Convert multidimensional array to dot notation in Symfony2 - php

Question

Symfony converts nested YAML and PHP array translation files to a dot notation, like this: modules.module.title.
I'm writing some code that exports YAML translation files to a database, and I need to flatten the parsed files to a dot notation.
Does anyone know which function Symfony uses to flatten nested arrays to dot notation?
I cannot find it anywhere in the source code.

Answer 1

It's the flatten() method in Symfony\Component\Translation\Loader\ArrayLoader:
<?php
/**
* Flattens an nested array of translations.
*
* The scheme used is:
* 'key' => array('key2' => array('key3' => 'value'))
* Becomes:
* 'key.key2.key3' => 'value'
*
* This function takes an array by reference and will modify it
*
* #param array &$messages The array that will be flattened
* #param array $subnode Current subnode being parsed, used internally for recursive calls
* #param string $path Current path being parsed, used internally for recursive calls
*/
private function flatten(array &$messages, array $subnode = null, $path = null)
{
if (null === $subnode) {
$subnode = &$messages;
}
foreach ($subnode as $key => $value) {
if (is_array($value)) {
$nodePath = $path ? $path.'.'.$key : $key;
$this->flatten($messages, $value, $nodePath);
if (null === $path) {
unset($messages[$key]);
}
} elseif (null !== $path) {
$messages[$path.'.'.$key] = $value;
}
}
}

Answer 2

I don't know how what is written in previous Symfony versions, but in Symfony 4.2 onwards translations are returned already flattened.
Example controller which returns the messages catalogue translations. In my case I used this response to feed the i18next js library.
<?php
declare(strict_types=1);
namespace Conferences\Controller;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
use Symfony\Component\Translation\TranslatorBagInterface;
use Symfony\Contracts\Translation\TranslatorInterface;
final class TranslationsController
{
public function __invoke(TranslatorInterface $translator): JsonResponse
{
if (!$translator instanceof TranslatorBagInterface) {
throw new ServiceUnavailableHttpException();
}
return new JsonResponse($translator->getCatalogue()->all()['messages']);
}
}
Route definition:
translations:
path: /{_locale}/translations
controller: App\Controller\TranslationsController
requirements: {_locale: pl|en}