Itemref for <spine> element of OPF file.
%opts is an anonymous hash that might containe followig keys:
linear (0 or 1) idhref (string)
Encode object to XML form using XML::Writer instance
Get/set reference to an OPS Content Document included in the manifest.
Get/set linear property. If $linear is true - document is primary, otherwise - auxiliary (like appendix, notes, etc..)
Oleksandr Tymoshenko, <email@example.com>
Please report any bugs or feature requests to <firstname.lastname@example.org>
Copyright 2009, 2010 Oleksandr Tymoshenko.
This module is free software; you can redistribute it and/or modify it under the terms of the BSD license. See the LICENSE file included with this distribution.