CreditCard Validator

Zend\Validator\CreditCard allows you to validate if a given value could be a credit card number.

A credit card contains several items of metadata, including a hologram, account number, logo, expiration date, security code, and the card holder name. The algorithms for verifying the combination of metadata are only known to the issuing company, and should be verified with them for purposes of payment. However, it's often useful to know whether or not a given number actually falls within the ranges of possible numbers prior to performing such verification, and, as such, Zend\Validator\CreditCard verifies that the credit card number provided is well-formed.

For those cases where you have a service that can perform comprehensive verification, Zend\Validator\CreditCard also provides the ability to attach a service callback to trigger once the credit card number has been deemed valid; this callback will then be triggered, and its return value will determine overall validity.

The following issuing institutes are accepted:

Invalid institutes

The institutes Bankcard and Diners Club enRoute no longer exist, and are treated as invalid.

Switch has been rebranded to Visa and is therefore also treated as invalid.

Supported options

The following options are supported for Zend\Validator\CreditCard:

Basic usage

There are several credit card institutes which can be validated by Zend\Validator\CreditCard. Per default, all known institutes will be accepted. See the following example:

$valid = new Zend\Validator\CreditCard();
if ($valid->isValid($input)) {
    // input appears to be valid
} else {
    // input is invalid
}

The above example would validate against all known credit card institutes.

Accepting only specific credit cards

Sometimes it is necessary to accept only specific credit card institutes instead of all; e.g., when you have a webshop which accepts only Visa and American Express cards. Zend\Validator\CreditCard allows you to do exactly this by limiting it to exactly these institutes.

To use a limitation you can either provide specific institutes at initiation, or afterwards by using setType(). Each can take several arguments.

You can provide a single institute:

use Zend\Validator\CreditCard;

$valid = new CreditCard(CreditCard::AMERICAN_EXPRESS);

When you want to allow multiple institutes, then you can provide them as array:

use Zend\Validator\CreditCard;

$valid = new CreditCard([
    CreditCard::AMERICAN_EXPRESS,
    CreditCard::VISA
]);

And, as with all validators, you can also pass an associative array of options or an instance of Traversable. In this case you have to provide the institutes with the type array key as demostrated here:

use Zend\Validator\CreditCard;

$valid = new CreditCard([
    'type' => [CreditCard::AMERICAN_EXPRESS]
]);

You can also manipulate institutes after instantiation by using the methods setType(), addType(), and getType().

use Zend\Validator\CreditCard;

$valid = new CreditCard();
$valid->setType([
    CreditCard::AMERICAN_EXPRESS,
    CreditCard::VISA
]);

Default institute

When no institute is given at initiation then ALL will be used, which sets all institutes at once.

In this case the usage of addType() is useless because all institutes are already added.

Validation using APIs

As said before Zend\Validator\CreditCard will only validate the credit card number. Fortunately, some institutes provide online APIs which can validate a credit card number by using algorithms which are not available to the public. Most of these services are paid services. Therefore, this check is deactivated per default.

When you have access to such an API, then you can use it as an add on for Zend\Validator\CreditCard and increase the security of the validation.

To do so, provide a callback to invoke when generic validation has passed. This prevents the API from being called for invalid numbers, which increases the performance of the application.

setService() sets a new service, and getService() returns the set service. As a configuration option, you can give the array key service at instantiatio. For details about possible options, read the Callback validator documentation.

use Zend\Validator\CreditCard;

// Your service class
class CcService
{
    public function checkOnline($cardnumber, $types)
    {
        // some online validation
    }
}

// The validation
$service = new CcService();
$valid   = new CreditCard(CreditCard::VISA);
$valid->setService([$service, 'checkOnline']);

The callback method will be called with the credit card number as the first parameter, and the accepted types as the second parameter.