class TaxonomyIndexTid

1. 8.x drupal/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/views/field/TaxonomyIndexTid.php \Drupal\taxonomy\Plugin\views\field\TaxonomyIndexTid
2. 8.x drupal/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/views/filter/TaxonomyIndexTid.php \Drupal\taxonomy\Plugin\views\filter\TaxonomyIndexTid

class TaxonomyIndexTid extends ManyToOne {

  // Stores the exposed input for this filter.
  var $validated_exposed_input = NULL;

  /**
   * Overrides \Drupal\views\Plugin\views\filter\ManyToOne::init().
   */
  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() {

    /* don't overwrite the value options */
  }
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['type'] = array(
      'default' => 'textfield',
    );
    $options['limit'] = array(
      'default' => TRUE,
      'bool' => TRUE,
    );
    $options['vid'] = array(
      'default' => '',
    );
    $options['hierarchy'] = array(
      'default' => 0,
    );
    $options['error_message'] = array(
      'default' => TRUE,
      'bool' => TRUE,
    );
    return $options;
  }
  public function buildExtraOptionsForm(&$form, &$form_state) {
    $vocabularies = entity_load_multiple('taxonomy_vocabulary');
    $options = array();
    foreach ($vocabularies as $voc) {
      $options[$voc
        ->id()] = $voc
        ->label();
    }
    if ($this->options['limit']) {

      // We only do this when the form is displayed.
      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' => t('Vocabulary'),
          '#options' => $options,
          '#description' => t('Select which vocabulary to show terms for in the regular options.'),
          '#default_value' => $this->options['vid'],
        );
      }
    }
    $form['type'] = array(
      '#type' => 'radios',
      '#title' => t('Selection type'),
      '#options' => array(
        'select' => t('Dropdown'),
        'textfield' => t('Autocomplete'),
      ),
      '#default_value' => $this->options['type'],
    );
    $form['hierarchy'] = array(
      '#type' => 'checkbox',
      '#title' => t('Show hierarchy in dropdown'),
      '#default_value' => !empty($this->options['hierarchy']),
      '#states' => array(
        'visible' => array(
          ':input[name="options[type]"]' => array(
            'value' => 'select',
          ),
        ),
      ),
    );
  }
  protected function valueForm(&$form, &$form_state) {
    $vocabulary = entity_load('taxonomy_vocabulary', $this->options['vid']);
    if (empty($vocabulary) && $this->options['limit']) {
      $form['markup'] = array(
        '#markup' => '<div class="form-item">' . t('An invalid vocabulary is selected. Please change it in the options.') . '</div>',
      );
      return;
    }
    if ($this->options['type'] == 'textfield') {
      $default = '';
      if ($this->value) {
        $result = db_select('taxonomy_term_data', 'td')
          ->fields('td')
          ->condition('td.tid', $this->value)
          ->execute();
        foreach ($result as $term) {
          if ($default) {
            $default .= ', ';
          }
          $default .= $term->name;
        }
      }
      $form['value'] = array(
        '#title' => $this->options['limit'] ? t('Select terms from vocabulary @voc', array(
          '@voc' => $vocabulary
            ->label(),
        )) : t('Select terms'),
        '#type' => 'textfield',
        '#default_value' => $default,
      );
      if ($this->options['limit']) {
        $form['value']['#autocomplete_path'] = 'admin/views/ajax/autocomplete/taxonomy/' . $vocabulary
          ->id();
      }
    }
    else {
      if (!empty($this->options['hierarchy']) && $this->options['limit']) {
        $tree = taxonomy_get_tree($vocabulary
          ->id());
        $options = array();
        if ($tree) {
          foreach ($tree as $term) {
            $choice = new stdClass();
            $choice->option = array(
              $term->tid => str_repeat('-', $term->depth) . $term->name,
            );
            $options[] = $choice;
          }
        }
      }
      else {
        $options = array();
        $query = db_select('taxonomy_term_data', 'td');
        $query
          ->fields('td');

        // @todo Sorting on vocabulary properties http://drupal.org/node/1821274
        $query
          ->orderby('td.weight');
        $query
          ->orderby('td.name');
        $query
          ->addTag('term_access');
        if ($this->options['limit']) {
          $query
            ->condition('td.vid', $vocabulary
            ->id());
        }
        $result = $query
          ->execute();
        foreach ($result as $term) {
          $options[$term->tid] = $term->name;
        }
      }
      $default_value = (array) $this->value;
      if (!empty($form_state['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'] ? t('Select terms from vocabulary @voc', array(
          '@voc' => $vocabulary
            ->label(),
        )) : t('Select terms'),
        '#multiple' => TRUE,
        '#options' => $options,
        '#size' => min(9, count($options)),
        '#default_value' => $default_value,
      );
      if (!empty($form_state['exposed']) && isset($identifier) && !isset($form_state['input'][$identifier])) {
        $form_state['input'][$identifier] = $default_value;
      }
    }
    if (empty($form_state['exposed'])) {

