Symfony2 form validation based on two fields

Question

I am currently developing a Website in which user may buy gift cards. I am using a three step form using the CraueFormFlow bundle and everything is concerning the steps. I a

Answer 1

This is how I've done this in my validation constraints, to check credit card validity with expiration month and year properties.

In this class, I check the value of expirationYear property and compare it with value of expirationMonth property got from contextObject.

/**
 * Method to validate
 * 
 * @param string                                  $value      Property value    
 * @param \Symfony\Component\Validator\Constraint $constraint All properties
 * 
 * @return boolean
 */
public function validate($value, Constraint $constraint)
{
    $date               = getdate();
    $year               = (string) $date['year'];
    $month              = (string) $date['mon'];

    $yearLastDigits     = substr($year, 2);
    $monthLastDigits    = $month;
    $otherFieldValue    = $this->context->getRoot()->get('expirationMonth')->getData();

    if (!empty($otherFieldValue) && ($value <= $yearLastDigits) && 
            ($otherFieldValue <= $monthLastDigits)) {
        $this->context->addViolation(
            $constraint->message,
            array('%string%' => $value)
        );            
        return false;            
    }

    return true;
}

Of course, you have to authorize class and properties constraints in your getTargets method, form the main constraint file.

/**
 * Get class constraints and properties
 * 
 * @return array
 */
public function getTargets()
{
    return array(self::CLASS_CONSTRAINT, self::PROPERTY_CONSTRAINT);
} 

Further explanations and complete tutorial here: http://creativcoders.wordpress.com/2014/07/19/symfony2-two-fields-comparison-with-custom-validation-constraints/