translatable.md 19 KB
Translatable behavior extension for Doctrine 2
Translatable behavior offers a very handy solution for translating specific record fields in diferent languages. Further more, it loads the translations automatically for a locale currently used, which can be set to Translatable Listener on it`s initialization or later for other cases through the Entity itself
Features:
- Automatic storage of translations in database
- ORM and ODM support using same listener
- Automatic translation of Entity or Document fields then loaded
- ORM query can use hint to translate all records without issuing additional queries
- Can be nested with other behaviors
- Annotation, Yaml and Xml mapping support for extensions
2011-10-08
- Thanks to @acasademont Translatable now does not store translations for default locale. It is always left as original record value. So be sure you do not change your default locale per project or per data migration. This way it is more rational and unnecessary to store it additionaly in translation table.
Update 2011-04-21
- Implemented multiple translation persistense through repository
Update 2011-04-16
- Made an ORM query hint to hook into any select type query, which will join the translations and let you filter, order or search by translated fields directly. It also will translate all selected collections or simple components without issuing additional queries. It also supports translation fallbacks
- For performance reasons, translation fallbacks are disabled by default
Update 2011-04-04
- Made single listener, one instance can be used for any object manager and any number of them
Notice list:
- You can test live on this blog
- Public Translatable repository is available on github
- Using other extensions on the same Entity fields may result in unexpected way
- May inpact your application performace since it does an additional query for translation
- Last update date: 2011-10-08
Portability:
- Translatable is now available as Bundle ported to Symfony2 by Christophe Coevoet, together with all other extensions
This article will cover the basic installation and functionality of Translatable behavior
Content:
- Including the extension
- Attaching the Translation Listener
- Entity example
- Document example
- Yaml mapping example
- Xml mapping example
- Basic usage examples
- Persisting multiple translations
- Using ORM query hint
- Advanced usage examples
Setup and autoloading {#including-extension}
If you using the source from github repository, initial directory structure for the extension library should look like this:
...
/DoctrineExtensions
/lib
/Gedmo
/Exception
/Loggable
/Mapping
/Sluggable
/Timestampable
/Translatable
/Tree
/tests
...
...
First of all we need to setup the autoloading of extensions:
$classLoader = new \Doctrine\Common\ClassLoader('Gedmo', "/path/to/library/DoctrineExtensions/lib");
$classLoader->register();
This behavior requires an additional metadata path to be specified in order to have a translation table and translation Entity or Document available. To configure it correctly you need to add new annotation driver into driver chain with a specific location and namespace
Translation metadata Annotation driver mapped into driver chain:
$chainDriverImpl = new \Doctrine\ORM\Mapping\Driver\DriverChain();
$yourDefaultDriverImpl = new \Doctrine\ORM\Mapping\Driver\YamlDriver('/yml/mapping/files');
$translatableDriverImpl = $doctrineOrmConfig->newDefaultAnnotationDriver(
'/path/to/library/DoctrineExtensions/lib/Gedmo/Translatable/Entity' // Document for ODM
);
$chainDriverImpl->addDriver($yourDefaultDriverImpl, 'Entity');
$chainDriverImpl->addDriver($translatableDriverImpl, 'Gedmo\Translatable');
$doctrineOrmConfig->setMetadataDriverImpl($chainDriverImpl);
Notice: there can be many annotation drivers in driver chain
Notice: Translation Entity or Document is required for storing all translations.
If you need a translation table per single Entity or Document, we will cover how to setup it later
Attaching the Translation Listener to the event manager {#event-listener}
To attach the Translation Listener to your event system and to set the translation locale to be used in global scope for all Entities or Documents:
$evm = new \Doctrine\Common\EventManager();
// ORM and ODM
$translatableListener = new \Gedmo\Translatable\TranslationListener();
$translatableListener->setTranslatableLocale('en_us');
// in real world app the locale should be loaded from session, example:
// Session::getInstance()->read('locale');
$evm->addEventSubscriber($translatableListener);
// now this event manager should be passed to entity manager constructor
Translatable annotations:
- @Gedmo\Mapping\Annotation\Translatable it will translate this field
- @Gedmo\Mapping\Annotation\TranslationEntity(class="my\class") it will use this class to store translations generated
- @Gedmo\Mapping\Annotation\Locale or @Gedmo\Mapping\Annotation\Language this will identify this column as locale or language used to override the global locale
Translatable Entity example: {#entity}
Notice: that Translatable interface is not necessary, except in cases there you need to identify entity as being Translatable. The metadata is loaded only once then cache is activated
namespace Entity;
use Gedmo\Mapping\Annotation as Gedmo;
use Doctrine\ORM\Mapping as ORM;
use Gedmo\Translatable\Translatable;
