NAME
SeeAlso::Identifier::ISBN - international standard book number identifier
METHODS
new ( [ $value ] )
Create a new ISBN identifier.
value ( [ $value ] )
Get and/or set the value of this identifier. Returns undef or the valid value ISBN-13 with hyphens.
indexed
Return undef or the valid ISBN-13 without hyphens.
uri
Returns a Uniform Resource Identifier (URI) for this ISBN if possible.
Unfortunately RFC 3187 broken, because it does not oblige normalization. But this method does: first only valid ISBN (with valid checkdigit) are allowed, second all ISBN are converted to ISBN-13 notation without hyphens. URIs without defined normalization and valitidy check are pointless.
Up to now the "urn:isbn"-flavor of URI for ISBN is used but you could also use "http://purl.org/isbn/" instead.
normalized
Normalize to the URI.
valid
Returns whether the ISBN is valid.