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Business-ISBN-1.0
River stage two • 11 direct dependents • 14 total dependents
6 ++
/ Business::ISBN

NAME

Business::ISBN - work with International Standard Book Numbers

SYNOPSIS

        use Business::ISBN;
        
        $isbn_object = new Business::ISBN('1565922573');
        $isbn_object = new Business::ISBN('1-56592-257-3');
                
        #print the ISBN with hyphens at positions specified
        #by constructor
        print $isbn_object->as_string;
        
        #print the ISBN with hyphens at specified positions.
        #this not does affect the default positions
        print $isbn_object->as_string([]);
        
        #print the country code, country, or publisher code
        print $isbn->country_code;
        print $isbn->country;
        print $isbn->publisher_code;
        
        #check to see if the ISBN is valid
        $isbn_object->is_valid;
        
        #fix the ISBN checksum.  BEWARE:  the error might not be
        #in the checksum!
        $isbn_object->fix_checksum;

DESCRIPTION

new($isbn)

The constructor accepts a scalar representing the ISBN.

The string representing the ISBN may contain characters other than [0-9xX], although these will be removed in the internal representation. The resulting string must look like an ISBN - the first nine characters must be digits and the tenth character must be a digit, 'x', or 'X'.

The constructor attempts to determine the country code and the publisher code based on data from . If these data cannot be determined, the constructor returns an error number:

        -3 Could not determine publisher code
        -2 Could not determine country code
        -1 ISBN is not valid

The string passed as the ISBN need not be a valid ISBN as long as it superficially looks like one. This allows one to use the fix_checksum() method. Despite the disclaimer in the discussion of that method, the author has found it extremely useful. One should check the validity of the ISBN with is_valid() rather than relying on the return value of the constructor.

If the constructor decides it can't create an object, it returns undef. It may do this if the string passed as the ISBN can't be munged to the internal format.

$obj->publisher_code

Returns the publisher code.

$obj->country_code

Returns the country code.

$obj->country

Returns the country designation associated with the country code.

$obj->hyphen_positions

Returns the list of hyphen positions as determined from the country and publisher codes. the as_string method provides a way to temporarily override these positions and to even forego them altogether.

$obj->as_string(), $obj->as_string([])

Return the ISBN as a string. This function takes an optional anonymous array (or array reference) that specifies the placement of hyphens in the string. An empty list produces a string with no hyphens.

The positions specified in the passed anonymous array are only used for one method use and do not replace the values specified by the constructor.

Positions less than 1 and greater than 9 are silently ignored.

A terminating 'x' is changed to 'X'.

$obj->is_valid()

Returns 1 if the checksum is valid and the country and publisher codes are defined.

Returns -1 if the ISBN does not pass the checksum test, and 1 if it does. The constructor accepts invalid ISBN's so that they might be fixed with fix_checksum.

Returns -2 if a country code could not be determined (relies on a valid checksum).

Returns -3 if a publisher code could not be determined (relies on a valid checksum and country code).

$obj->fix_checksum()

Replace the tenth character with the checksum the corresponds to the previous nine digits. This does not guarantee that the ISBN corresponds to the product one thinks it does, or that the ISBN corresponds to any product at all. It only produces a string that passes the checksum routine. If the ISBN passed to the constructor was invalid, the error might have been in any of the other nine positions.

AUTHOR

brian d foy <comdog@computerdog.com>

please see <URL:http://computerdog.com/brian/style.html> for guidelines on proper attribution.

The coding of this module was supported by Smith Renaud, Inc. <URL:http://www.smithrenaud.com> and released under the terms of the Perl Artistic License.

Country code and publisher code graciously provided by Steve Fisher <stevef@teleord.co.uk> of Whitaker (the UK ISBN folks and the major bibliographic data provider in the UK). "Whitaker - helping to link authors to readers worldwide"

Thanks to Julie Koo of Kaya Publishing <URL:http://www.kaya.com> for useful discussions.