class String

1. 9.x drupal/core/lib/Drupal/Core/TypedData/Type/String.php \Drupal\Core\TypedData\Type\String
2. 9.x drupal/core/modules/views/lib/Drupal/views/Plugin/views/argument/String.php \Drupal\views\Plugin\views\argument\String
3. 9.x drupal/core/modules/views/lib/Drupal/views/Plugin/views/filter/String.php \Drupal\views\Plugin\views\filter\String

ListString.php in drupal/core/modules/field/lib/Drupal/field/Plugin/views/argument/ListString.php

Definition of Drupal\field\Plugin\views\argument\ListString.

Type.php in drupal/core/modules/node/lib/Drupal/node/Plugin/views/argument/Type.php

Definition of Drupal\node\Plugin\views\argument\Type.

VocabularyMachineName.php in drupal/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/views/argument/VocabularyMachineName.php

Definition of Drupal\taxonomy\Plugin\views\argument\VocabularyMachineName.

system_data_type_info in drupal/core/modules/system/system.module

Implements hook_data_type_info().

class String extends ArgumentPluginBase {
  public function init(ViewExecutable $view, &$options) {
    parent::init($view, $options);
    if (!empty($this->definition['many to one'])) {
      $this->helper = new ManyToOneHelper($this);

      // Ensure defaults for these, during summaries and stuff:
      $this->operator = 'or';
      $this->value = array();
    }
  }
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['glossary'] = array(
      'default' => FALSE,
      'bool' => TRUE,
    );
    $options['limit'] = array(
      'default' => 0,
    );
    $options['case'] = array(
      'default' => 'none',
    );
    $options['path_case'] = array(
      'default' => 'none',
    );
    $options['transform_dash'] = array(
      'default' => FALSE,
      'bool' => TRUE,
    );
    $options['break_phrase'] = array(
      'default' => FALSE,
      'bool' => TRUE,
    );
    if (!empty($this->definition['many to one'])) {
      $options['add_table'] = array(
        'default' => FALSE,
        'bool' => TRUE,
      );
      $options['require_value'] = array(
        'default' => FALSE,
        'bool' => TRUE,
      );
    }
    return $options;
  }
  public function buildOptionsForm(&$form, &$form_state) {
    parent::buildOptionsForm($form, $form_state);
    $form['glossary'] = array(
      '#type' => 'checkbox',
      '#title' => t('Glossary mode'),
      '#description' => t('Glossary mode applies a limit to the number of characters used in the filter value, which allows the summary view to act as a glossary.'),
      '#default_value' => $this->options['glossary'],
      '#fieldset' => 'more',
    );
    $form['limit'] = array(
      '#type' => 'textfield',
      '#title' => t('Character limit'),
      '#description' => t('How many characters of the filter value to filter against. If set to 1, all fields starting with the first letter in the filter value would be matched.'),
      '#default_value' => $this->options['limit'],
      '#states' => array(
        'visible' => array(
          ':input[name="options[glossary]"]' => array(
            'checked' => TRUE,
          ),
        ),
      ),
      '#fieldset' => 'more',
    );
    $form['case'] = array(
      '#type' => 'select',
      '#title' => t('Case'),
      '#description' => t('When printing the title and summary, how to transform the case of the filter value.'),
      '#options' => array(
        'none' => t('No transform'),
        'upper' => t('Upper case'),
        'lower' => t('Lower case'),
        'ucfirst' => t('Capitalize first letter'),
        'ucwords' => t('Capitalize each word'),
      ),
      '#default_value' => $this->options['case'],
      '#fieldset' => 'more',
    );
    $form['path_case'] = array(
      '#type' => 'select',
      '#title' => t('Case in path'),
      '#description' => t('When printing url paths, how to transform the case of the filter value. Do not use this unless with Postgres as it uses case sensitive comparisons.'),
      '#options' => array(
        'none' => t('No transform'),
        'upper' => t('Upper case'),
        'lower' => t('Lower case'),
        'ucfirst' => t('Capitalize first letter'),
        'ucwords' => t('Capitalize each word'),
      ),
      '#default_value' => $this->options['path_case'],
      '#fieldset' => 'more',
    );
    $form['transform_dash'] = array(
      '#type' => 'checkbox',
      '#title' => t('Transform spaces to dashes in URL'),
      '#default_value' => $this->options['transform_dash'],
      '#fieldset' => 'more',
    );
    if (!empty($this->definition['many to one'])) {
      $form['add_table'] = array(
        '#type' => 'checkbox',
        '#title' => t('Allow multiple filter values to work together'),
        '#description' => t('If selected, multiple instances of this filter can work together, as though multiple values were supplied to the same filter. This setting is not compatible with the "Reduce duplicates" setting.'),
        '#default_value' => !empty($this->options['add_table']),
        '#fieldset' => 'more',
      );
      $form['require_value'] = array(
        '#type' => 'checkbox',
        '#title' => t('Do not display items with no value in summary'),
        '#default_value' => !empty($this->options['require_value']),
        '#fieldset' => 'more',
      );
    }

