Build a new taxonomy hierarchy widget with parents as field labels

src/Plugin/Field/FieldWidget/TaxonomyLabelHierarchyWidget.php

@@ -0,0 +1,136 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\stanford_fields\Plugin\Field\FieldWidget;
+
+use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\Field\Attribute\FieldWidget;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\Plugin\Field\FieldWidget\OptionsWidgetBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\Element;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\cshs\Component\CshsOption;
+use Drupal\cshs\Element\CshsElement;
+
+/**
+ * Defines the 'taxonomy_label_hierarchy' field widget.
+ */
+#[FieldWidget(
+ id: 'taxonomy_label_hierarchy',
+ label: new TranslatableMarkup('Taxonomy Label Hierarchy'),
+ field_types: ['entity_reference'],
+ multiple_values: TRUE,
+)]
+final class TaxonomyLabelHierarchyWidget extends OptionsWidgetBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state): array {
+ $element = parent::formElement($items, $delta, $element, $form, $form_state);
+ $options = $this->getOptions($items->getEntity());
+ $selected_items = $this->getSelectedOptions($items);
+
+ $element += [
+ '#type' => 'fieldset',
+ '#tree' => TRUE,
+ ];
+
+ $grouped_options = [];
+ foreach ($options as $id => $option) {
+ if (!str_starts_with((string) $option, '-')) {
+ $parent = (string) $option;
+ continue;
+ }
+ $grouped_options[$parent][$id] = substr((string) $option, 1);
+ }
+
+ foreach ($grouped_options as $group_label => $group_options) {
+ $key = preg_replace('@[^a-z0-9_.]+@', '_', mb_strtolower($group_label));
+ foreach ($group_options as $tid => &$option) {
+ /** @var \Drupal\taxonomy\TermInterface $term */
+ $term = \Drupal::entityTypeManager()
+ ->getStorage('taxonomy_term')
+ ->load($tid);
+ $option = new CshsOption(ltrim($option, "-"), $term->get('parent')
+ ->getString(), $group_label);
+ }
+
+ $num_values = $form_state->get($key);
+ $default_values = array_values(array_intersect($selected_items, array_keys($group_options)));
+
+ if (!$num_values) {
+ $num_values = max(1, count($default_values));
+ $form_state->set($key, $num_values);
+ }
+
+ $element[$key] = [
+ '#type' => 'fieldset',
+ '#title' => $group_label,
+ '#prefix' => '<div id="' . $key . '">',
+ '#suffix' => '</div>',
+ ];
+
+ for ($i = 0; $i < $num_values; $i++) {
+ $element[$key][$i]['target_id'] = [
+ '#type' => CshsElement::ID,
+ '#labels' => [],
+ '#options' => $group_options,
+ '#multiple' => $this->multiple,
+ '#default_value' => $default_values[$i] ?? NULL,
+ ];
+ }
+ $element[$key]['add'] = [
+ '#type' => 'submit',
+ '#value' => $this->t('Add More'),
+ '#name' => $key,
+ '#submit' => [[self::class, 'addOne']],
+ '#ajax' => [
+ 'callback' => [self::class, 'addMoreCallback'],
+ 'wrapper' => $key,
+ ],
+ ];
+ }
+
+ return $element;
+ }
+
+ /**
+ * Ajax callback to add another.
+ */
+ public static function addMoreCallback(array &$form, FormStateInterface $form_state) {
+ $trigger = $form_state->getTriggeringElement();
+ $path = $trigger['#array_parents'];
+ array_pop($path);
+ return NestedArray::getValue($form, $path);
+ }
+
+ /**
+ * Form callback to add another.
+ */
+ public static function addOne(array &$form, FormStateInterface $form_state) {
+ $trigger = $form_state->getTriggeringElement();
+ $name = $trigger['#name'];
+ $form_state->set($name, $form_state->get($name) + 1);
+ $form_state->setRebuild();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function validateElement(array $element, FormStateInterface $form_state) {
+ $value = [];
+ foreach (Element::children($element) as $key) {
+ foreach (Element::children($element[$key]) as $delta) {
+ if (isset($element[$key][$delta]['target_id']['#value']) && is_array($element[$key][$delta]['target_id']['#value'])) {
+ $value[] = end($element[$key][$delta]['target_id']['#value']);
+ }
+ }
+ }
+ $element['#value'] = array_filter(array_unique($value));
+ parent::validateElement($element, $form_state);
+ }
+
+}