/**
* @ORM\Table(name="articles")
* @ORM\Entity
*/
class Article implements Translatable
{
/** @ORM\Id @ORM\GeneratedValue @ORM\Column(type="integer") */
private $id;
/**
* @Gedmo\Translatable
* @ORM\Column(name="title", type="string", length=128)
*/
private $title;
/**
* @Gedmo\Translatable
* @ORM\Column(name="content", type="text")
*/
private $content;
/**
* @Gedmo\Locale
* Used locale to override Translation listener`s locale
* this is not a mapped field of entity metadata, just a simple property
*/
private $locale;
public function getId()
{
return $this->id;
}
public function setTitle($title)
{
$this->title = $title;
}
public function getTitle()
{
return $this->title;
}
public function setContent($content)
{
$this->content = $content;
}
public function getContent()
{
return $this->content;
}
public function setTranslatableLocale($locale)
{
$this->locale = $locale;
}
}
Translatable Document example: {#document}
namespace Document;
use Gedmo\Mapping\Annotation as Gedmo;
use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;
use Gedmo\Translatable\Translatable;
/**
* @ODM\Document(collection="articles")
*/
class Article implements Translatable
{
/** @ODM\Id */
private $id;
/**
* @Gedmo\Translatable
* @ODM\String
*/
private $title;
/**
* @Gedmo\Translatable
* @ODM\String
*/
private $content;
/**
* @Gedmo\Locale
* Used locale to override Translation listener`s locale
* this is not a mapped field of entity metadata, just a simple property
*/
private $locale;
public function getId()
{
return $this->id;
}
public function setTitle($title)
{
$this->title = $title;
}
public function getTitle()
{
return $this->title;
}
public function setContent($content)
{
$this->content = $content;
}
public function getContent()
{
return $this->content;
}
public function setTranslatableLocale($locale)
{
$this->locale = $locale;
}
}
Yaml mapping example {#yaml}
Yaml mapped Article: /mapping/yaml/Entity.Article.dcm.yml
---
Entity\Article:
type: entity
table: articles
gedmo:
translation:
locale: localeField
# using specific personal translation class:
# entity: Translatable\Fixture\CategoryTranslation
id:
id:
type: integer
generator:
strategy: AUTO
fields:
title:
type: string
length: 64
gedmo:
- translatable
content:
type: text
gedmo:
- translatable
Xml mapping example {#xml}
<?xml version="1.0" encoding="UTF-8"?>
<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping"
xmlns:gedmo="http://gediminasm.org/schemas/orm/doctrine-extensions-mapping">
<entity name="Mapping\Fixture\Xml\Translatable" table="translatables">
<id name="id" type="integer" column="id">
<generator strategy="AUTO"/>
</id>
<field name="title" type="string" length="128">
<gedmo:translatable/>
</field>
<field name="content" type="text">
<gedmo:translatable/>
</field>
<gedmo:translation entity="Gedmo\Translatable\Entity\Translation" locale="locale"/>
</entity>
</doctrine-mapping>
Basic usage examples: {#basic-examples}
Currently a global locale used for translations is "en_us" which was set in TranslationListener globaly. To save article with its translations:
$article = new Entity\Article;
$article->setTitle('my title in en');
$article->setContent('my content in en');
$em->persist($article);
$em->flush();
This inserted an article and inserted the translations for it in "en_us" locale only if en_us is not the default locale in case if default locale matches current locale - it uses original record value as translation
Now lets update our article in diferent locale:
// first load the article
$article = $em->find('Entity\Article', 1 /*article id*/);
$article->setTitle('my title in de');
$article->setContent('my content in de');
$article->setTranslatableLocale('de_de'); // change locale
$em->persist($article);
$em->flush();
This updated an article and inserted the translations for it in "de_de" locale To see and load all translations of Translatable Entity:
// reload in different language
$article = $em->find('Entity\Article', 1 /*article id*/);
$article->setLocale('ru_ru');
$em->refresh($article);
$article = $em->find('Entity\Article', 1 /*article id*/);
$repository = $em->getRepository('Gedmo\Translatable\Entity\Translation');
$translations = $repository->findTranslations($article);
/* $translations contains:
Array (
[de_de] => Array
(
[title] => my title in de
[content] => my content in de
)
[en_us] => Array
(
[title] => my title in en
[content] => my content in en
)
)*/
As far as our global locale is now "en_us" and updated article has "de_de" values. Lets try to load it and it should be translated in English
$article = $em->getRepository('Entity\Article')->find(1/* id of article */);
echo $article->getTitle();
// prints: "my title in en"
echo $article->getContent();
// prints: "my content in en"
Persisting multiple translations {#multi-translations}
Usually it is more convinient to persist more translations when creating or updating a record. Translatable allows to do that through translation repository. All additional translations will be tracked by listener and when the flush will be executed, it will update or persist all additional translations.
Notice: these translations will not be processed as ordinary fields of your object, in case if you translate a slug additional translation will not know how to generate the slug, so the value as an additional translation should be processed when creating it.
