        <span class="icon-eye icon-fw" aria-hidden="true"></span>
+                        <span class="visually-hidden"><?php echo Text::_('JSHOWPASSWORD'); ?></span>
+                    </button>
+                </div>
+            </div>
+        </div>
+        <div class="control-group">
+            <div class="controls">
+                <a class="btn btn-danger" href="index.php?option=com_joomlaupdate">
+                    <span class="icon-times icon-white" aria-hidden="true"></span> <?php echo Text::_('JCANCEL'); ?>
+                </a>
+                <button type="submit" class="btn btn-primary">
+                    <span class="icon-play icon-white" aria-hidden="true"></span> <?php echo Text::_('COM_INSTALLER_INSTALL_BUTTON'); ?>
+                </button>
+            </div>
+        </div>
+
+        <input type="hidden" name="option" value="com_joomlaupdate">
+        <input type="hidden" name="task" value="update.confirm">
+        <?php echo HTMLHelper::_('form.token'); ?>
+    </fieldset>
+</form>

administrator/components/com_joomlaupdate/tmpl/upload/default.php

@@ -0,0 +1,102 @@
+<?php
+
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_joomlaupdate
+ *
+ * @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\HTML\HTMLHelper;
+use Joomla\CMS\Language\Text;
+use Joomla\CMS\Updater\Update;
+use Joomla\CMS\Utility\Utility;
+use Joomla\Component\Joomlaupdate\Administrator\View\Joomlaupdate\HtmlView;
+
+/** @var HtmlView $this */
+
+/** @var \Joomla\CMS\WebAsset\WebAssetManager $wa */
+$wa = $this->getDocument()->getWebAssetManager();
+$wa->useScript('core')
+    ->useScript('com_joomlaupdate.default')
+    ->useScript('bootstrap.popover');
+
+Text::script('COM_INSTALLER_MSG_INSTALL_PLEASE_SELECT_A_PACKAGE', true);
+Text::script('COM_INSTALLER_MSG_WARNINGS_UPLOADFILETOOBIG', true);
+Text::script('JGLOBAL_SELECTED_UPLOAD_FILE_SIZE', true);
+
+$latestJoomlaVersion = $this->updateInfo['latest'];
+$currentJoomlaVersion = $this->updateInfo['installed'] ?? JVERSION;
+?>
+
+<div id="joomlaupdate-wrapper" class="main-card mt-3 p-3" data-joomla-target-version="<?php echo $latestJoomlaVersion; ?>" data-joomla-current-version="<?php echo $currentJoomlaVersion; ?>">
+<div class="alert alert-info">
+    <span class="icon-info-circle" aria-hidden="true"></span><span class="visually-hidden"><?php echo Text::_('INFO'); ?></span>
+    <?php echo Text::sprintf('COM_JOOMLAUPDATE_VIEW_DEFAULT_UPLOAD_INTRO', 'https://downloads.joomla.org/latest'); ?>
+    <?php if (is_object($this->updateInfo['object']) && ($this->updateInfo['object'] instanceof Update)) : ?>
+        <br><br>
+        <span class="icon-info-circle" aria-hidden="true"></span><span class="visually-hidden"><?php echo Text::_('INFO'); ?></span>
+        <?php echo Text::sprintf('COM_JOOMLAUPDATE_VIEW_DEFAULT_PACKAGE_INFO', $this->updateInfo['object']->downloadurl->_data); ?>
+    <?php endif; ?>
+</div>
+
+<?php if (count($this->warnings)) : ?>
+    <h3><?php echo Text::_('COM_INSTALLER_SUBMENU_WARNINGS'); ?></h3>
+    <?php foreach ($this->warnings as $warning) : ?>
+        <div class="alert alert-warning">
+            <h4 class="alert-heading">
+                <span class="icon-exclamation-triangle" aria-hidden="true"></span>
+                <span class="visually-hidden"><?php echo Text::_('WARNING'); ?></span>
+                <?php echo $warning['message']; ?>
+            </h4>
+            <p class="mb-0"><?php echo $warning['description']; ?></p>
+        </div>
+    <?php endforeach; ?>
+    <div class="alert alert-info">
+        <h4 class="alert-heading">
+            <span class="icon-info-circle" aria-hidden="true"></span>
+            <span class="visually-hidden"><?php echo Text::_('INFO'); ?></span>
+            <?php echo Text::_('COM_INSTALLER_MSG_WARNINGFURTHERINFO'); ?>
+        </h4>
+        <p class="mb-0"><?php echo Text::_('COM_INSTALLER_MSG_WARNINGFURTHERINFODESC'); ?></p>
+    </div>
+<?php endif; ?>
+
+<form enctype="multipart/form-data" action="index.php" method="post" id="uploadForm">
+
+    <div class="mb-3">
+        <label for="install_package" class="form-label">
+            <?php echo Text::_('COM_JOOMLAUPDATE_VIEW_UPLOAD_PACKAGE_FILE'); ?>
+        </label>
+
+        <input class="form-control" type="file" id="install_package" name="install_package" accept=".zip,application/zip">
+        <?php $maxSizeBytes = Utility::getMaxUploadSize(); ?>
+        <?php $maxSize = HTMLHelper::_('number.bytes', $maxSizeBytes); ?>
+        <input id="max_upload_size" name="max_upload_size" type="hidden" value="<?php echo $maxSizeBytes; ?>"/>
+        <div class="form-text"><?php echo Text::sprintf('JGLOBAL_MAXIMUM_UPLOAD_SIZE_LIMIT', '&#x200E;' . $maxSize); ?></div>
+        <div class="form-text hidden" id="file_size"><?php echo Text::sprintf('JGLOBAL_SELECTED_UPLOAD_FILE_SIZE', '&#x200E;' . ''); ?></div>
+        <div class="alert alert-warning hidden" id="max_upload_size_warn">
+            <?php echo Text::_('COM_INSTALLER_MSG_WARNINGS_UPLOADFILETOOBIG'); ?>
+        </div>
+    </div>
+
+    <div class="form-check mb-3 <?php echo $this->noBackupCheck ? 'd-none' : '' ?>">
+        <input class="form-check-input me-2 <?php echo $this->noBackupCheck ? 'd-none' : '' ?>"
+               type="checkbox" disabled value="" id="joomlaupdate-confirm-backup"
+                <?php echo $this->noBackupCheck ? 'checked' : '' ?>>
+        <label class="form-check-label" for="joomlaupdate-confirm-backup">
+            <?php echo Text::_('COM_JOOMLAUPDATE_UPDATE_CONFIRM_BACKUP'); ?>
+        </label>
+    </div>
+
+    <button id="uploadButton" class="btn btn-primary" disabled type="button"><?php echo Text::_('COM_INSTALLER_UPLOAD_AND_INSTALL'); ?></button>
+
+    <input type="hidden" name="task" value="update.upload">
+    <input type="hidden" name="option" value="com_joomlaupdate">
+    <?php echo HTMLHelper::_('form.token'); ?>
+
+</form>
+</div>