Zend_Validate_CreditCard allows you to validate if a given value
could be a credit card number.
A creditcard 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_Validate_CreditCard
simply verifies that the credit card number provided is well-formed.
For those cases where you have a service that can perform comprehensive verification,
Zend_Validate_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:
-
American Express
China UnionPay
Diners Club Card Blanche
Diners Club International
Diners Club US & Canada
Discover Card
JCB
Laser
Maestro
MasterCard
Solo
Visa
Visa Electron
Invalid institutes
The institutes Bankcard and Diners Club enRoute do not exist anymore. Therefore they are treated as invalid.
Switch has been rebranded to Visa and is therefore also treated as invalid.
The following options are supported for Zend_Validate_CreditCard:
service: A callback to an online service which will additionally be used for the validation.
type: The type of creditcard which will be validated. See the below list of institutes for details.
There are several credit card institutes which can be validated by
Zend_Validate_CreditCard. Per default, all known institutes will
be accepted. See the folowing example:
<?php
$valid = new Zend_Validate_CreditCard();
if ($valid->isValid($input)) {
// input appears to be valid
} else {
// input is invalid
}
The above example would validate against all known credit card institutes.
Sometimes it is necessary to accept only defined credit card institutes instead of all;
e.g., when you have a webshop which accepts only Visa and American Express cards.
Zend_Validate_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:
<?php
$valid = new Zend_Validate_CreditCard(
Zend_Validate_CreditCard::AMERICAN_EXPRESS
);
When you want to allow multiple institutes, then you can provide them as array:
<?php
$valid = new Zend_Validate_CreditCard(array(
Zend_Validate_CreditCard::AMERICAN_EXPRESS,
Zend_Validate_CreditCard::VISA
));
And as with all validators, you can also pass an associative array of options or an
instance of Zend_Config. In this case you have to provide the
institutes with the type array key as simulated here:
<?php
$valid = new Zend_Validate_CreditCard(array(
'type' => array(Zend_Validate_CreditCard::AMERICAN_EXPRESS)
));
Table 168. Constants for credit card institutes
| Institute | Constant |
|---|---|
| American Express | AMERICAN_EXPRESS |
| China UnionPay | UNIONPAY |
| Diners Club Card Blanche | DINERS_CLUB |
| Diners Club International | DINERS_CLUB |
| Diners Club US & Canada | DINERS_CLUB_US |
| Discover Card | DISCOVER |
| JCB | JCB |
| Laser | LASER |
| Maestro | MAESTRO |
| MasterCard | MASTERCARD |
| Solo | SOLO |
| Visa | VISA |
| Visa Electron | VISA |
You can also set or add institutes afterward instantiation by using the methods
setType(), addType() and
getType().
<?php
$valid = new Zend_Validate_CreditCard();
$valid->setType(array(
Zend_Validate_CreditCard::AMERICAN_EXPRESS,
Zend_Validate_CreditCard::VISA
));
Default institute
When no institute is given at initiation then ALL will be
used, which sets all institutes at once.
In this case the usage of addType() is useless because all
institutes are already added.
As said before Zend_Validate_CreditCard will only validate
the credit card number. Fortunately, some institutes provide online
APIs which can validate a credit card number by using algorithms
which are not available to the public. Most of these services are paid services.
Therefore, this check is deactivated per default.
When you have access to such an API, then you can use it as an addon
for Zend_Validate_CreditCard and increase the security of the
validation.
To do so, you simply need to give a callback which will be called when the generic validation has passed. This prevents the API from being called for invalid numbers, which increases the performance of the application.
setService() sets a new service, and
getService() returns the set service. As a configuration
option,
you can give the array key 'service' at initiation. For details
about possible options take a look into Callback.
<?php
// Your service class
class CcService
{
public function checkOnline($cardnumber, $types)
{
// some online validation
}
}
// The validation
$service = new CcService();
$valid = new Zend_Validate_CreditCard(Zend_Validate_CreditCard::VISA);
$valid->setService(array($service, 'checkOnline'));
As you can see the callback method will be called with the creditcard number as the first parameter, and the accepted types as the second parameter.