Result.php

<?php

namespace Drupal\views\Plugin\views\area;

use Drupal\Component\Utility\Html;
use Drupal\Component\Utility\Xss;
use Drupal\Core\Form\FormStateInterface;
use Drupal\views\Plugin\views\style\DefaultSummary;

/**
 * Views area handler to display some configurable result summary.
 *
 * @ingroup views_area_handlers
 *
 * @ViewsArea("result")
 */
class Result extends AreaPluginBase {
    
    /**
     * {@inheritdoc}
     */
    protected function defineOptions() {
        $options = parent::defineOptions();
        $options['content'] = [
            'default' => $this->t('Displaying @start - @end of @total'),
        ];
        return $options;
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildOptionsForm(&$form, FormStateInterface $form_state) {
        parent::buildOptionsForm($form, $form_state);
        $item_list = [
            '#theme' => 'item_list',
            '#items' => [
                '@start -- the initial record number in the set',
                '@end -- the last record number in the set',
                '@total -- the total records in the set',
                '@label -- the human-readable name of the view',
                '@per_page -- the number of items per page',
                '@current_page -- the current page number',
                '@current_record_count -- the current page record count',
                '@page_count -- the total page count',
            ],
        ];
        $list = \Drupal::service('renderer')->render($item_list);
        $form['content'] = [
            '#title' => $this->t('Display'),
            '#type' => 'textarea',
            '#rows' => 3,
            '#default_value' => $this->options['content'],
            '#description' => $this->t('You may use HTML code in this field. The following tokens are supported:') . $list,
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function query() {
        if (strpos($this->options['content'], '@total') !== FALSE) {
            $this->view->get_total_rows = TRUE;
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function render($empty = FALSE) {
        // Must have options and does not work on summaries.
        if (!isset($this->options['content']) || $this->view->style_plugin instanceof DefaultSummary) {
            return [];
        }
        $output = '';
        $format = $this->options['content'];
        // Calculate the page totals.
        $current_page = (int) $this->view
            ->getCurrentPage() + 1;
        $per_page = (int) $this->view
            ->getItemsPerPage();
        // @TODO: Maybe use a possible is views empty functionality.
        // Not every view has total_rows set, use view->result instead.
        $total = isset($this->view->total_rows) ? $this->view->total_rows : count($this->view->result);
        $label = Html::escape($this->view->storage
            ->label());
        // If there is no result the "start" and "current_record_count" should be
        // equal to 0. To have the same calculation logic, we use a "start offset"
        // to handle all the cases.
        $start_offset = empty($total) ? 0 : 1;
        if ($per_page === 0) {
            $page_count = 1;
            $start = $start_offset;
            $end = $total;
        }
        else {
            $page_count = (int) ceil($total / $per_page);
            $total_count = $current_page * $per_page;
            if ($total_count > $total) {
                $total_count = $total;
            }
            $start = ($current_page - 1) * $per_page + $start_offset;
            $end = $total_count;
        }
        $current_record_count = $end - $start + $start_offset;
        // Get the search information.
        $replacements = [];
        $replacements['@start'] = $start;
        $replacements['@end'] = $end;
        $replacements['@total'] = $total;
        $replacements['@label'] = $label;
        $replacements['@per_page'] = $per_page;
        $replacements['@current_page'] = $current_page;
        $replacements['@current_record_count'] = $current_record_count;
        $replacements['@page_count'] = $page_count;
        // Send the output.
        if (!empty($total) || !empty($this->options['empty'])) {
            $output .= Xss::filterAdmin(str_replace(array_keys($replacements), array_values($replacements), $format));
            // Return as render array.
            return [
                '#markup' => $output,
            ];
        }
        return [];
    }

}