View source  
  <?php
namespace Drupal\taxonomy\Plugin\views\filter;
use Drupal\Core\Entity\Element\EntityAutocomplete;
use Drupal\Core\Form\FormStateInterface;
use Drupal\taxonomy\Entity\Term;
use Drupal\taxonomy\TermStorageInterface;
use Drupal\taxonomy\VocabularyStorageInterface;
use Drupal\views\ViewExecutable;
use Drupal\views\Plugin\views\display\DisplayPluginBase;
use Drupal\views\Plugin\views\filter\ManyToOne;
use Symfony\Component\DependencyInjection\ContainerInterface;
class TaxonomyIndexTid extends ManyToOne {
  
  var $validated_exposed_input = NULL;
  
  protected $vocabularyStorage;
  
  protected $termStorage;
  
  public function __construct(array $configuration, $plugin_id, $plugin_definition, VocabularyStorageInterface $vocabulary_storage, TermStorageInterface $term_storage) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->vocabularyStorage = $vocabulary_storage;
    $this->termStorage = $term_storage;
  }
  
  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_vocabulary'), $container
      ->get('entity.manager')
      ->getStorage('taxonomy_term'));
  }
  
  public function init(ViewExecutable $view, DisplayPluginBase $display, array &$options = NULL) {
    parent::init($view, $display, $options);
    if (!empty($this->definition['vocabulary'])) {
      $this->options['vid'] = $this->definition['vocabulary'];
    }
  }
  public function hasExtraOptions() {
    return TRUE;
  }
  public function getValueOptions() {
    
  }
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['type'] = array(
      'default' => 'textfield',
    );
    $options['limit'] = array(
      'default' => TRUE,
    );
    $options['vid'] = array(
      'default' => '',
    );
    $options['hierarchy'] = array(
      'default' => FALSE,
    );
    $options['error_message'] = array(
      'default' => TRUE,
    );
    return $options;
  }
  public function buildExtraOptionsForm(&$form, FormStateInterface $form_state) {
    $vocabularies = $this->vocabularyStorage
      ->loadMultiple();
    $options = array();
    foreach ($vocabularies as $voc) {
      $options[$voc
        ->id()] = $voc
        ->label();
    }
    if ($this->options['limit']) {
      
      if (empty($this->options['vid'])) {
        $first_vocabulary = reset($vocabularies);
        $this->options['vid'] = $first_vocabulary
          ->id();
      }
      if (empty($this->definition['vocabulary'])) {
        $form['vid'] = array(
          '#type' => 'radios',
          '#title' => $this
            ->t('Vocabulary'),
          '#options' => $options,
          '#description' => $this
            ->t('Select which vocabulary to show terms for in the regular options.'),
          '#default_value' => $this->options['vid'],
        );
      }
    }
    $form['type'] = array(
      '#type' => 'radios',
      '#title' => $this
        ->t('Selection type'),
      '#options' => array(
        'select' => $this
          ->t('Dropdown'),
        'textfield' => $this
          ->t('Autocomplete'),
      ),
      '#default_value' => $this->options['type'],
    );
    $form['hierarchy'] = array(
      '#type' => 'checkbox',
      '#title' => $this
        ->t('Show hierarchy in dropdown'),
      '#default_value' => !empty($this->options['hierarchy']),
      '#states' => array(
        'visible' => array(
          ':input[name="options[type]"]' => array(
            'value' => 'select',
          ),
        ),
      ),
    );
  }
  protected function valueForm(&$form, FormStateInterface $form_state) {
    $vocabulary = $this->vocabularyStorage
      ->load($this->options['vid']);
    if (empty($vocabulary) && $this->options['limit']) {
      $form['markup'] = array(
        '#markup' => '<div class="js-form-item form-item">' . $this
          ->t('An invalid vocabulary is selected. Please change it in the options.') . '</div>',
      );
      return;
    }
    if ($this->options['type'] == 'textfield') {
      $terms = $this->value ? Term::loadMultiple($this->value) : array();
      $form['value'] = array(
        '#title' => $this->options['limit'] ? $this
          ->t('Select terms from vocabulary @voc', array(
          '@voc' => $vocabulary
            ->label(),
        )) : $this
          ->t('Select terms'),
        '#type' => 'textfield',
        '#default_value' => EntityAutocomplete::getEntityLabels($terms),
      );
      if ($this->options['limit']) {
        $form['value']['#type'] = 'entity_autocomplete';
        $form['value']['#target_type'] = 'taxonomy_term';
        $form['value']['#selection_settings']['target_bundles'] = array(
          $vocabulary
            ->id(),
        );
        $form['value']['#tags'] = TRUE;
        $form['value']['#process_default_value'] = FALSE;
      }
    }
    else {
      if (!empty($this->options['hierarchy']) && $this->options['limit']) {
        $tree = $this->termStorage
          ->loadTree($vocabulary
          ->id(), 0, NULL, TRUE);
        $options = array();
        if ($tree) {
          foreach ($tree as $term) {
            $choice = new \stdClass();
            $choice->option = array(
              $term
                ->id() => str_repeat('-', $term->depth) . \Drupal::entityManager()
                ->getTranslationFromContext($term)
                ->label(),
            );
            $options[] = $choice;
          }
        }
      }
      else {
        $options = array();
        $query = \Drupal::entityQuery('taxonomy_term')
          ->sort('weight')
          ->sort('name')
          ->addTag('term_access');
        if ($this->options['limit']) {
          $query
            ->condition('vid', $vocabulary
            ->id());
        }
        $terms = Term::loadMultiple($query
          ->execute());
        foreach ($terms as $term) {
          $options[$term
            ->id()] = \Drupal::entityManager()
            ->getTranslationFromContext($term)
            ->label();
        }
      }
      $default_value = (array) $this->value;
      if ($exposed = $form_state
        ->get('exposed')) {
        $identifier = $this->options['expose']['identifier'];
        if (!empty($this->options['expose']['reduce'])) {
          $options = $this
            ->reduceValueOptions($options);
          if (!empty($this->options['expose']['multiple']) && empty($this->options['expose']['required'])) {
            $default_value = array();
          }
        }
        if (empty($this->options['expose']['multiple'])) {
          if (empty($this->options['expose']['required']) && (empty($default_value) || !empty($this->options['expose']['reduce']))) {
            $default_value = 'All';
          }
          elseif (empty($default_value)) {
            $keys = array_keys($options);
            $default_value = array_shift($keys);
          }
          elseif ($default_value == array(
            '',
          )) {
            $default_value = 'All';
          }
          else {
            $copy = $default_value;
            $default_value = array_shift($copy);
          }
        }
      }
      $form['value'] = array(
        '#type' => 'select',
        '#title' => $this->options['limit'] ? $this
          ->t('Select terms from vocabulary @voc', array(
          '@voc' => $vocabulary
            ->label(),
        )) : $this
          ->t('Select terms'),
        '#multiple' => TRUE,
        '#options' => $options,
        '#size' => min(9, count($options)),
        '#default_value' => $default_value,
      );
      $user_input = $form_state
        ->getUserInput();
      if ($exposed && isset($identifier) && !isset($user_input[$identifier])) {
        $user_input[$identifier] = $default_value;
        $form_state
          ->setUserInput($user_input);
      }
    }
    if (!$form_state
      ->get('exposed')) {
      
