EntityLink.php

<?php

namespace Drupal\views\Plugin\views\field;

use Drupal\Core\Form\FormStateInterface;
use Drupal\views\Attribute\ViewsField;
use Drupal\views\ResultRow;

/**
 * Field handler to present a link to an entity.
 *
 * @ingroup views_field_handlers
 */
class EntityLink extends LinkBase {
    
    /**
     * {@inheritdoc}
     */
    public function render(ResultRow $row) {
        return $this->getEntity($row) ? parent::render($row) : [];
    }
    
    /**
     * {@inheritdoc}
     */
    protected function renderLink(ResultRow $row) {
        if ($this->options['output_url_as_text']) {
            $url_info = $this->getUrlInfo($row);
            return $url_info ? $url_info->toString() : '';
        }
        return parent::renderLink($row);
    }
    
    /**
     * {@inheritdoc}
     */
    protected function getUrlInfo(ResultRow $row) {
        $template = $this->getEntityLinkTemplate();
        $entity = $this->getEntity($row);
        if ($entity === NULL) {
            return NULL;
        }
        if ($this->languageManager
            ->isMultilingual()) {
            $entity = $this->getEntityTranslationByRelationship($entity, $row);
        }
        return $entity->toUrl($template)
            ->setAbsolute($this->options['absolute']);
    }
    
    /**
     * Returns the entity link template name identifying the link route.
     *
     * @return string
     *   The link template name.
     */
    protected function getEntityLinkTemplate() {
        return 'canonical';
    }
    
    /**
     * {@inheritdoc}
     */
    protected function getDefaultLabel() {
        return $this->t('view');
    }
    
    /**
     * {@inheritdoc}
     */
    protected function defineOptions() {
        $options = parent::defineOptions();
        $options['output_url_as_text'] = [
            'default' => FALSE,
        ];
        $options['absolute'] = [
            'default' => FALSE,
        ];
        return $options;
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildOptionsForm(&$form, FormStateInterface $form_state) {
        $form['output_url_as_text'] = [
            '#type' => 'checkbox',
            '#title' => $this->t('Output the URL as text'),
            '#default_value' => $this->options['output_url_as_text'],
        ];
        $form['absolute'] = [
            '#type' => 'checkbox',
            '#title' => $this->t('Use absolute link (begins with "http://")'),
            '#default_value' => $this->options['absolute'],
            '#description' => $this->t('Enable this option to output an absolute link. Required if you want to use the path as a link destination.'),
        ];
        parent::buildOptionsForm($form, $form_state);
        // Only show the 'text' field if we don't want to output the raw URL.
        $form['text']['#states']['visible'][':input[name="options[output_url_as_text]"]'] = [
            'checked' => FALSE,
        ];
    }

}