custom_formats.rst

.. index::
    single: Translation; Adding Custom Format Support

Adding Custom Format Support

Sometimes, you need to deal with custom formats for translation files. The Translation component is flexible enough to support this. Just create a loader (to load translations) and, optionally, a dumper (to dump translations).

Imagine that you have a custom format where translation messages are defined using one line for each translation and parentheses to wrap the key and the message. A translation file would look like this:

(welcome)(accueil)
(goodbye)(au revoir)
(hello)(bonjour)

Creating a Custom Loader

To define a custom loader that is able to read these kinds of files, you must create a new class that implements the :class:`Symfony\\Component\\Translation\\Loader\\LoaderInterface`. The :method:`Symfony\\Component\\Translation\\Loader\\LoaderInterface::load` method will get a filename and parse it into an array. Then, it will create the catalog that will be returned:

use Symfony\Component\Translation\MessageCatalogue;
use Symfony\Component\Translation\Loader\LoaderInterface;

class MyFormatLoader implements LoaderInterface
{
    public function load($resource, $locale, $domain = 'messages')
    {
        $messages = array();
        $lines = file($resource);

        foreach ($lines as $line) {
            if (preg_match('/\(([^\)]+)\)\(([^\)]+)\)/', $line, $matches)) {
                $messages[$matches[1]] = $matches[2];
            }
        }

        $messageCatalogue = new MessageCatalogue($locale);
        $messageCatalogue->add($messages, $domain);

        return $messageCatalogue;
    }

}

Once created, it can be used as any other loader:

use Symfony\Component\Translation\Translator;

$translator = new Translator('fr_FR');
$translator->addLoader('my_format', new MyFormatLoader());

$translator->addResource('my_format', __DIR__.'/translations/messages.txt', 'fr_FR');

var_dump($translator->trans('welcome'));

It will print "accueil".

Creating a Custom Dumper

It is also possible to create a custom dumper for your format, which is useful when using the extraction commands. To do so, a new class implementing the :class:`Symfony\\Component\\Translation\\Dumper\\DumperInterface` must be created. To write the dump contents into a file, extending the :class:`Symfony\\Component\\Translation\\Dumper\\FileDumper` class will save a few lines:

use Symfony\Component\Translation\MessageCatalogue;
use Symfony\Component\Translation\Dumper\FileDumper;

class MyFormatDumper extends FileDumper
{
    protected function format(MessageCatalogue $messages, $domain = 'messages')
    {
        $output = '';

        foreach ($messages->all($domain) as $source => $target) {
            $output .= sprintf("(%s)(%s)\n", $source, $target);
        }

        return $output;
    }

    protected function getExtension()
    {
        return 'txt';
    }
}

The :method:`Symfony\\Component\\Translation\\Dumper\\FileDumper::format` method creates the output string, that will be used by the :method:`Symfony\\Component\\Translation\\Dumper\\FileDumper::dump` method of the FileDumper class to create the file. The dumper can be used like any other built-in dumper. In the following example, the translation messages defined in the YAML file are dumped into a text file with the custom format:

use Symfony\Component\Translation\Loader\YamlFileLoader;

$loader = new YamlFileLoader();
$translations = $loader->load(__DIR__ . '/translations/messages.fr_FR.yml' , 'fr_FR');

$dumper = new MyFormatDumper();
$dumper->dump($translations, array('path' => __DIR__.'/dumps'));