RawLayout.php
protected function validateId($id, $fullCheck = false)
    {
        if (!$id) {
            throw new Exception\InvalidArgumentException('The item id must not be empty.');
        }
        if ($fullCheck) {
            if (!is_string($id)) {
                throw new Exception\UnexpectedTypeException($id, 'string', 'id');
            }
            if (!$this->isValidId($id)) {
                throw new Exception\InvalidArgumentException(
                    sprintf(
                        'The "%s" string cannot be used as the item id because it contains illegal characters. '
                        . 'The valid item id should start with a letter and only contain '
                        . 'letters, numbers, underscores ("_"), hyphens ("-") and colons (":").',
                        $id
                    )
                );
            }
        }
    }
protected function validateId($id, $fullCheck = false)
    {
        if (!$id) {
            throw new Exception\InvalidArgumentException('The item id must not be empty.');
        }
        if ($fullCheck) {
            if (!is_string($id)) {
                throw new Exception\UnexpectedTypeException($id, 'string', 'id');
            }
            if (!$this->isValidId($id)) {
                throw new Exception\InvalidArgumentException(
                    sprintf(
                        'The "%s" string cannot be used as the item id because it contains illegal characters. '
                        . 'The valid item id should start with a letter and only contain '
                        . 'letters, numbers, underscores ("_"), hyphens ("-") and colons (":").',
                        $id
                    )
                );
            }
        }
    }
protected function validateId ( $ id , $ fullCheck = false ) { if ( ! $ id ) { throw new Exception \ InvalidArgumentException ( 'The item id must not be empty.' ) ; } if ( $ fullCheck ) { if ( ! is_string ( $ id ) ) { throw new Exception \ UnexpectedTypeException ( $ id , 'string' , 'id' ) ; } if ( ! $ this -> isValidId ( $ id ) ) { throw new Exception \ InvalidArgumentException ( sprintf ( 'The "%s" string cannot be used as the item id because it contains illegal characters. ' . 'The valid item id should start with a letter and only contain ' . 'letters, numbers, underscores ("_"), hyphens ("-") and colons (":").' , $ id ) ) ; } } }
Checks if the given value can be used as the layout item id

@param string $id        The layout item id
@param bool   $fullCheck Determines whether all validation rules should be applied
or it is required to validate for empty value only

@throws Exception\InvalidArgumentException if the id is not valid
Checks if the given value can be used as the layout item id