LocaleController.php

<?php

namespace Drupal\locale\Controller;

use Drupal\Core\Controller\ControllerBase;

/**
 * Return response for manual check translations.
 */
class LocaleController extends ControllerBase {
    
    /**
     * Checks for translation updates and displays the translations status.
     *
     * Manually checks the translation status without the use of cron.
     *
     * @return \Symfony\Component\HttpFoundation\RedirectResponse
     *   A redirection to translations reports page.
     */
    public function checkTranslation() {
        $this->moduleHandler()
            ->loadInclude('locale', 'inc', 'locale.compare');
        // Check translation status of all translatable project in all languages.
        // First we clear the cached list of projects. Although not strictly
        // necessary, this is helpful in case the project list is out of sync.
        locale_translation_flush_projects();
        locale_translation_check_projects();
        // Execute a batch if required. A batch is only used when remote files
        // are checked.
        if (batch_get()) {
            return batch_process('admin/reports/translations');
        }
        return $this->redirect('locale.translate_status');
    }
    
    /**
     * Shows the string search screen.
     *
     * @return array
     *   The render array for the string search screen.
     */
    public function translatePage() {
        return [
            'filter' => $this->formBuilder()
                ->getForm('Drupal\\locale\\Form\\TranslateFilterForm'),
            'form' => $this->formBuilder()
                ->getForm('Drupal\\locale\\Form\\TranslateEditForm'),
        ];
    }

}