Rss.php

<?php

namespace Drupal\aggregator\Plugin\views\row;

use Drupal\views\Plugin\views\row\RssPluginBase;

/**
 * Defines a row plugin which loads an aggregator item and renders as RSS.
 *
 * @ViewsRow(
 *   id = "aggregator_rss",
 *   theme = "views_view_row_rss",
 *   title = @Translation("Aggregator item"),
 *   help = @Translation("Display the aggregator item using the data from the original source."),
 *   base = {"aggregator_item"},
 *   display_types = {"feed"}
 * )
 */
class Rss extends RssPluginBase {
    
    /**
     * The table the aggregator item is using for storage.
     *
     * @var string
     */
    public $base_table = 'aggregator_item';
    
    /**
     * The actual field which is used to identify a aggregator item.
     *
     * @var string
     */
    public $base_field = 'iid';
    
    /**
     * {@inheritdoc}
     */
    protected $entityTypeId = 'aggregator_item';
    
    /**
     * {@inheritdoc}
     */
    public function render($row) {
        $entity = $row->_entity;
        $item = new \stdClass();
        foreach ($entity as $name => $field) {
            $item->{$name} = $field->value;
        }
        $item->elements = [
            [
                'key' => 'pubDate',
                // views_view_row_rss takes care about the escaping.
'value' => gmdate('r', $entity->timestamp->value),
            ],
            [
                'key' => 'dc:creator',
                // views_view_row_rss takes care about the escaping.
'value' => $entity->author->value,
            ],
            [
                'key' => 'guid',
                // views_view_row_rss takes care about the escaping.
'value' => $entity->guid->value,
                'attributes' => [
                    'isPermaLink' => 'false',
                ],
            ],
        ];
        $build = [
            '#theme' => $this->themeFunctions(),
            '#view' => $this->view,
            '#options' => $this->options,
            '#row' => $item,
        ];
        return $build;
    }

}