materio-d8/modules/custom/materio_samples/src/Plugin/Field/FieldFormatter/SamplesDefaultFormatter.php

<?php

namespace Drupal\materio_samples\Plugin\Field\FieldFormatter;

use Drupal\Core\Field\FormatterBase;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\taxonomy\Entity\Term;

/**
 * Plugin implementation of the 'materio_samples_default_formatter' formatter.
 *
 * @FieldFormatter(
 *   id = "materio_samples_default_formatter",
 *   module = "materio_samples",
 *   label = @Translation("Simple list key paired formatter"),
 *   field_types = {
 *     "materio_samples_field"
 *   }
 * )
 */
class SamplesDefaultFormatter extends FormatterBase {

  /**
   * {@inheritdoc}
   */
  public function viewElements(FieldItemListInterface $items, $langcode) {
    $language = \Drupal::languageManager()->getCurrentLanguage()->getId();

    $elements = [];
    foreach ($items as $delta => $item) {
      // return nothing if target_id is null
      if(!$item->target_id) return;

      $term = Term::load($item->target_id);

      // translate the term
      $term = \Drupal::service('entity.repository')->getTranslationFromContext($term, $language);

      $elements[$delta] = [
        // We create a render array to produce the desired markup,
        // "<p style="color: #hexcolor">The color code ... #hexcolor</p>".
        // See theme_html_tag().
        '#type' => 'html_tag',
        '#tag' => 'span',
        '#value' => $this->t('@target : @location', [
            '@target' => $term->getName(),
            '@location' => $item->location
          ]
        ),
      ];
    }


    return $elements;
  }

}