yii\console\controllers\MessageController::saveMessagesCategoryToPHP PHP Method

    protected function saveMessagesCategoryToPHP($messages, $fileName, $overwrite, $removeUnused, $sort, $category, $markUnused)
    {
        if (is_file($fileName)) {
            $rawExistingMessages = (require $fileName);
            $existingMessages = $rawExistingMessages;
            sort($messages);
            ksort($existingMessages);
            if (array_keys($existingMessages) === $messages && (!$sort || array_keys($rawExistingMessages) === $messages)) {
                $this->stdout("Nothing new in \"{$category}\" category... Nothing to save.\n\n", Console::FG_GREEN);
                return self::EXIT_CODE_NORMAL;
            }
            unset($rawExistingMessages);
            $merged = [];
            $untranslated = [];
            foreach ($messages as $message) {
                if (array_key_exists($message, $existingMessages) && $existingMessages[$message] !== '') {
                    $merged[$message] = $existingMessages[$message];
                } else {
                    $untranslated[] = $message;
                }
            }
            ksort($merged);
            sort($untranslated);
            $todo = [];
            foreach ($untranslated as $message) {
                $todo[$message] = '';
            }
            ksort($existingMessages);
            foreach ($existingMessages as $message => $translation) {
                if (!$removeUnused && !isset($merged[$message]) && !isset($todo[$message])) {
                    if (!empty($translation) && (!$markUnused || strncmp($translation, '@@', 2) === 0 && substr_compare($translation, '@@', -2, 2) === 0)) {
                        $todo[$message] = $translation;
                    } else {
                        $todo[$message] = '@@' . $translation . '@@';
                    }
                }
            }
            $merged = array_merge($todo, $merged);
            if ($sort) {
                ksort($merged);
            }
            if (false === $overwrite) {
                $fileName .= '.merged';
            }
            $this->stdout("Translation merged.\n");
        } else {
            $merged = [];
            foreach ($messages as $message) {
                $merged[$message] = '';
            }
            ksort($merged);
        }
        $array = VarDumper::export($merged);
        $content = <<<EOD
<?php
/**
 * Message translations.
 *
 * This file is automatically generated by 'yii {$this->id}/{$this->action->id}' command.
 * It contains the localizable messages extracted from source code.
 * You may modify this file by translating the extracted messages.
 *
 * Each array element represents the translation (value) of a message (key).
 * If the value is empty, the message is considered as not translated.
 * Messages that no longer need translation will have their translations
 * enclosed between a pair of '@@' marks.
 *
 * Message string can be used with plural forms format. Check i18n section
 * of the guide for details.
 *
 * NOTE: this file must be saved in UTF-8 encoding.
 */
return {$array};

EOD;
        if (file_put_contents($fileName, $content) !== false) {
            $this->stdout("Translation saved.\n\n", Console::FG_GREEN);
            return self::EXIT_CODE_NORMAL;
        } else {
            $this->stdout("Translation was NOT saved.\n\n", Console::FG_RED);
            return self::EXIT_CODE_ERROR;
        }
    }