Yaml Translation FileDump with append functionality

services.yaml

    translation.dumper.yaml:
        class:  App\Dumper\YamlxFileDumper
        tags:
            - { name: translation.dumper, alias: yaml }

YamlxFileDumper.php

<?php


namespace App\Dumper;


use Symfony\Component\Translation\Dumper\FileDumper;
use Symfony\Component\Translation\Dumper\YamlFileDumper;
use Symfony\Component\Translation\Exception\InvalidArgumentException;
use Symfony\Component\Translation\Exception\LogicException;
use Symfony\Component\Translation\Exception\RuntimeException;
use Symfony\Component\Translation\MessageCatalogue;
use Symfony\Component\Translation\Util\ArrayConverter;
use Symfony\Component\Yaml\Yaml;

class YamlxFileDumper extends YamlFileDumper
{

    /**
     * {@inheritdoc}
     */
    protected function getExtension()
    {
        return 'yaml';
    }


    /**
     * {@inheritdoc}
     */
    public function dump(MessageCatalogue $messages, $options = [])
    {
        if (!\array_key_exists('path', $options)) {
            throw new InvalidArgumentException('The file dumper needs a path option.');
        }

        // save a file for each domain
        foreach ($messages->getDomains() as $domain) {
            $fullpath = $options['path'].'/'.$this->getRelativePath($domain, $messages->getLocale());
            if (!file_exists($fullpath)) {
                $directory = \dirname($fullpath);
                if (!file_exists($directory) && !@mkdir($directory, 0777, true)) {
                    throw new RuntimeException(sprintf('Unable to create directory "%s".', $directory));
                }
            }

            $intlDomain = $domain.MessageCatalogue::INTL_DOMAIN_SUFFIX;
            $intlMessages = $messages->all($intlDomain);

            if ($intlMessages) {
                $intlPath = $options['path'].'/'.$this->getRelativePath($intlDomain, $messages->getLocale());
                file_put_contents($intlPath, $this->formatCatalogue($messages, $intlDomain, $options));

                $messages->replace([], $intlDomain);

                try {
                    if ($messages->all($domain)) {
                        file_put_contents($fullpath, $this->formatCatalogue($messages, $domain, $options));
                    }
                    continue;
                } finally {
                    $messages->replace($intlMessages, $intlDomain);
                }
            }


            if (file_exists($fullpath)) {
                $hasNewMessages = false;
                $existingYaml = Yaml::parseFile($fullpath);

                if ($existingYaml) {
                    $flattenYaml = $this->array_flat($existingYaml);

                    $newMessages = new MessageCatalogue($messages->getLocale());

                    $all = $messages->all($domain);
                    foreach ($all as $k => $me) {
                        if (!isset($flattenYaml[$k])) {
                            $hasNewMessages = true;
                            $newMessages->add([$k => $me], $domain);
                        }
                    }

                    if ($hasNewMessages) {
                        $output = file_get_contents($fullpath) . PHP_EOL . $this->formatCatalogue($newMessages, $domain, $options);
                        file_put_contents($fullpath, $output);
                    }
                }
            } else {
                $output = $this->formatCatalogue($messages, $domain, $options);
                file_put_contents($fullpath, $output);
            }

        }
    }


    /**
     * Gets the relative file path using the template.
     */
    private function getRelativePath(string $domain, string $locale): string
    {
        return strtr($this->relativePathTemplate, [
            '%domain%' => $domain,
            '%locale%' => $locale,
            '%extension%' => $this->getExtension(),
        ]);
    }

    function array_flat(array $array, string $prefix = ''): array
    {
        $result = array();

        foreach ($array as $key => $value) {
            $new_key = $prefix . (empty($prefix) ? '' : '.') . $key;

            if (is_array($value)) {
                $result = array_merge($result, $this->array_flat($value, $new_key));
            } else {
                $result[$new_key] = $value;
            }
        }

        return $result;
    }
}