yii\i18n\GettextMessageSource::loadFallbackMessages PHP Метод

    protected function loadFallbackMessages($category, $fallbackLanguage, $messages, $originalMessageFile)
    {
        $fallbackMessageFile = $this->getMessageFilePath($fallbackLanguage);
        $fallbackMessages = $this->loadMessagesFromFile($fallbackMessageFile, $category);
        if ($messages === null && $fallbackMessages === null && $fallbackLanguage !== $this->sourceLanguage && $fallbackLanguage !== substr($this->sourceLanguage, 0, 2)) {
            Yii::error("The message file for category '{$category}' does not exist: {$originalMessageFile} " . "Fallback file does not exist as well: {$fallbackMessageFile}", __METHOD__);
        } elseif (empty($messages)) {
            return $fallbackMessages;
        } elseif (!empty($fallbackMessages)) {
            foreach ($fallbackMessages as $key => $value) {
                if (!empty($value) && empty($messages[$key])) {
                    $messages[$key] = $fallbackMessages[$key];
                }
            }
        }
        return (array) $messages;
    }