      // Retain the helper option
      $this->helper
        ->buildOptionsForm($form, $form_state);
    }
  }
  protected function valueValidate($form, &$form_state) {

    // We only validate if they've chosen the text field style.
    if ($this->options['type'] != 'textfield') {
      return;
    }
    $values = drupal_explode_tags($form_state['values']['options']['value']);
    $tids = $this
      ->validate_term_strings($form['value'], $values);
    if ($tids) {
      $form_state['values']['options']['value'] = $tids;
    }
  }
  public function acceptExposedInput($input) {
    if (empty($this->options['exposed'])) {
      return TRUE;
    }

    // If view is an attachment and is inheriting exposed filters, then assume
    // exposed input has already been validated
    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 it's non-required and there's no value don't bother filtering.
    if (!$this->options['expose']['required'] && empty($this->validated_exposed_input)) {
      return FALSE;
    }
    $rc = parent::acceptExposedInput($input);
    if ($rc) {

      // If we have previously validated input, override.
      if (isset($this->validated_exposed_input)) {
        $this->value = $this->validated_exposed_input;
      }
    }
    return $rc;
  }
  public function validateExposed(&$form, &$form_state) {
    if (empty($this->options['exposed'])) {
      return;
    }
    $identifier = $this->options['expose']['identifier'];

    // We only validate if they've chosen the text field style.
    if ($this->options['type'] != 'textfield') {
      if ($form_state['values'][$identifier] != 'All') {
        $this->validated_exposed_input = (array) $form_state['values'][$identifier];
      }
      return;
    }
    if (empty($this->options['expose']['identifier'])) {
      return;
    }
    $values = drupal_explode_tags($form_state['values'][$identifier]);
    $tids = $this
      ->validate_term_strings($form[$identifier], $values);
    if ($tids) {
      $this->validated_exposed_input = $tids;
    }
  }

  /**
   * Validate the user string. Since this can come from either the form
   * or the exposed filter, this is abstracted out a bit so it can
   * handle the multiple input sources.
   *
   * @param $form
   *   The form which is used, either the views ui or the exposed filters.
   * @param $values
   *   The taxonomy names which will be converted to tids.
   *
   * @return array
   *   The taxonomy ids fo all validated terms.
   */
  function validate_term_strings(&$form, $values) {
    if (empty($values)) {
      return array();
    }
    $tids = array();
    $names = array();
    $missing = array();
    foreach ($values as $value) {
      $missing[strtolower($value)] = TRUE;
      $names[] = $value;
    }
    if (!$names) {
      return FALSE;
    }
    $query = db_select('taxonomy_term_data', 'td');
    $query
      ->fields('td');
    $query
      ->condition('td.name', $names);
    $query
      ->condition('td.vid', $this->options['vid']);
    $query
      ->addTag('term_access');
    $result = $query
      ->execute();
    foreach ($result as $term) {
      unset($missing[strtolower($term->name)]);
      $tids[] = $term->tid;
    }
    if ($missing && !empty($this->options['error_message'])) {
      form_error($form, format_plural(count($missing), 'Unable to find term: @terms', 'Unable to find terms: @terms', array(
        '@terms' => implode(', ', array_keys($missing)),
      )));
    }
    elseif ($missing && empty($this->options['error_message'])) {
      $tids = array(
        0,
      );
    }
    return $tids;
  }
  protected function valueSubmit($form, &$form_state) {

    // prevent array_filter from messing up our arrays in parent submit.
  }
  public function buildExposeForm(&$form, &$form_state) {
    parent::buildExposeForm($form, $form_state);
    if ($this->options['type'] != 'select') {
      unset($form['expose']['reduce']);
    }
    $form['error_message'] = array(
      '#type' => 'checkbox',
      '#title' => t('Display error message'),
      '#default_value' => !empty($this->options['error_message']),
    );
  }
  public function adminSummary() {

    // set up $this->value_options for the parent summary
    $this->value_options = array();
    if ($this->value) {
      $this->value = array_filter($this->value);
      $result = db_select('taxonomy_term_data', 'td')
        ->fields('td')
        ->condition('td.tid', $this->value)
        ->execute();
      foreach ($result as $term) {
        $this->value_options[$term->tid] = $term->name;
      }
    }
    return parent::adminSummary();
  }

}