Constraint relative to Locale parameter in Symfony2 - php

Question

I need to validate a form field against bad words dictionary (Array for example). So to do this I have to create a new Constraint + ConstraintValidator. It works great, the only problem I have is that I want to have different dictionaries for different locales.
Example:
namespace MyNameSpace\Category\MyFormBundle\Validator\Constraints;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
class ContainsNoBadWordsValidator extends ConstraintValidator
{
protected $badWordsEN = array('blabla');
protected $badWordsFR = array('otherblabla');
public function validate($value, Constraint $constraint)
{
if (in_array(strtolower($value), array_map('strtolower', $this->getBadWords()))) {
$this->context->addViolation($constraint->message, array('{{ value }}' => $value));
}
}
protected function getBadWords($locale = 'EN')
{
switch ($locale) {
case 'FR':
return $this->badWordsFR;
break;
default:
return $this->badWordsEN;
break;
}
}
}
So how do I pass the locale to Constraint? Or should I implement it differently?

Answer 1

The locale parameter is a member of the Request object.
However, the request object is not created all the time (eg. in a CLI application)
This solution allows you to decouple your validation from the request object, and let your validation to be easily unit-tested.
The LocaleHolder is a request-listener which will hold upon creation the %locale% parameter and then, switch to the Request locale when the event is triggered.
Note: The %locale% parameter is the default parameter defined in config.yml
Your validator must then get this LocaleHolder as a constructor parameter, in order to be aware of the current locale.
services.yml
Here, declare the two services you will need, the LocaleHolder and your validator.
services:
acme.locale_holder:
class: Acme\FooBundle\LocaleHolder
arguments:
- "%locale%"
tags:
-
name: kernel.event_listener
event: kernel.request
method: onKernelRequest
acme.validator.no_badwords:
class: Acme\FooBundle\Constraints\NoBadwordsValidator
arguments:
- #acme.locale_holder
tags:
-
name: validator.constraint_validator
alias: no_badwords
Acme\FooBundle\LocaleHolder
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
class LocaleHolder
{
protected $locale;
public function __construct($default = 'EN')
{
$this->setLocale($default);
}
public function onKernelRequest(GetResponseEvent $event)
{
$request = $event->getRequest();
$this->setLocale($request->getLocale());
}
public function getLocale()
{
return $this->locale;
}
public function setLocale($locale)
{
$this->locale = $locale;
}
}
Acme\FooBundle\Constraints
use Acme\FooBundle\LocaleHolder;
class ContainsNoBadwordsValidator extends ConstraintValidator
{
protected $holder;
public function __construct(LocaleHolder $holder)
{
$this->holder = $holder;
}
protected function getBadwords($locale = null)
{
$locale = $locale ?: $this->holder->getLocale();
// ...
}
}