protected function getMainPropertyName(FieldItemInterface $data)
{
return $data->getFieldDefinition()->getFieldStorageDefinition()->getMainPropertyName();
}
/**
* {@inheritdoc}
*/
public function viewFieldItem(FieldItemInterface $item, $display = array())
{
$entity = $item->getEntity();
$field_name = $item->getFieldDefinition()->getName();
// Clone the entity since we are going to modify field values.
$clone = clone $entity;
// Push the item as the single value for the field, and defer to viewField()
// to build the render array for the whole list.
$clone->{$field_name}->setValue(array($item->getValue()));
$elements = $this->viewField($clone->{$field_name}, $display);
// Extract the part of the render array we need.
$output = isset($elements[0]) ? $elements[0] : array();
if (isset($elements['#access'])) {
$output['#access'] = $elements['#access'];
}
return $output;
}
/**
* Get a translated version of the field item instance.
*
* To indicate that a field item applies to one translation of an entity and
* not another, the property path must originate with a translation of the
* entity. This is the reason for using target_instances, from which the
* property path can be traversed up to the root.
*
* @param \Drupal\Core\Field\FieldItemInterface $field_item
* The untranslated field item instance.
* @param $langcode
* The langcode.
*
* @return \Drupal\Core\Field\FieldItemInterface
* The translated field item instance.
*/
protected function createTranslatedInstance(FieldItemInterface $item, $langcode)
{
// Remove the untranslated item that was created for the default language
// by FieldNormalizer::denormalize().
$items = $item->getParent();
$delta = $item->getName();
unset($items[$delta]);
// Instead, create a new item for the entity in the requested language.
$entity = $item->getEntity();
$entity_translation = $entity->hasTranslation($langcode) ? $entity->getTranslation($langcode) : $entity->addTranslation($langcode);
$field_name = $item->getFieldDefinition()->getName();
return $entity_translation->get($field_name)->appendItem();
}
/**
* Get a translated version of the field item instance.
*
* To indicate that a field item applies to one translation of an entity and
* not another, the property path must originate with a translation of the
* entity. This is the reason for using target_instances, from which the
* property path can be traversed up to the root.
*
* @param \Drupal\Core\Field\FieldItemInterface $field_item
* The untranslated field item instance.
* @param $langcode
* The langcode.
*
* @return \Drupal\Core\Field\FieldItemInterface
* The translated field item instance.
*/
protected function createTranslatedInstance(FieldItemInterface $field_item, $langcode)
{
$field_items = $field_item->getParent();
// Remove the untranslated instance from the field's list of items.
$field_items->offsetUnset($field_item->getName());
// Get the entity in the requested language and the field's item list from
// that.
$entity_translation = $field_item->getEntity()->getTranslation($langcode);
$field_items_translation = $entity_translation->get($field_item->getFieldDefinition()->getName());
// Create a new instance and return it.
$count = $field_items_translation->isEmpty() ? 0 : $field_items_translation->count();
return $field_items_translation->get($count);
}
