ContentEntityBase::getTranslatedField

protected ContentEntityBase::getTranslatedField($name, $langcode)

protected function getTranslatedField($name, $langcode) {
  if ($this->translations[$this->activeLangcode]['status'] == static::TRANSLATION_REMOVED) {
    throw new \InvalidArgumentException("The entity object refers to a removed translation ({$this->activeLangcode}) and cannot be manipulated.");
  }
  // Populate $this->fields to speed-up further look-ups and to keep track of
  // fields objects, possibly holding changes to field values.
  if (!isset($this->fields[$name][$langcode])) {
    $definition = $this->getFieldDefinition($name);
    if (!$definition) {
      throw new \InvalidArgumentException("Field $name is unknown.");
    }
    // Non-translatable fields are always stored with
    // LanguageInterface::LANGCODE_DEFAULT as key.

    $default = $langcode == LanguageInterface::LANGCODE_DEFAULT;
    if (!$default && !$definition->isTranslatable()) {
      if (!isset($this->fields[$name][LanguageInterface::LANGCODE_DEFAULT])) {
        $this->fields[$name][LanguageInterface::LANGCODE_DEFAULT] = $this->getTranslatedField($name, LanguageInterface::LANGCODE_DEFAULT);
      }
      $this->fields[$name][$langcode] = &$this->fields[$name][LanguageInterface::LANGCODE_DEFAULT];
    }
    else {
      $value = NULL;
      if (isset($this->values[$name][$langcode])) {
        $value = $this->values[$name][$langcode];
      }
      $field = \Drupal::service('plugin.manager.field.field_type')->createFieldItemList($this->getTranslation($langcode), $name, $value);
      if ($default) {
        // $this->defaultLangcode might not be set if we are initializing the
        // default language code cache, in which case there is no valid
        // langcode to assign.
        $field_langcode = isset($this->defaultLangcode) ? $this->defaultLangcode : LanguageInterface::LANGCODE_NOT_SPECIFIED;
      }
      else {
        $field_langcode = $langcode;
      }
      $field->setLangcode($field_langcode);
      $this->fields[$name][$langcode] = $field;
    }
  }
  return $this->fields[$name][$langcode];
}