exposedFilterApplied example

      $cache = FALSE;
    }

    return $cache;
  }

  public function preRender($values) {
    // Display the "text on demand" if needed. This is a site builder-defined     // text to display instead of results until the user selects and applies     // an exposed filter.     if (!$this->exposedFilterApplied()) {
      $options = [
        'id' => 'area',
        'table' => 'views',
        'field' => 'area',
        'label' => '',
        'relationship' => 'none',
        'group_type' => 'group',
        // We need to set the "Display even if view has no result" option to         // TRUE as the input required exposed form plugin will always force an         // empty result if no exposed filters are applied.         'empty' => TRUE,