single: Translations
The term "internationalization" (often abbreviated i18n) refers to the process of abstracting strings and other locale-specific pieces out of your application into a layer where they can be translated and converted based on the user's locale (i.e. language and country). For text, this means wrapping each with a function capable of translating the text (or "message") into the language of the user:
// text will *always* print out in English
dump('Hello World');
die();
// text can be translated into the end-user's language or
// default to English
dump($translator->trans('Hello World'));
die();
Note
The term locale refers roughly to the user's language and country. It can be any string that your application uses to manage translations and other format differences (e.g. currency format). The ISO 639-1 language code, an underscore (_
), then the ISO 3166-1 alpha-2 country code (e.g. fr_FR
for French/France) is recommended.
In this chapter, you'll learn how to use the Translation component in the Symfony Framework. You can read the Translation component documentation </components/translation/usage>
to learn even more. Overall, the process has several steps:
Enable and configure <translation-configuration>
Symfony's translation service;- Abstract strings (i.e. "messages") by wrapping them in calls to the
Translator
("translation-basic
"); Create translation resources/files <translation-resources>
for each supported locale that translate each message in the application;- Determine,
set and manage the user's locale </translation/locale>
for the request and optionallyon the user's entire session </session/locale_sticky_session>
.
Translations are handled by a translator
service that uses the user's locale to lookup and return translated messages. Before using it, enable the translator
in your configuration:
# app/config/config.yml
framework:
translator: { fallbacks: [en] }
<!-- app/config/config.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:framework="http://symfony.com/schema/dic/symfony"
xsi:schemaLocation="http://symfony.com/schema/dic/services
http://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/symfony
http://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
<framework:config>
<framework:translator>
<framework:fallback>en</framework:fallback>
</framework:translator>
</framework:config>
</container>
// app/config/config.php
$container->loadFromExtension('framework', array(
'translator' => array('fallbacks' => array('en')),
));
See translation-fallback
for details on the fallbacks
key and what Symfony does when it doesn't find a translation.
The locale used in translations is the one stored on the request. This is typically set via a _locale
attribute on your routes (see translation-locale-url
).
Translation of text is done through the translator
service (Symfony\\Component\\Translation\\Translator
). To translate a block of text (called a message), use the Symfony\\Component\\Translation\\Translator::trans
method. Suppose, for example, that you're translating a simple message from inside a controller:
// ...
use Symfony\Component\HttpFoundation\Response;
public function indexAction()
{
$translated = $this->get('translator')->trans('Symfony is great');
return new Response($translated);
}
When this code is executed, Symfony will attempt to translate the message "Symfony is great" based on the locale
of the user. For this to work, you need to tell Symfony how to translate the message via a "translation resource", which is usually a file that contains a collection of translations for a given locale. This "dictionary" of translations can be created in several different formats, XLIFF being the recommended format:
<!-- messages.fr.xlf -->
<?xml version="1.0"?>
<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
<file source-language="en" datatype="plaintext" original="file.ext">
<body>
<trans-unit id="symfony_is_great">
<source>Symfony is great</source>
<target>J'aime Symfony</target>
</trans-unit>
</body>
</file>
</xliff>
# messages.fr.yml
Symfony is great: J'aime Symfony
// messages.fr.php
return array(
'Symfony is great' => 'J\'aime Symfony',
);
For information on where these files should be located, see translation-resource-locations
.
Now, if the language of the user's locale is French (e.g. fr_FR
or fr_BE
), the message will be translated into J'aime Symfony
. You can also translate the message inside your templates <translation-tags>
.
To actually translate the message, Symfony uses a simple process:
- The
locale
of the current user, which is stored on the request is determined; - A catalog (e.g. big collection) of translated messages is loaded from translation resources defined for the
locale
(e.g.fr_FR
). Messages from thefallback locale <translation-fallback>
are also loaded and added to the catalog if they don't already exist. The end result is a large "dictionary" of translations. - If the message is located in the catalog, the translation is returned. If not, the translator returns the original message.
When using the trans()
method, Symfony looks for the exact string inside the appropriate message catalog and returns it (if it exists).
Sometimes, a message containing a variable needs to be translated:
use Symfony\Component\HttpFoundation\Response;
public function indexAction($name)
{
$translated = $this->get('translator')->trans('Hello '.$name);
return new Response($translated);
}
However, creating a translation for this string is impossible since the translator will try to look up the exact message, including the variable portions (e.g. "Hello Ryan" or "Hello Fabien").
For details on how to handle this situation, see component-translation-placeholders
in the components documentation. For how to do this in templates, see translation-tags
.
Another complication is when you have translations that may or may not be plural, based on some variable:
There is one apple.
There are 5 apples.
To handle this, use the Symfony\\Component\\Translation\\Translator::transChoice
method or the transchoice
tag/filter in your template <translation-tags>
.
For much more information, see component-translation-pluralization
in the Translation component documentation.
Most of the time, translation occurs in templates. Symfony provides native support for both Twig and PHP templates.
Symfony provides specialized Twig tags (trans
and transchoice
) to help with message translation of static blocks of text:
{% trans %}Hello %name%{% endtrans %}
{% transchoice count %}
{0} There are no apples|{1} There is one apple|]1,Inf[ There are %count% apples
{% endtranschoice %}
The transchoice
tag automatically gets the %count%
variable from the current context and passes it to the translator. This mechanism only works when you use a placeholder following the %var%
pattern.
Caution
The %var%
notation of placeholders is required when translating in Twig templates using the tag.
