/**
* The Command abstraction.
* In this case the implementation must return a result,
* sometimes it only has side effects.
*/
interface Validator
{
/**
* The method could have any parameters.
* @param mixed
* @return boolean
*/
public function isValid($value);
}
/**
* ConcreteCommand.
*/
class MoreThanZeroValidator implements Validator
{
public function isValid($value)
{
return $value > 0;
}
}
/**
* ConcreteCommand.
*/
class EvenValidator implements Validator
{
public function isValid($value)
{
return $value % 2 == 0;
}
}
/**
* The Invoker. An implementation could store more than one
* Validator if needed.
*/
class ArrayProcessor
{
protected $_rule;
public function __construct (Validator $rule)
{
$this->_rule = $rule;
}
public function process
(array $numbers) {
foreach ($numbers as $n) {
if ($this->_rule->IsValid($n)) {
echo $n, "\n";
}
}
}
}
// Client code
$processor = new ArrayProcessor(new EvenValidator());
$processor->process(array(1, 20, 18, 5, 0, 31, 42));