RevisionLink.php

<?php

namespace Drupal\node\Plugin\views\field;

use Drupal\Core\Url;
use Drupal\views\Plugin\views\field\LinkBase;
use Drupal\views\ResultRow;

/**
 * Field handler to present a link to a node revision.
 *
 * @ingroup views_field_handlers
 *
 * @ViewsField("node_revision_link")
 */
class RevisionLink extends LinkBase {
    
    /**
     * {@inheritdoc}
     */
    protected function getUrlInfo(ResultRow $row) {
        
        /** @var \Drupal\node\NodeInterface $node */
        $node = $this->getEntity($row);
        // Current revision uses the node view path.
        return !$node->isDefaultRevision() ? Url::fromRoute('entity.node.revision', [
            'node' => $node->id(),
            'node_revision' => $node->getRevisionId(),
        ]) : $node->toUrl();
    }
    
    /**
     * {@inheritdoc}
     */
    protected function renderLink(ResultRow $row) {
        
        /** @var \Drupal\node\NodeInterface $node */
        $node = $this->getEntity($row);
        if (!$node->getRevisionid()) {
            return '';
        }
        $text = parent::renderLink($row);
        $this->options['alter']['query'] = $this->getDestinationArray();
        return $text;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function getDefaultLabel() {
        return $this->t('View');
    }

}