Luhn

Luhn

This constraint is used to ensure that a credit card number passes the Luhn algorithm. It is useful as a first step to validating a credit card: before communicating with a payment gateway.

Applies to property or method
Options
Class Luhn
Validator LuhnValidator

Basic Usage

To use the Luhn validator, simply apply it to a property on an object that will contain a credit card number.

  • Annotations
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    // src/AppBundle/Entity/Transaction.php
    namespace AppBundle\Entity;
    
    use Symfony\Component\Validator\Constraints as Assert;
    
    class Transaction
    {
        /**
         * @Assert\Luhn(message = "Please check your credit card number.")
         */
        protected $cardNumber;
    }
    
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    # src/AppBundle/Resources/config/validation.yml
    AppBundle\Entity\Transaction:
        properties:
            cardNumber:
                - Luhn:
                    message: Please check your credit card number.
    
  • XML
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    <!-- src/AppBundle/Resources/config/validation.xml -->
    <?xml version="1.0" encoding="UTF-8" ?>
    <constraint-mapping xmlns="http://symfony.com/schema/dic/constraint-mapping"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://symfony.com/schema/dic/constraint-mapping http://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd">
    
        <class name="AppBundle\Entity\Transaction">
            <property name="cardNumber">
                <constraint name="Luhn">
                    <option name="message">Please check your credit card number.</option>
                </constraint>
            </property>
        </class>
    </constraint-mapping>
    
  • PHP
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    // src/AppBundle/Entity/Transaction.php
    namespace AppBundle\Entity;
    
    use Symfony\Component\Validator\Mapping\ClassMetadata;
    use Symfony\Component\Validator\Constraints as Assert;
    
    class Transaction
    {
        protected $cardNumber;
    
        public static function loadValidatorMetadata(ClassMetadata $metadata)
        {
            $metadata->addPropertyConstraint('cardNumber', new Assert\Luhn(array(
                'message' => 'Please check your credit card number',
            )));
        }
    }
    

Available Options

message

type: string default: Invalid card number.

The default message supplied when the value does not pass the Luhn check.

payload

type: mixed default: null

This option can be used to attach arbitrary domain-specific data to a constraint. The configured payload is not used by the Validator component, but its processing is completely up to you.

For example, you may want to use several error levels to present failed constraints differently in the front-end depending on the severity of the error.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.