NAME

SeeAlso::Identifier::GND - Identifier of the GND Authority File

DESCRIPTION

This class handles an identifier of the "Gemeinsame Normdatei" (GND), a common authority file of names, subjects, and organizations that is coordinated by the German National Library. GND is beeing build by combining the Names Authority File "Personennamendatei" (PND), the Subject Headings Authority File "Schlagwortnormdatei" (SWD), and the Corporate Body Authority File "Gemeinsame Körperschaftsdatei" (GKD). Furthermore it is planned to include the Uniform Title Authority file "Einheitssachtitel" (EST).

Each authority file record has an unique number which is modeled by this class. A GND number consists of up to eight digits and a check digit which may also be an 'X'. Heading zero digits are removed. There is an URI representation of a GND number that can be created by prepending 'http://d-nb.info/gnd/'.

This subclass of SeeAlso::Identifier overrides the constructor new and the methods valid and normalized.

METHODS

new ( [ $value ] )

Create a new GND identifier.

value ( [ $value ] )

Get and/or set the value of this identifier. Whitespaces at the ends of the value string, the character '-', and one of the prefixes 'GND', 'PND', 'GKD', 'EST', 'http://d-nb.info/gnd/' are removed as well as zeros at the beginning.

valid ( )

Test whether the GND consists of 8 digits plus the right check digit. Because there are two methods for check digit computation, not all errors can be detected.

normalized ( )

Return a normalized version of the GND identifier as Uniform Resource Identifier (URI) by adding the prefix 'http://d-nb.info/gnd/'. If the identifier is not valid, this methods returns an empty string.

indexed ( )

Return a shortened version of the GND identifier, that is the valid GND without hyphen, prefix, or heading zeroes. You could further strip off the check digit.

AUTHOR

Jakob Voss <jakob.voss@gbv.de>

LICENSE

Copyright (C) 2007-2009 by Verbundzentrale Goettingen (VZG) and Jakob Voss

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.