class ModulesUninstallForm

class ModulesUninstallForm extends FormBase {
    
    /**
     * The module handler service.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected $moduleHandler;
    
    /**
     * The module installer service.
     *
     * @var \Drupal\Core\Extension\ModuleInstallerInterface
     */
    protected $moduleInstaller;
    
    /**
     * The expirable key value store.
     *
     * @var \Drupal\Core\KeyValueStore\KeyValueStoreExpirableInterface
     */
    protected $keyValueExpirable;
    
    /**
     * The module extension list.
     *
     * @var \Drupal\Core\Extension\ModuleExtensionList
     */
    protected $moduleExtensionList;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('module_handler'), $container->get('module_installer'), $container->get('keyvalue.expirable')
            ->get('modules_uninstall'), $container->get('extension.list.module'));
    }
    
    /**
     * Constructs a ModulesUninstallForm object.
     *
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler.
     * @param \Drupal\Core\Extension\ModuleInstallerInterface $module_installer
     *   The module installer.
     * @param \Drupal\Core\KeyValueStore\KeyValueStoreExpirableInterface $key_value_expirable
     *   The key value expirable factory.
     * @param \Drupal\Core\Extension\ModuleExtensionList $extension_list_module
     *   The module extension list.
     */
    public function __construct(ModuleHandlerInterface $module_handler, ModuleInstallerInterface $module_installer, KeyValueStoreExpirableInterface $key_value_expirable, ModuleExtensionList $extension_list_module) {
        $this->moduleExtensionList = $extension_list_module;
        $this->moduleHandler = $module_handler;
        $this->moduleInstaller = $module_installer;
        $this->keyValueExpirable = $key_value_expirable;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'system_modules_uninstall';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        // Make sure the install API is available.
        include_once DRUPAL_ROOT . '/core/includes/install.inc';
        // Get a list of all available modules that can be uninstalled.
        $uninstallable = array_filter($this->moduleExtensionList
            ->getList(), function ($module) {
            return empty($module->info['required']) && $module->status;
        });
        // Include system.admin.inc so we can use the sort callbacks.
        $this->moduleHandler
            ->loadInclude('system', 'inc', 'system.admin');
        $form['filters'] = [
            '#type' => 'container',
            '#attributes' => [
                'class' => [
                    'table-filter',
                    'js-show',
                ],
            ],
        ];
        $form['filters']['text'] = [
            '#type' => 'search',
            '#title' => $this->t('Filter modules'),
            '#title_display' => 'invisible',
            '#size' => 30,
            '#placeholder' => $this->t('Filter by name or description'),
            '#description' => $this->t('Enter a part of the module name or description'),
            '#attributes' => [
                'class' => [
                    'table-filter-text',
                ],
                'data-table' => '#system-modules-uninstall',
                'autocomplete' => 'off',
            ],
        ];
        $form['modules'] = [];
        // Only build the rest of the form if there are any modules available to
        // uninstall;
        if (empty($uninstallable)) {
            return $form;
        }
        // Sort all modules by their name.
        uasort($uninstallable, 'system_sort_modules_by_info_name');
        $validation_reasons = $this->moduleInstaller
            ->validateUninstall(array_keys($uninstallable));
        $form['uninstall'] = [
            '#tree' => TRUE,
        ];
        foreach ($uninstallable as $module_key => $module) {
            $name = $module->info['name'] ?: $module->getName();
            $form['modules'][$module->getName()]['#module_name'] = $name;
            $form['modules'][$module->getName()]['name']['#markup'] = $name;
            $form['modules'][$module->getName()]['description']['#markup'] = $this->t($module->info['description']);
            $form['uninstall'][$module->getName()] = [
                '#type' => 'checkbox',
                '#title' => $this->t('Uninstall @module module', [
                    '@module' => $name,
                ]),
                '#title_display' => 'invisible',
            ];
            // If a validator returns reasons not to uninstall a module,
            // list the reasons and disable the check box.
            if (isset($validation_reasons[$module_key])) {
                $form['modules'][$module->getName()]['#validation_reasons'] = $validation_reasons[$module_key];
                $form['uninstall'][$module->getName()]['#disabled'] = TRUE;
            }
            // All modules which depend on this one must be uninstalled first, before
            // we can allow this module to be uninstalled.
            foreach (array_keys($module->required_by) as $dependent) {
                if (drupal_get_installed_schema_version($dependent) != SCHEMA_UNINSTALLED) {
                    $name = isset($modules[$dependent]->info['name']) ? $modules[$dependent]->info['name'] : $dependent;
                    $form['modules'][$module->getName()]['#required_by'][] = $name;
                    $form['uninstall'][$module->getName()]['#disabled'] = TRUE;
                }
            }
        }
        $form['#attached']['library'][] = 'system/drupal.system.modules';
        $form['actions'] = [
            '#type' => 'actions',
        ];
        $form['actions']['submit'] = [
            '#type' => 'submit',
            '#value' => $this->t('Uninstall'),
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function validateForm(array &$form, FormStateInterface $form_state) {
        // Form submitted, but no modules selected.
        if (!array_filter($form_state->getValue('uninstall'))) {
            $form_state->setErrorByName('', $this->t('No modules selected.'));
            $form_state->setRedirect('system.modules_uninstall');
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        // Save all the values in an expirable key value store.
        $modules = $form_state->getValue('uninstall');
        $uninstall = array_keys(array_filter($modules));
        $account = $this->currentUser()
            ->id();
        // Store the values for 6 hours. This expiration time is also used in
        // the form cache.
        $this->keyValueExpirable
            ->setWithExpire($account, $uninstall, 6 * 60 * 60);
        // Redirect to the confirm form.
        $form_state->setRedirect('system.modules_uninstall_confirm');
    }

}