--- /dev/null
+<?php
+
+namespace Drupal\form_test\Form;
+
+use Drupal\Core\Form\FormBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Language\LanguageInterface;
+use Symfony\Component\HttpFoundation\JsonResponse;
+
+/**
+ * Builds a form to test the language select form element.
+ */
+class FormTestLanguageSelectForm extends FormBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getFormId() {
+ return 'form_test_language_select';
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildForm(array $form, FormStateInterface $form_state) {
+ $form['languages_all'] = [
+ '#title' => t('Languages: All'),
+ '#type' => 'language_select',
+ '#languages' => LanguageInterface::STATE_ALL,
+ '#default_value' => 'xx',
+ ];
+ $form['languages_configurable'] = [
+ '#title' => t('Languages: Configurable'),
+ '#type' => 'language_select',
+ '#languages' => LanguageInterface::STATE_CONFIGURABLE,
+ '#default_value' => 'en',
+ ];
+ $form['languages_locked'] = [
+ '#title' => t('Languages: Locked'),
+ '#type' => 'language_select',
+ '#languages' => LanguageInterface::STATE_LOCKED,
+ ];
+ $form['languages_config_and_locked'] = [
+ '#title' => t('Languages: Configurable and locked'),
+ '#type' => 'language_select',
+ '#languages' => LanguageInterface::STATE_CONFIGURABLE | LanguageInterface::STATE_LOCKED,
+ '#default_value' => 'dummy_value',
+ ];
+ $form['language_custom_options'] = [
+ '#title' => t('Languages: Custom'),
+ '#type' => 'language_select',
+ '#languages' => LanguageInterface::STATE_CONFIGURABLE | LanguageInterface::STATE_LOCKED,
+ '#options' => ['opt1' => 'First option', 'opt2' => 'Second option', 'opt3' => 'Third option'],
+ '#default_value' => 'opt2',
+ ];
+
+ $form['submit'] = ['#type' => 'submit', '#value' => 'Submit'];
+ return $form;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function submitForm(array &$form, FormStateInterface $form_state) {
+ $form_state->setResponse(new JsonResponse($form_state->getValues()));
+ }
+
+}