--- /dev/null
+<?php
+
+namespace Drupal\taxonomy\Plugin\views\argument;
+
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\views\Plugin\views\argument\ArgumentPluginBase;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Argument handler for taxonomy terms with depth.
+ *
+ * This handler is actually part of the node table and has some restrictions,
+ * because it uses a subquery to find nodes with.
+ *
+ * @ingroup views_argument_handlers
+ *
+ * @ViewsArgument("taxonomy_index_tid_depth")
+ */
+class IndexTidDepth extends ArgumentPluginBase implements ContainerFactoryPluginInterface {
+
+ /**
+ * @var EntityStorageInterface
+ */
+ protected $termStorage;
+
+ /**
+ * {@inheritdoc}
+ */
+ public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityStorageInterface $termStorage) {
+ parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+ $this->termStorage = $termStorage;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+ return new static($configuration, $plugin_id, $plugin_definition, $container->get('entity.manager')->getStorage('taxonomy_term'));
+ }
+
+ protected function defineOptions() {
+ $options = parent::defineOptions();
+
+ $options['depth'] = ['default' => 0];
+ $options['break_phrase'] = ['default' => FALSE];
+ $options['use_taxonomy_term_path'] = ['default' => FALSE];
+
+ return $options;
+ }
+
+ public function buildOptionsForm(&$form, FormStateInterface $form_state) {
+ $form['depth'] = [
+ '#type' => 'weight',
+ '#title' => $this->t('Depth'),
+ '#default_value' => $this->options['depth'],
+ '#description' => $this->t('The depth will match nodes tagged with terms in the hierarchy. For example, if you have the term "fruit" and a child term "apple", with a depth of 1 (or higher) then filtering for the term "fruit" will get nodes that are tagged with "apple" as well as "fruit". If negative, the reverse is true; searching for "apple" will also pick up nodes tagged with "fruit" if depth is -1 (or lower).'),
+ ];
+
+ $form['break_phrase'] = [
+ '#type' => 'checkbox',
+ '#title' => $this->t('Allow multiple values'),
+ '#description' => $this->t('If selected, users can enter multiple values in the form of 1+2+3. Due to the number of JOINs it would require, AND will be treated as OR with this filter.'),
+ '#default_value' => !empty($this->options['break_phrase']),
+ ];
+
+ parent::buildOptionsForm($form, $form_state);
+ }
+
+ /**
+ * Override defaultActions() to remove summary actions.
+ */
+ protected function defaultActions($which = NULL) {
+ if ($which) {
+ if (in_array($which, ['ignore', 'not found', 'empty', 'default'])) {
+ return parent::defaultActions($which);
+ }
+ return;
+ }
+ $actions = parent::defaultActions();
+ unset($actions['summary asc']);
+ unset($actions['summary desc']);
+ unset($actions['summary asc by count']);
+ unset($actions['summary desc by count']);
+ return $actions;
+ }
+
+ public function query($group_by = FALSE) {
+ $this->ensureMyTable();
+
+ if (!empty($this->options['break_phrase'])) {
+ $break = static::breakString($this->argument);
+ if ($break->value === [-1]) {
+ return FALSE;
+ }
+
+ $operator = (count($break->value) > 1) ? 'IN' : '=';
+ $tids = $break->value;
+ }
+ else {
+ $operator = "=";
+ $tids = $this->argument;
+ }
+ // Now build the subqueries.
+ $subquery = db_select('taxonomy_index', 'tn');
+ $subquery->addField('tn', 'nid');
+ $where = db_or()->condition('tn.tid', $tids, $operator);
+ $last = "tn";
+
+ if ($this->options['depth'] > 0) {
+ $subquery->leftJoin('taxonomy_term_hierarchy', 'th', "th.tid = tn.tid");
+ $last = "th";
+ foreach (range(1, abs($this->options['depth'])) as $count) {
+ $subquery->leftJoin('taxonomy_term_hierarchy', "th$count", "$last.parent = th$count.tid");
+ $where->condition("th$count.tid", $tids, $operator);
+ $last = "th$count";
+ }
+ }
+ elseif ($this->options['depth'] < 0) {
+ foreach (range(1, abs($this->options['depth'])) as $count) {
+ $subquery->leftJoin('taxonomy_term_hierarchy', "th$count", "$last.tid = th$count.parent");
+ $where->condition("th$count.tid", $tids, $operator);
+ $last = "th$count";
+ }
+ }
+
+ $subquery->condition($where);
+ $this->query->addWhere(0, "$this->tableAlias.$this->realField", $subquery, 'IN');
+ }
+
+ public function title() {
+ $term = $this->termStorage->load($this->argument);
+ if (!empty($term)) {
+ return $term->getName();
+ }
+ // TODO review text
+ return $this->t('No name');
+ }
+
+}