Doctrine ParamConverter using info of related Entities - php

Question

I have in Symfony a Entity of Post. That project has translations, stored in PostTranslation.
Each Post has a slug that is different for each language.
The code looks looks like:
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\ParamConverter;
/**
* #I18nDoctrine
* #Route("/blog/{slug}")
* #ParamConverter("post", class="SensioBlogBundle:Post")
*/
public function showAction(Post $post)
{
}
But how can I do a findOneBy('slug') kind of search? Because it is stored in the related Entity.

Answer 1

I guess besides slug property your PostTranslation entity stores some sort of language/locale, e.g. locale property, am I right? I also guess that your website is interlocalized based on some parameter stored in URL (different (sub)domain, query string parameter, path prefix - it's irrelevant), right?
There are at least three solutions that solve your problem:
Abandon the use of ParamConverter and do everything by yourself.
Override DoctrineParamConverter from SensionFrameworkExtraBundle and add support for finding by slug and locale for Post class. I would also suggest creating a little bit more robust solution:
Create Translatable interface that defines getTranslations() and setTranslations() methods and apply it to your Post class.
In your CustomDoctrineParamConverter check whether requested class implements this interface, if so, it means that you're going to search entity based on its translation, that is locale and some locale-unique property.
Now you need some way, to get the name of this locale-unique property. You could create another interface for your PostTranslation class that will define a single method, something like getLocaleIdentifier/UniqueProperty that for PostTranslation will return "slug".
If you know, that you need to find a Post property, based on locale and slug property from its translations assocation you can quite easily create DQL query to do that.
ParamConverter annotation has repository_method property that allows you to use custom method from PostRepository which should retrieve Post entity. The only problem is that built-in DoctrineParamConverter will pass only slug parameter to this method. Your repository will have to informed about current locale in some way. This could be achieved in many different ways, here's one of them:
Create LocaleAware interface with a single method setLocale($locale).
Implement that interface in PostRepository
Create event listener that listens for kernel.request event:
Iterate through all Doctrine's repositories.
Check if given repository implements LocaleAware interface.
Inject request's _locale attribute into repository.