      $this->helper
        ->buildOptionsForm($form, $form_state);
    }
  }
  protected function valueValidate($form, FormStateInterface $form_state) {
    
    if ($this->options['type'] != 'textfield') {
      return;
    }
    $tids = array();
    foreach ($form_state
      ->getValue(array(
      'options',
      'value',
    )) as $value) {
      $tids[] = $value['target_id'];
    }
    $form_state
      ->setValue(array(
      'options',
      'value',
    ), $tids);
  }
  public function acceptExposedInput($input) {
    if (empty($this->options['exposed'])) {
      return TRUE;
    }
    
    if (!empty($this->options['expose']['use_operator']) && !empty($this->options['expose']['operator_id']) && isset($input[$this->options['expose']['operator_id']])) {
      $this->operator = $input[$this->options['expose']['operator_id']];
    }
    
    if (!empty($this->view->is_attachment) && $this->view->display_handler
      ->usesExposed()) {
      $this->validated_exposed_input = (array) $this->view->exposed_raw_input[$this->options['expose']['identifier']];
    }
    
    if ($this->operator == 'empty' || $this->operator == 'not empty') {
      return TRUE;
    }
    
    if (!$this->options['expose']['required'] && empty($this->validated_exposed_input)) {
      return FALSE;
    }
    $rc = parent::acceptExposedInput($input);
    if ($rc) {
      
      if (isset($this->validated_exposed_input)) {
        $this->value = $this->validated_exposed_input;
      }
    }
    return $rc;
  }
  public function validateExposed(&$form, FormStateInterface $form_state) {
    if (empty($this->options['exposed'])) {
      return;
    }
    $identifier = $this->options['expose']['identifier'];
    
    if ($this->options['type'] != 'textfield') {
      if ($form_state
        ->getValue($identifier) != 'All') {
        $this->validated_exposed_input = (array) $form_state
          ->getValue($identifier);
      }
      return;
    }
    if (empty($this->options['expose']['identifier'])) {
      return;
    }
    foreach ($form_state
      ->getValue($identifier) as $value) {
      $this->validated_exposed_input[] = $value['target_id'];
    }
  }
  protected function valueSubmit($form, FormStateInterface $form_state) {
    
  }
  public function buildExposeForm(&$form, FormStateInterface $form_state) {
    parent::buildExposeForm($form, $form_state);
    if ($this->options['type'] != 'select') {
      unset($form['expose']['reduce']);
    }
    $form['error_message'] = array(
      '#type' => 'checkbox',
      '#title' => $this
        ->t('Display error message'),
      '#default_value' => !empty($this->options['error_message']),
    );
  }
  public function adminSummary() {
    
    $this->valueOptions = array();
    if ($this->value) {
      $this->value = array_filter($this->value);
      $terms = Term::loadMultiple($this->value);
      foreach ($terms as $term) {
        $this->valueOptions[$term
          ->id()] = \Drupal::entityManager()
          ->getTranslationFromContext($term)
          ->label();
      }
    }
    return parent::adminSummary();
  }
  
  public function getCacheContexts() {
    $contexts = parent::getCacheContexts();
    
    $contexts[] = 'user';
    return $contexts;
  }
  
  public function calculateDependencies() {
    $dependencies = parent::calculateDependencies();
    $vocabulary = $this->vocabularyStorage
      ->load($this->options['vid']);
    $dependencies[$vocabulary
      ->getConfigDependencyKey()][] = $vocabulary
      ->getConfigDependencyName();
    foreach ($this->options['value'] as $tid) {
      $term = $this->termStorage
        ->load($tid);
      $dependencies[$term
        ->getConfigDependencyKey()][] = $term
        ->getConfigDependencyName();
    }
    return $dependencies;
  }
}