ProfileTranslationHandler.php

<?php

namespace Drupal\user;

use Drupal\Core\Entity\EntityInterface;
use Drupal\content_translation\ContentTranslationHandler;
use Drupal\Core\Form\FormStateInterface;

/**
 * Defines the translation handler for users.
 */
class ProfileTranslationHandler extends ContentTranslationHandler {
    
    /**
     * {@inheritdoc}
     */
    protected function hasPublishedStatus() {
        // User status has nothing to do with translations visibility.
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function hasCreatedTime() {
        // User creation date has nothing to do with translation creation date.
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function entityFormAlter(array &$form, FormStateInterface $form_state, EntityInterface $entity) {
        parent::entityFormAlter($form, $form_state, $entity);
        $form['actions']['submit']['#submit'][] = [
            $this,
            'entityFormSave',
        ];
    }
    
    /**
     * Form submission handler for ProfileTranslationHandler::entityFormAlter().
     *
     * This handles the save action.
     *
     * @see \Drupal\Core\Entity\EntityForm::build()
     */
    public function entityFormSave(array $form, FormStateInterface $form_state) {
        if ($this->getSourceLangcode($form_state)) {
            $entity = $form_state->getFormObject()
                ->getEntity();
            // We need a redirect here, otherwise we would get an access denied page
            // since the current URL would be preserved and we would try to add a
            // translation for a language that already has a translation.
            $form_state->setRedirectUrl($entity->toUrl());
        }
    }

}