--- /dev/null
+<?php
+
+namespace Drupal\search\Form;
+
+use Drupal\Core\Entity\EntityForm;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\PluginFormInterface;
+use Drupal\search\SearchPageRepositoryInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides a base form for search pages.
+ */
+abstract class SearchPageFormBase extends EntityForm {
+
+ /**
+ * The entity being used by this form.
+ *
+ * @var \Drupal\search\SearchPageInterface
+ */
+ protected $entity;
+
+ /**
+ * The search plugin being configured.
+ *
+ * @var \Drupal\search\Plugin\SearchInterface
+ */
+ protected $plugin;
+
+ /**
+ * The search page repository.
+ *
+ * @var \Drupal\search\SearchPageRepositoryInterface
+ */
+ protected $searchPageRepository;
+
+ /**
+ * Constructs a new search form.
+ *
+ * @param \Drupal\search\SearchPageRepositoryInterface $search_page_repository
+ * The search page repository.
+ */
+ public function __construct(SearchPageRepositoryInterface $search_page_repository) {
+ $this->searchPageRepository = $search_page_repository;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function create(ContainerInterface $container) {
+ return new static(
+ $container->get('search.search_page_repository')
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getBaseFormId() {
+ return 'search_entity_form';
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildForm(array $form, FormStateInterface $form_state) {
+ $this->plugin = $this->entity->getPlugin();
+ return parent::buildForm($form, $form_state);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function form(array $form, FormStateInterface $form_state) {
+ $form['label'] = [
+ '#type' => 'textfield',
+ '#title' => $this->t('Label'),
+ '#description' => $this->t('The label for this search page.'),
+ '#default_value' => $this->entity->label(),
+ '#maxlength' => '255',
+ ];
+
+ $form['id'] = [
+ '#type' => 'machine_name',
+ '#default_value' => $this->entity->id(),
+ '#disabled' => !$this->entity->isNew(),
+ '#maxlength' => 64,
+ '#machine_name' => [
+ 'exists' => [$this, 'exists'],
+ ],
+ ];
+ $form['path'] = [
+ '#type' => 'textfield',
+ '#title' => $this->t('Path'),
+ '#field_prefix' => 'search/',
+ '#default_value' => $this->entity->getPath(),
+ '#maxlength' => '255',
+ '#required' => TRUE,
+ ];
+ $form['plugin'] = [
+ '#type' => 'value',
+ '#value' => $this->entity->get('plugin'),
+ ];
+
+ if ($this->plugin instanceof PluginFormInterface) {
+ $form += $this->plugin->buildConfigurationForm($form, $form_state);
+ }
+
+ return parent::form($form, $form_state);
+ }
+
+ /**
+ * Determines if the search page entity already exists.
+ *
+ * @param string $id
+ * The search configuration ID.
+ *
+ * @return bool
+ * TRUE if the search configuration exists, FALSE otherwise.
+ */
+ public function exists($id) {
+ $entity = $this->entityTypeManager->getStorage('search_page')->getQuery()
+ ->condition('id', $id)
+ ->execute();
+ return (bool) $entity;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function validateForm(array &$form, FormStateInterface $form_state) {
+ parent::validateForm($form, $form_state);
+
+ // Ensure each path is unique.
+ $path = $this->entityTypeManager->getStorage('search_page')->getQuery()
+ ->condition('path', $form_state->getValue('path'))
+ ->condition('id', $form_state->getValue('id'), '<>')
+ ->execute();
+ if ($path) {
+ $form_state->setErrorByName('path', $this->t('The search page path must be unique.'));
+ }
+
+ if ($this->plugin instanceof PluginFormInterface) {
+ $this->plugin->validateConfigurationForm($form, $form_state);
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function submitForm(array &$form, FormStateInterface $form_state) {
+ parent::submitForm($form, $form_state);
+
+ if ($this->plugin instanceof PluginFormInterface) {
+ $this->plugin->submitConfigurationForm($form, $form_state);
+ }
+ return $this->entity;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function save(array $form, FormStateInterface $form_state) {
+ $this->entity->save();
+
+ $form_state->setRedirectUrl($this->entity->urlInfo('collection'));
+ }
+
+}