NAME

       XML::Catalog - Resolve public identifiers and remap system identifiers

SYNOPSIS

         use XML::Catalog;
         my $catalog=XML::Catalog->new('/xml/catalog.cat');
         $catalog->add('http://www.w3.org/xcatalog/mastercat.xml');
         my $sysid=$catalog->resolve_public('-//John Cowan//LOC Diacritics');
         my $newsysid=$catalog->remap_system('http://www.w3.org');
         $parser->setHandlers(ExternEnt=>$catalog->get_handler($parser));

   Oasis Example
         $ perl -e 'use XML::Catalog; \
         $pubid = q|-//OASIS//DTD DocBook XML V4.5//EN|; \
         my $catalog=XML::Catalog->new("/etc/xml/catalog"); \
         print $catalog->resolve_public($pubid), "\n";'

         file:///usr/share/sgml/docbook/xml-dtd-4.5-1.0-51.el6/docbookx.dtd

DESCRIPTION

       This module implements draft 0.4 of John Cowan's XML Catalog (formerly known as XCatalog)
       proposal (<http://www.ccil.org/~cowan/XML/XCatalog.html>).  Catalogs may be written in
       either SOCAT or XML syntax (see the proposal for syntax details); XML::Catalog will assume
       SOCAT syntax if the catalog is not in well-formed XML syntax.

       This module, as of 1.0.0, also supports Oasis XML catalogs.

CONSTRUCTOR

       new(URL [,URL]*)
           Read the catalog identified by URL and return a catalog object implementing it.  If
           more than one URL is given, chain the additional catalogs as extensions to the catalog
           (they will be searched before catalogs specified by EXTEND entries).

           All URLs must be absolute.  A URL with no protocol is treated as a filename.

METHODS

       add(URL [,URL]*)
           Chain the catalogs identified by the URL(s) to the current catalog.

       resolve_public(PUBID)
           Translate the public identifier PUBID to a system identifier.  Returns undef if the
           identifier could not be translated.

       remap_system(SYSID)
           Remap the system identifier SYSID as specified by the catalog.  Returns SYSID
           unchanged if no remapping was found.

       get_handler(PARSER)
           Returns a coderef to a resolver suitable for use as the ExternEnt handler for an
           XML::Parser object.  The resolver will first attempt to resolve a public identifier if
           supplied, and then attempt to remap the resulting system identifier (or the original
           system identifier if no public identifier was supplied).  It will then call the
           original ExternEnt handler associated with the parser object.  PARSER is the parser
           object; it is needed as an argument in order to obtain the original handler.

       add_delegate($pubid,  $href)
           TBD

       add_extend($href)
           TBD

       add_extend_object($cat, $group )
           TBD

       add_map($pubid,  $href)
           TBD

       add_remap($sysid,  $href)
           TBD

       build($url)
           create new catalog object

       fix_base($url)
           TBD

       parse
           TBD

       parse_SOCAT($ct)
           TBD

       parse_XML($ct)
           TBD

       set_base($href)
           TBD

BUGS / TODO

       Searching of chained catalogs is not purely depth-first (EXTEND items in a chained catalog
       will be searched before EXTEND items in the original catalog.

       Error checking leaves much to be desired.

AUTHOR

       Current Author:

               Jeff Fearn E<lt>jfearn@cpan.orgE<gt>.

       Former Authors:

               Eric Bohlman E<lt>ebohlman@netcom.comE<gt>.

COPYRIGHT

       Copyright (c) 1999-2000 Eric Bohlman.  All rights reserved.  Copyright (c) 2013 Jeff
       Fearn. All rights reserved.

       This program is free software; you can use/modify/redistribute it under the same terms as
       Perl itself.