Tip
If you need to use the percent character (%
) in a string, escape it by doubling it: {% trans %}Percent: %percent%%%{% endtrans %}
You can also specify the message domain and pass some additional variables:
{% trans with {'%name%': 'Fabien'} from "app" %}Hello %name%{% endtrans %}
{% trans with {'%name%': 'Fabien'} from "app" into "fr" %}Hello %name%{% endtrans %}
{% transchoice count with {'%name%': 'Fabien'} from "app" %}
{0} %name%, there are no apples|{1} %name%, there is one apple|]1,Inf[ %name%, there are %count% apples
{% endtranschoice %}
The trans
and transchoice
filters can be used to translate variable texts and complex expressions:
{{ message|trans }}
{{ message|transchoice(5) }}
{{ message|trans({'%name%': 'Fabien'}, "app") }}
{{ message|transchoice(5, {'%name%': 'Fabien'}, 'app') }}
Tip
Using the translation tags or filters have the same effect, but with one subtle difference: automatic output escaping is only applied to translations using a filter. In other words, if you need to be sure that your translated message is not output escaped, you must apply the raw
filter after the translation filter:
{# text translated between tags is never escaped #}
{% trans %}
<h3>foo</h3>
{% endtrans %}
{% set message = '<h3>foo</h3>' %}
{# strings and variables translated via a filter are escaped by default #}
{{ message|trans|raw }}
{{ '<h3>bar</h3>'|trans|raw }}
Tip
You can set the translation domain for an entire Twig template with a single tag:
{% trans_default_domain "app" %}
Note that this only influences the current template, not any "included" template (in order to avoid side effects).
The translator service is accessible in PHP templates through the translator
helper:
<?php echo $view['translator']->trans('Symfony is great') ?>
<?php echo $view['translator']->transChoice(
'{0} There are no apples|{1} There is one apple|]1,Inf[ There are %count% apples',
10,
array('%count%' => 10)
) ?>
Symfony looks for message files (i.e. translations) in the following default locations:
- the
app/Resources/translations
directory; - the
app/Resources/<bundle name>/translations
directory; - the
Resources/translations/
directory inside of any bundle.
The locations are listed here with the highest priority first. That is, you can override the translation messages of a bundle in any of the top 2 directories.
The override mechanism works at a key level: only the overridden keys need to be listed in a higher priority message file. When a key is not found in a message file, the translator will automatically fall back to the lower priority message files.
The filename of the translation files is also important: each message file must be named according to the following path: domain.locale.loader
:
- domain: An optional way to organize messages into groups (e.g.
admin
,navigation
or the defaultmessages
) - seeusing-message-domains
; - locale: The locale that the translations are for (e.g.
en_GB
,en
, etc); - loader: How Symfony should load and parse the file (e.g.
xlf
,php
,yml
, etc).
The loader can be the name of any registered loader. By default, Symfony provides many loaders, including:
xlf
: XLIFF file;php
: PHP file;yml
: YAML file.
The choice of which loader to use is entirely up to you and is a matter of taste. The recommended option is to use xlf
for translations. For more options, see component-translator-message-catalogs
.
Note
You can add other directories with the paths <reference-translator-paths>
option in the configuration:
# app/config/config.yml
framework:
translator:
paths:
- '%kernel.root_dir%/../translations'
<!-- app/config/config.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:framework="http://symfony.com/schema/dic/symfony"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-Instance"
xsi:schemaLocation="http://symfony.com/schema/dic/services
http://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/symfony
http://symfony.com/schema/dic/symfony/symfony-1.0.xsd"
>
<framework:config>
<framework:translator>
<framework:path>%kernel.root_dir%/../translations</framework:path>
</framework:translator>
</framework:config>
</container>
// app/config/config.php
$container->loadFromExtension('framework', array(
'translator' => array(
'paths' => array(
'%kernel.root_dir%/../translations',
),
),
));
Note
You can also store translations in a database, or any other storage by providing a custom class implementing the Symfony\\Component\\Translation\\Loader\\LoaderInterface
interface. See the dic-tags-translation-loader
tag for more information.
Caution
Each time you create a new translation resource (or install a bundle that includes a translation resource), be sure to clear your cache so that Symfony can discover the new translation resources:
$ php bin/console cache:clear
Imagine that the user's locale is fr_FR
and that you're translating the key Symfony is great
. To find the French translation, Symfony actually checks translation resources for several locales:
- First, Symfony looks for the translation in a
fr_FR
translation resource (e.g.messages.fr_FR.xlf
); - If it wasn't found, Symfony looks for the translation in a
fr
translation resource (e.g.messages.fr.xlf
); - If the translation still isn't found, Symfony uses the
fallbacks
configuration parameter, which defaults toen
(see Configuration).
Note
When Symfony doesn't find a translation in the given locale, it will add the missing translation to the log file. For details, see reference-framework-translator-logging
.
Translating happens based on the user's locale. Read /translation/locale
to learn more about how to handle it.
The translation of database content should be handled by Doctrine through the Translatable Extension or the Translatable Behavior (PHP 5.4+). For more information, see the documentation for these libraries.
When you work with many translation messages in different languages, it can be hard to keep track which translations are missing and which are not used anymore. Read /translation/debug
to find out how to identify these messages.
With the Symfony Translation component, creating an internationalized application no longer needs to be a painful process and boils down to just a few basic steps:
- Abstract messages in your application by wrapping each in either the
Symfony\\Component\\Translation\\Translator::trans
orSymfony\\Component\\Translation\\Translator::transChoice
methods (learn about this in/components/translation/usage
); - Translate each message into multiple locales by creating translation message files. Symfony discovers and processes each file because its name follows a specific convention;
- Manage the user's locale, which is stored on the request, but can also be set on the user's session.
/translation/*