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 am able to validate every simple Assert (like not blank, email, repeated fields, etc) but I am facing the situation where, user may select 0 gift cards and proceed to the next page.

The users may choose the quantity of giftcards they want to buy using two separate : one for 25$ gift cards and one for 50$ gift cards. So I can't just put a validator saying "value 0 is not allowed". The validator must prevent a user from leaving the quantity "0" in both amount (25$ and 50$).

Does anyone know how to make a custom validation looking for the values in two fields?

Thanks in advance!

Solution 1

You have many solutions for this.

The easiest one is to add a Callback constraint to your model class.

Another way to do it would be to create your custom constraint and its associated validator. You have a cookbook explaining how to create a custom validation constrain. This is the best approach to do it.

As your constraint does not apply to a property but to a class, you must specify it overriding the the ->getTargets() method of your constraint class:

class MyConstraint extends Constraint
{
    // ...

    public function getTargets()
    {
        return Constraint::CLASS_CONSTRAINT;
    }
}

So the value passed as $value argument of the ->isValid() method will contain values of the whole class and not only of a single property.

Solution 2

When you don't have a data class attached to your form you can implement dependent constraints in forms like this:

    $startRangeCallback = function ($object, ExecutionContextInterface $context) use ($form)
    {
        $data = $form->getData();
        $rangeEnd = $data['range_end'];
        if($object && $rangeEnd){
            if ($object->getTimestamp() > $rangeEnd->getTimestamp()) {
                $context->addViolation('Start date should be before end date!', array(), null);
            }
        }

    };

    $form->add('range_start', 'bootstrap_datepicker', array(
            'format' => 'dd-MM-yyyy',
            'required' => false,
            'attr' => array('class' => "col-xs-2"),
            'calendar_weeks' => true,
            'clear_btn' => true,
            'constraints' => array(
                new Callback(array($startRangeCallback)),
            )
        )
    );

    $form->add('range_end', 'bootstrap_datepicker', array(
            'format' => 'dd-MM-yyyy',
            'required' => false,
            'attr' => array('class' => "col-xs-2"),
            'calendar_weeks' => true,
            'clear_btn' => true,

        )
    );

Solution 3

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/

Solution 4

Use Regular expression inorder to prevent Zero

In your Entity class write down the below override function , and specify your property which you need to validate.

The below example is for validating a pincode ,here in pincode field I admit only numbers 0-9 combinations upto 10 digits .

" ^\d+$ " this is the regular expression I used to prevent other characters.

For overriding this function you must include the below classes

use Symfony\Component\Validator\Mapping\ClassMetadata;// for overriding function loadValidatorMetadata()

use Symfony\Component\Validator\Constraints\NotBlank;// for notblank constrain

use Symfony\Component\Validator\Constraints\Email;//for email constrain

use Symfony\Component\Validator\Constraints\MinLength;// for minimum length

use Symfony\Component\Validator\Constraints\MaxLength; // for maximum length

use Symfony\Component\Validator\Constraints\Choice; // for choice fields

use Symfony\Component\Validator\Constraints\Regex; // for regular expression



public static function loadValidatorMetadata(ClassMetadata $metadata)
    {
        $metadata->addPropertyConstraint('pincode', new NotBlank(array('message' => 'Does not blank')));
        $metadata->addPropertyConstraint('pincode', new Regex(array('pattern'=>'/^\d+$/','message' => 'must be number')));
        $metadata->addPropertyConstraint('pincode', new MaxLength(array('limit'=>'6','message' => 'must maximum 6 digits')));
        $metadata->addPropertyConstraint('pincode', new MinLength(array('limit'=>'6','message' => 'must minimum 6 digits')));


    }

Not forget these all must

included in your Entity class

that you have to validate. So in your case use a proper regular expression which does not permit '0'.

Happy coding

Solution 5

I'd suggest using Expression constraint. This constraint can be applied on form field or (preferably) in entity:

   /**
     * @var int
     * @Assert\Type(type="integer")
     */
    private $amountGiftCards25;

    /**
     * @var int
     * @Assert\Type(type="integer")
     * @Assert\Expression(expression="this.getAmountGiftCards25() > 0 or value > 0", message="Please choose amount of gift cards.")
     */
    private $amountGiftCards50;

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Comments

[Jean-Francois Hamelin]

Could you please explain me how to implement the callback constraint? I am looking at the Symfony2 doc and I don't quite know how to access the values I want to check in the [...]isValid() function.

[umpirsky]

Looks like it does not work when there is no data class (when you work with arrays).

[V-Light]

and what if i need to access entityManger too ?