How to use Symfony2 Validation Constraint Callback with validation groups to validate a single property

PriceQuoteRequest.php

<?php

namespace Acme\AppBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Validator\Context\ExecutionContextInterface;

/**
 * PriceQuoteRequest
 *
 * @ORM\Table(name="pricequote")
 * @ORM\Entity
 *
 * @Assert\Callback(methods={"isGutterValid"}, groups={"flow_dormerRequest_step2"})
 */
class PriceQuoteRequest
{
    /**
     * @var integer $dormerInnerHeight
     *
     * @ORM\Column(name="h", type="float")
     * @Assert\NotBlank(groups={"flow_dormerRequest_step2"})
     * @Assert\Range(min="80", max="1000", groups={"flow_dormerRequest_step2"})
     */
    public $dormerInnerHeight;

    /**
     * @var boolean $dormerGutter
     *
     * @ORM\Column(name="gutter", type="boolean")
     *
     * @Assert\Type(type="boolean", groups={"flow_dormerRequest_step2"})
     * Assert\Callback(methods={"isGutterValid"}, groups={"flow_dormerRequest_step2"})
     */
    public $dormerGutter;

    /**
     * @ORM\OneToOne(targetEntity="Acme\AppBundle\Entity\GutterMaterial")
     *
     * Assert\Type(type="Acme\AppBundle\Entity\GutterMaterial", groups={"flow_dormerRequest_step2"})
     */
    public $dormerGutterMaterial;

    /**
     *
     * @param ExecutionContextInterface $context
     *
     * Assert\Callback(groups={"flow_dormerRequest_step2"})
     */
    public function isGutterValid(ExecutionContextInterface $context)
    {
        if ($this->getDormerGutter() === true && $this->getDormerGutterMaterial() === null) {
            $context->buildViolation('Gutter checked but no Material selected.')
                ->atPath('dormerGutter')
                ->addViolation();
        }
    }
}

RequestFunctionalTest.php

<?php

namespace Acme\AppBundle\Tests\Entity;

use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
use Symfony\Component\Validator\Validation;

class RequestFunctionalTest extends KernelTestCase
{
    /**
     * @var \Doctrine\ORM\EntityManager
     */
    private $em;

    /**
     * {@inheritDoc}
     */
    public function setUp()
    {
        self::bootKernel();
        $this->em = static::$kernel->getContainer()
            ->get('doctrine')
            ->getManager()
        ;
    }

    public function testDormerGutterValidator()
    {
        $priceQuoteRequest = new PriceQuoteRequest();

        $priceQuoteRequest->setDormerGutter(true);

        // Validating on single property will not call "isGutterValid" Callback, exptected only 1 error otherwise
        // $violationList = $this->getValidator()->validateProperty($priceQuoteRequest, 'dormerGutter', array('flow_dormerRequest_step2'));

        // Validating full object will call "isGutterValid" but return all errors resp. > 1
        $violationList = $this->getValidator()->validate($priceQuoteRequest, array('flow_dormerRequest_step2'));

        dump($violationList);

        $this->assertEquals(1, count($violationList));
    }
}

If DormerGutter is set to true (resp. checked in form) a DormerGutterMaterial has to be selected.

The isGutterValid method is supposed to check this and otherwise point the violation to the DormerGutter field:

 if ($this->getDormerGutter() === true && $this->getDormerGutterMaterial() === null) {
    $context->buildViolation('Gutter checked but no Material selected.')
        ->atPath('dormerGutter')
        ->addViolation();
} 

The Test sets the DormerGutter to true but selects no DormerGutterMaterial.
Validating on the property DormerGutter I expect to get that 1 error returned by the isGutterValid Callback.

Instead it will return 0 errors because calling validateProperty on a single property DOES NOT CALL the "global" Callback for the entire object resp. class.

Instead I can validate the complete object. This will indeed call the isGutterValid method.
It will return at least 2 errors since this also validates all the other properties e.g. dormerInnerHeight
Unfortunately - in my use case - I only want that 1 error returned.

Is there a way to point a Callback to a single property only enabling me to call the validateProperty method and still fire the Callback?

The alternative / workaround will of course be the usage of the Expression Constraint:

    /**
     * @var boolean $dormerGutter
     *
     * @ORM\Column(name="gutter", type="boolean")
     *
     * @Assert\Type(type="boolean", groups={"flow_dormerRequest_step2"})
     * @Assert\Expression(
     *  "this.getDormerGutterMaterial() !== null or this.getDormerGutter() == 0",
     *  message="Gutter checked but no Material selected.",
     *  groups={"flow_dormerRequest_step2"}
     * )
     */
    public $dormerGutter; 

Ps.: All validation groups are successfully linked to flow_dormerRequest_step2.

The question on stackoverflow:
http://stackoverflow.com/questions/28071496/how-to-use-symfony2-validation-constraint-callback-with-validation-groups-to-val

A smart workaround if I will HAVE TO use the validate method instead of validateProperty is to reduce the number of expected errors by using a custom validation group:

/**
* PriceQuoteRequest
*
* @ORM\Table(name="pricequote")
* @ORM\Entity
*
* @Assert\Callback(methods={"isGutterValid"}, groups={"dormerGutter"})
*/ 

And change the call in the Test class:

$violationList = $this->getValidator()->validate($priceQuoteRequest, array('dormerGutter'));

Thanks @bjo3rnf !