--- /dev/null
+<?php
+
+namespace Drupal\taxonomy;
+
+use Drupal\Core\Entity\ContentEntityForm;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Base for handler for taxonomy term edit forms.
+ */
+class TermForm extends ContentEntityForm {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function form(array $form, FormStateInterface $form_state) {
+ $term = $this->entity;
+ $vocab_storage = $this->entityManager->getStorage('taxonomy_vocabulary');
+ $taxonomy_storage = $this->entityManager->getStorage('taxonomy_term');
+ $vocabulary = $vocab_storage->load($term->bundle());
+
+ $parent = array_keys($taxonomy_storage->loadParents($term->id()));
+ $form_state->set(['taxonomy', 'parent'], $parent);
+ $form_state->set(['taxonomy', 'vocabulary'], $vocabulary);
+
+ $form['relations'] = [
+ '#type' => 'details',
+ '#title' => $this->t('Relations'),
+ '#open' => $vocabulary->getHierarchy() == VocabularyInterface::HIERARCHY_MULTIPLE,
+ '#weight' => 10,
+ ];
+
+ // \Drupal\taxonomy\TermStorageInterface::loadTree() and
+ // \Drupal\taxonomy\TermStorageInterface::loadParents() may contain large
+ // numbers of items so we check for taxonomy.settings:override_selector
+ // before loading the full vocabulary. Contrib modules can then intercept
+ // before hook_form_alter to provide scalable alternatives.
+ if (!$this->config('taxonomy.settings')->get('override_selector')) {
+ $parent = array_keys($taxonomy_storage->loadParents($term->id()));
+ $children = $taxonomy_storage->loadTree($vocabulary->id(), $term->id());
+
+ // A term can't be the child of itself, nor of its children.
+ foreach ($children as $child) {
+ $exclude[] = $child->tid;
+ }
+ $exclude[] = $term->id();
+
+ $tree = $taxonomy_storage->loadTree($vocabulary->id());
+ $options = ['<' . $this->t('root') . '>'];
+ if (empty($parent)) {
+ $parent = [0];
+ }
+
+ foreach ($tree as $item) {
+ if (!in_array($item->tid, $exclude)) {
+ $options[$item->tid] = str_repeat('-', $item->depth) . $item->name;
+ }
+ }
+
+ $form['relations']['parent'] = [
+ '#type' => 'select',
+ '#title' => $this->t('Parent terms'),
+ '#options' => $options,
+ '#default_value' => $parent,
+ '#multiple' => TRUE,
+ ];
+ }
+
+ $form['relations']['weight'] = [
+ '#type' => 'textfield',
+ '#title' => $this->t('Weight'),
+ '#size' => 6,
+ '#default_value' => $term->getWeight(),
+ '#description' => $this->t('Terms are displayed in ascending order by weight.'),
+ '#required' => TRUE,
+ ];
+
+ $form['vid'] = [
+ '#type' => 'value',
+ '#value' => $vocabulary->id(),
+ ];
+
+ $form['tid'] = [
+ '#type' => 'value',
+ '#value' => $term->id(),
+ ];
+
+ return parent::form($form, $form_state, $term);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function validateForm(array &$form, FormStateInterface $form_state) {
+ parent::validateForm($form, $form_state);
+
+ // Ensure numeric values.
+ if ($form_state->hasValue('weight') && !is_numeric($form_state->getValue('weight'))) {
+ $form_state->setErrorByName('weight', $this->t('Weight value must be numeric.'));
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildEntity(array $form, FormStateInterface $form_state) {
+ $term = parent::buildEntity($form, $form_state);
+
+ // Prevent leading and trailing spaces in term names.
+ $term->setName(trim($term->getName()));
+
+ // Assign parents with proper delta values starting from 0.
+ $term->parent = array_keys($form_state->getValue('parent'));
+
+ return $term;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function save(array $form, FormStateInterface $form_state) {
+ $term = $this->entity;
+
+ $result = $term->save();
+
+ $edit_link = $term->link($this->t('Edit'), 'edit-form');
+ $view_link = $term->link($term->getName());
+ switch ($result) {
+ case SAVED_NEW:
+ drupal_set_message($this->t('Created new term %term.', ['%term' => $view_link]));
+ $this->logger('taxonomy')->notice('Created new term %term.', ['%term' => $term->getName(), 'link' => $edit_link]);
+ break;
+ case SAVED_UPDATED:
+ drupal_set_message($this->t('Updated term %term.', ['%term' => $view_link]));
+ $this->logger('taxonomy')->notice('Updated term %term.', ['%term' => $term->getName(), 'link' => $edit_link]);
+ break;
+ }
+
+ $current_parent_count = count($form_state->getValue('parent'));
+ $previous_parent_count = count($form_state->get(['taxonomy', 'parent']));
+ // Root doesn't count if it's the only parent.
+ if ($current_parent_count == 1 && $form_state->hasValue(['parent', 0])) {
+ $current_parent_count = 0;
+ $form_state->setValue('parent', []);
+ }
+
+ // If the number of parents has been reduced to one or none, do a check on the
+ // parents of every term in the vocabulary value.
+ $vocabulary = $form_state->get(['taxonomy', 'vocabulary']);
+ if ($current_parent_count < $previous_parent_count && $current_parent_count < 2) {
+ taxonomy_check_vocabulary_hierarchy($vocabulary, $form_state->getValues());
+ }
+ // If we've increased the number of parents and this is a single or flat
+ // hierarchy, update the vocabulary immediately.
+ elseif ($current_parent_count > $previous_parent_count && $vocabulary->getHierarchy() != VocabularyInterface::HIERARCHY_MULTIPLE) {
+ $vocabulary->setHierarchy($current_parent_count == 1 ? VocabularyInterface::HIERARCHY_SINGLE : VocabularyInterface::HIERARCHY_MULTIPLE);
+ $vocabulary->save();
+ }
+
+ $form_state->setValue('tid', $term->id());
+ $form_state->set('tid', $term->id());
+ }
+
+}