All CAPTCHA adapter implement
Zend_Captcha_Adapter
, which looks like the following:
interface Zend_Captcha_Adapter extends Zend_Validate_Interface { public function generate(); public function render(Zend_View $view, $element = null); public function setName($name); public function getName(); public function getDecorator(); // Additionally, to satisfy Zend_Validate_Interface: public function isValid($value); public function getMessages(); public function getErrors(); }
The name setter and getter are used to specify and retrieve the
CAPTCHA identifier. getDecorator()
can be used to specify a
Zend_Form
decorator either by name or returning an actual decorator
object. The most interesting methods are generate()
and render()
. generate()
is used to create the
CAPTCHA token. This process typically will store the token in the
session so that you may compare against it in subsequent requests.
render()
is used to render the information that represents
the CAPTCHA- be it an image, a figlet, a logic problem, or some other CAPTCHA.
A typical use case might look like the following:
// Creating a Zend_View instance $view = new Zend_View(); // Originating request: $captcha = new Zend_Captcha_Figlet(array( 'name' => 'foo', 'wordLen' => 6, 'timeout' => 300, )); $id = $captcha->generate(); echo $captcha->render($view); // On subsequent request: // Assume captcha setup as before, and $value is the submitted value: if ($captcha->isValid($_POST['foo'], $_POST)) { // Validated! }