/**
* Defined by Zend_Validate_Interface
*
* Returns true if and only if $value contains a valid Eividencial namber message
*
* @param string $value
* @return boolean
*/
public function isValid($value)
{
$this->_setValue($value);
if (null === self::$_filter) {
/**
* @see Zend_Filter_Digits
*/
require_once 'Zend/Filter/Digits.php';
self::$_filter = new Zend_Filter_Digits();
}
$valueFiltered = self::$_filter->filter($value);
$length = strlen($valueFiltered);
if ($length != 10) {
$this->_error(self::LENGTH);
return false;
}
$mod = 11;
$sum = 0;
$weights = array(6, 5, 7, 2, 3, 4, 5, 6, 7);
preg_match_all("/\\d/", $valueFiltered, $digits);
$valueFilteredArray = $digits[0];
foreach ($valueFilteredArray as $digit) {
$weight = current($weights);
$sum += $digit * $weight;
next($weights);
}
if (($sum % $mod == 10 ? 0 : $sum % $mod) != $valueFilteredArray[$length - 1]) {
$this->_error(self::CHECKSUM, $valueFiltered);
return false;
}
return true;
}
