Injecting Symfony services into Behat PageObjects

BasePage.php

namespace Kaliop\AProject\PageObjects\Pages;

use SensioLabs\Behat\PageObjectExtension\PageObject\Page;
use Behat\Mink\Session;
use SensioLabs\Behat\PageObjectExtension\PageObject\Factory;

abstract class BasePage extends Page
{
    protected $aService;

    public function __construct(Session $session, Factory $factory, array $parameters = array())
    {
        parent::__construct($session, $factory, $parameters);

        // The parameters arriving here come from behat.yml, but the Factory class from KTools adds some services
        $this->aService = $parameters['services']['a_service'];
    }

behat.yml

    extensions:
        Kaliop\Behat\KToolsExtension: ~
        SensioLabs\Behat\PageObjectExtension:
            factory:
                id: kaliop.ktools_extension.page_factory.serviceaware

ServiceAwareFactory

namespace Kaliop\Behat\KToolsExtension\PageObject\Factory;

use SensioLabs\Behat\PageObjectExtension\PageObject\Factory\DefaultFactory;
use Behat\Mink\Mink;
use SensioLabs\Behat\PageObjectExtension\PageObject\Factory\ClassNameResolver;

/**
 * Allows us to pass Symfony services into PageObjects
 */
class ServiceAwareFactory extends DefaultFactory
{
    public function __construct(Mink $mink, ClassNameResolver $classNameResolver, array $pageParameters, $services = array())
    {
        $pageParameters['services'] = $services;

        parent::__construct($mink, $classNameResolver, $pageParameters);
    }
}

services.yml

services:
    kaliop.ktools_extension.page_factory.serviceaware:
        class: "%kaliop.ktools_extension.page_factory.serviceaware.class%"
        arguments: [@mink, @sensio_labs.page_object_extension.class_name_resolver, %sensio_labs.page_object_extension.page_factory.page_parameters%, {a_service: @kaliop.ktools_extension.a.service}]
    kaliop.ktools_extension.a.service
        etc: ...