/**
* Defined by Zend_Validate_Interface
*
* Returns true if and only if $value contains only alphabetic and digit characters
*
* @param string $value
* @return boolean
*/
public function isValid($value)
{
$valueString = (string) $value;
$this->_setValue($valueString);
if ('' === $valueString) {
$this->_error(self::STRING_EMPTY);
return false;
}
if (null === self::$_filter) {
/**
* @see Zend_Filter_Alnum
*/
//require-once 'Dkplus/Filter/AlnumUnderline.php';
self::$_filter = new Dkplus_Filter_AlnumUnderline();
}
self::$_filter->setMeansEnglishAlphabet($this->_meansEnglishAlphabet);
self::$_filter->allowWhiteSpace = $this->allowWhiteSpace;
if ($valueString !== self::$_filter->filter($valueString)) {
$this->_error(self::NOT_ALNUM);
return false;
}
return true;
}