Example of multiple translations:
// persisting multiple translations, assume default locale is EN
$repository = $em->getRepository('Gedmo\\Translatable\\Entity\\Translation');
// it works for ODM also
$article = new Article;
$article->setTitle('My article en');
$article->setContent('content en');
$repository->translate($article, 'title', 'de', 'my article de')
->translate($article, 'content', 'de', 'content de')
->translate($article, 'title', 'ru', 'my article ru')
->translate($article, 'content', 'ru', 'content ru');
$em->persist($article);
$em->flush();
Using ORM query hint {#orm-query-hint}
By default, behind the scenes, when you load a record - translatable hooks into postLoad event and issues additional query to translate all fields. Imagine that when you load a collection, when it issues a lot of queries just to translate those fields. Also if you want to hydrate result as an array, it is not possible to hook any postLoad event since it is not an entity being hydrated. These are the main reason why TranslationWalker was born.
TranslationWalker uses a query hint to hook into any select type query, and when you execute the query, no matter which hydration method you use, it automatically joins the translations for all fields, so you could use ordering filtering or whatever you want on translations of the fields instead of original record fields.
And in result there is only one query for all this happyness.
If you use translation fallbacks it will be also in the same single query and during the hydration process it will replace the empty fields in case if they do not have a translation in currently used locale.
Now enough talking, here is an example:
$dql = "SELECT a, c, u FROM Article a "
. "LEFT JOIN a.comments c "
. "JOIN c.author u "
. "WHERE a.title LIKE '%translated_title%' "
. "ORDER BY a.title";
$query = $em->createQuery($dql);
// set the translation query hint
$query->setHint(
\Doctrine\ORM\Query::HINT_CUSTOM_OUTPUT_WALKER,
'Gedmo\\Translatable\\Query\\TreeWalker\\TranslationWalker'
);
$articles = $query->getResult(); // object hydration
$articles = $query->getArrayResult(); // array hydration
And even a subselect:
$subSelect = "SELECT a2.id FROM Article a2 "
. "WHERE a2.title LIKE '%something_translated%'";
$dql = "SELECT a, c, u FROM Article a "
. "LEFT JOIN a.comments c "
. "JOIN c.author u "
. "WHERE a.id IN ({$subSelect}) "
. "ORDER BY a.title";
$query = $em->createQuery($dql);
$query->setHint(
\Doctrine\ORM\Query::HINT_CUSTOM_OUTPUT_WALKER,
'Gedmo\\Translatable\\Query\\TreeWalker\\TranslationWalker'
);
$articles = $query->getResult(); // object hydration
Theres no need for any words anymore.. right? I recommend you to use it extensively since it is a way better performance, even in cases where you need to load single translated entity.
Notice: Even in COUNT select statements translations are joined to leave a
possibility to filter by translated field, if you do not need it, just do not set
the hint. Also take into account that it is not possibble to translate components
in JOIN WITH statement, example JOIN a.comments c WITH c.message LIKE '%will_not_be_translated%'
Notice: any find related method calls cannot hook this hint automagically, we will use a different approach when persister overriding feature will be available in Doctrine
Advanced examples: {#advanced-examples}
Default locale
In some cases we need a default translation as a fallback if record does not have a translation on globaly used locale. In that case Translation Listener takes the current value of Entity. So if default locale is specified and it matches the locale in which record is being translated - it will not create extra translation but use original values instead. If translation fallback is set to false it will fill untranslated values as blanks
To set the default locale:
$translationListener->setDefaultLocale('en_us');
To set translation fallback:
$translationListener->setTranslationFallback(true); // default is false
Note: Default locale should be set on the TranslationListener initialization once, since it can impact your current records if it will be changed. As it will not store extra record in translation table.
Translation Entity
In some cases if there are thousands of records or even more.. we would like to have a single table for translations of this Entity in order to increase the performance on translation loading speed. This example will show how to specify a diferent Entity for your translations by extending the mapped superclass.
ArticleTranslation Entity:
namespace Entity\Translation;
use Doctrine\ORM\Mapping as ORM;
use Gedmo\Translatable\Entity\AbstractTranslation;
/**
* @ORM\Table(name="article_translations", indexes={
* @ORM\index(name="article_translation_idx", columns={"locale", "objectClass", "foreign_key", "field"})
* })
* @ORM\Entity(repositoryClass="Gedmo\Translatable\Entity\Repository\TranslationRepository")
*/
class ArticleTranslation extends AbstractTranslation
{
/**
* All required columns are mapped through inherited superclass
*/
}
Notice: We specified the repository class to be used from extension. It is handy for specific methods common to the Translation Entity
Notice: This Entity will be used instead of default Translation Entity only if we specify a class annotation @Gedmo\TranslationEntity(class="my\translation\entity"):
use Doctrine\ORM\Mapping as ORM;
/**
* @ORM\Table(name="articles")
* @ORM\Entity
* @Gedmo\TranslationEntity(class="Entity\Translation\ArticleTranslation")
*/
class Article
{
// ...
}
Now all translations of Article will be stored and queried from specific table
Easy like that, any suggestions on improvements are very welcome