SU-SWS/stanford_fields

<?php

namespace Drupal\stanford_fields\Plugin\Field\FieldFormatter;

use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Field\FormatterBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Link;
use Drupal\Core\Path\PathMatcherInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provide a string field to be used as a heading.
 *
 * @FieldFormatter(
 *   id = "entity_title_heading",
 *   label = @Translation("Heading"),
 *   field_types = {
 *     "string"
 *   }
 * )
 */
class EntityTitleHeading extends FormatterBase implements ContainerFactoryPluginInterface {

  /**
   * Path matcher service.
   *
   * @var \Drupal\Core\Path\PathMatcherInterface
   */
  protected $pathMatcher;

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static(
      $plugin_id,
      $plugin_definition,
      $configuration['field_definition'],
      $configuration['settings'],
      $configuration['label'],
      $configuration['view_mode'],
      $configuration['third_party_settings'],
      $container->get('path.matcher')
    );
  }

  /**
   * {@inheritdoc}
   */
  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, PathMatcherInterface $path_matcher) {
    parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $label, $view_mode, $third_party_settings);
    $this->pathMatcher = $path_matcher;
  }

  /**
   * {@inheritdoc}
   */
  public static function defaultSettings() {
    $settings = [
      'tag' => 'h2',
      'linked' => FALSE,
    ];
    return $settings + parent::defaultSettings();
  }

  /**
   * {@inheritdoc}
   */
  public function settingsForm(array $form, FormStateInterface $form_state) {
    $element = [];
    $heading_options = [];
    foreach (range(1, 5) as $level) {
      $heading_options['h' . $level] = 'H' . $level;
    }
    $element['tag'] = [
      '#title' => $this->t('Tag'),
      '#type' => 'select',
      '#description' => $this->t('Select the tag which will be wrapped around the title.'),
      '#options' => $heading_options,
      '#default_value' => $this->getSetting('tag'),
    ];
    return $element;
  }

  /**
   * {@inheritdoc}
   */
  public function settingsSummary() {
    $summary = parent::settingsSummary();
    $summary[] = $this->t('Header level: @level', ['@level' => $this->getSetting('tag')]);
    return $summary;
  }

  /**
   * {@inheritdoc}
   */
  public function viewElements(FieldItemListInterface $items, $langcode) {

    // Home page we don't want to display an H1 tag (page title).
    if ($this->pathMatcher->isFrontPage() && $this->getSetting('tag') == 'h1') {
      return [];
    }

    $output = [];
    foreach ($items->getValue() as $delta => $item) {
      $text = $item['value'];
      if ($this->getSetting('linked')) {
        $parent = $items->getParent()->getValue();
        $text = Link::fromTextAndUrl($text, $parent->toUrl())->toString();
      }
      $output[$delta] = [
        '#type' => 'html_tag',
        '#tag' => $this->getSetting('tag'),
        '#value' => $text,
      ];
    }
    return $output;
  }

}