    // allow + for or, , for and
    $form['break_phrase'] = array(
      '#type' => 'checkbox',
      '#title' => t('Allow multiple values'),
      '#description' => t('If selected, users can enter multiple values in the form of 1+2+3 (for OR) or 1,2,3 (for AND).'),
      '#default_value' => !empty($this->options['break_phrase']),
      '#fieldset' => 'more',
    );
  }

  /**
   * Build the summary query based on a string
   */
  function summary_query() {
    if (empty($this->definition['many to one'])) {
      $this
        ->ensureMyTable();
    }
    else {
      $this->tableAlias = $this->helper
        ->summary_join();
    }
    if (empty($this->options['glossary'])) {

      // Add the field.
      $this->base_alias = $this->query
        ->add_field($this->tableAlias, $this->realField);
      $this->query
        ->set_count_field($this->tableAlias, $this->realField);
    }
    else {

      // Add the field.
      $formula = $this
        ->get_formula();
      $this->base_alias = $this->query
        ->add_field(NULL, $formula, $this->field . '_truncated');
      $this->query
        ->set_count_field(NULL, $formula, $this->field, $this->field . '_truncated');
    }
    $this
      ->summary_name_field();
    return $this
      ->summary_basics(FALSE);
  }

  /**
   * Get the formula for this argument.
   *
   * $this->ensureMyTable() MUST have been called prior to this.
   */
  function get_formula() {
    return "SUBSTRING({$this->tableAlias}.{$this->realField}, 1, " . intval($this->options['limit']) . ")";
  }

  /**
   * Build the query based upon the formula
   */
  public function query($group_by = FALSE) {
    $argument = $this->argument;
    if (!empty($this->options['transform_dash'])) {
      $argument = strtr($argument, '-', ' ');
    }
    if (!empty($this->options['break_phrase'])) {
      $this
        ->breakPhraseString($argument, $this);
    }
    else {
      $this->value = array(
        $argument,
      );
      $this->operator = 'or';
    }
    if (!empty($this->definition['many to one'])) {
      if (!empty($this->options['glossary'])) {
        $this->helper->formula = TRUE;
      }
      $this->helper
        ->ensureMyTable();
      $this->helper
        ->add_filter();
      return;
    }
    $this
      ->ensureMyTable();
    $formula = FALSE;
    if (empty($this->options['glossary'])) {
      $field = "{$this->tableAlias}.{$this->realField}";
    }
    else {
      $formula = TRUE;
      $field = $this
        ->get_formula();
    }
    if (count($this->value) > 1) {
      $operator = 'IN';
      $argument = $this->value;
    }
    else {
      $operator = '=';
    }
    if ($formula) {
      $placeholder = $this
        ->placeholder();
      if ($operator == 'IN') {
        $field .= " IN({$placeholder})";
      }
      else {
        $field .= ' = ' . $placeholder;
      }
      $placeholders = array(
        $placeholder => $argument,
      );
      $this->query
        ->add_where_expression(0, $field, $placeholders);
    }
    else {
      $this->query
        ->add_where(0, $field, $argument, $operator);
    }
  }
  function summary_argument($data) {
    $value = $this
      ->caseTransform($data->{$this->base_alias}, $this->options['path_case']);
    if (!empty($this->options['transform_dash'])) {
      $value = strtr($value, ' ', '-');
    }
    return $value;
  }
  function get_sort_name() {
    return t('Alphabetical', array(), array(
      'context' => 'Sort order',
    ));
  }
  function title() {
    $this->argument = $this
      ->caseTransform($this->argument, $this->options['case']);
    if (!empty($this->options['transform_dash'])) {
      $this->argument = strtr($this->argument, '-', ' ');
    }
    if (!empty($this->options['break_phrase'])) {
      $this
        ->breakPhraseString($this->argument, $this);
    }
    else {
      $this->value = array(
        $this->argument,
      );
      $this->operator = 'or';
    }
    if (empty($this->value)) {
      return !empty($this->definition['empty field name']) ? $this->definition['empty field name'] : t('Uncategorized');
    }
    if ($this->value === array(
      -1,
    )) {
      return !empty($this->definition['invalid input']) ? $this->definition['invalid input'] : t('Invalid input');
    }
    return implode($this->operator == 'or' ? ' + ' : ', ', $this
      ->title_query());
  }

  /**
   * Override for specific title lookups.
   */
  function title_query() {
    return drupal_map_assoc($this->value, 'check_plain');
  }
  function summary_name($data) {
    return $this
      ->caseTransform(parent::summary_name($data), $this->options['case']);
  }

}