/**
* Check chars allowed.
*/
protected function checkCharsAllowed()
{
$c = strlen($this->text);
// Special case, if we have 10 digits, the last one can be X
if ($c === 10) {
if (array_search($this->text[9], $this->keys) === false && $this->text[9] !== 'X') {
throw new BCGParseException('isbn', 'The character \'' . $this->text[9] . '\' is not allowed.');
}
// Drop the last char
$this->text = substr($this->text, 0, 9);
}
return parent::checkCharsAllowed();
}