NAME

XML::Catalogs - Basic framework to provide DTD catalogs

VERSION

Version 1.0.1

SYNOPSIS

    To make a catalog:

        Use XML::Catalogs::HTML as an example

    To use a catalog:

        use XML::Catalogs::FOO -libxml;

            ---

        use XML::Catalogs::FOO;

        XML::Catalogs->notify_libxml();

            ---

        use XML::Catalogs::FOO;

        my $url  = XML::Catalogs::FOO->get_catalog_url();
        my $path = XML::Catalogs::FOO->get_catalog_path();

DESCRIPTION

To properly parse named entities in an XML document, the parser must have access to the XML subformat's DTDs.

XML::LibXML, for one, does not cache DTDs it downloads. Instead, it relies on them being in the system's XML catalog. This is not always configured properly for a number of reasons.

An XML catalog is simply a set of DTDs and a table of contents that associates DTD identifiers with the DTDs.

This module provides a simple framework to package XML catalogs. It also provides a simple method to notify XML::LibXML of DTDs that may not be present in the system's catalog.

It works on all platforms, it works without requiring root priviledges, and it works with CPAN's dependency system.

CLASS METHODS

use XML::Catalogs::FOO -libxml

This loads XML::Catalogs::FOO and calls XML::Catalogs::FOO->notify_libxml()

$subclass->notify_libxml()

This method informs XML::LibXML of the subclass's catalog. XML::LibXML will use the local DTDs referenced by the catalog instead of downloading them. This only affects the current process.

This mechanism does not stop working when XML::LibXML's ->no_network(1) option is used. When using that option, XML::LibXML refrains from downloading remote resources.

$subclass->get_catalog_url()

Returns a file:// URL to the subclass's catalog.

$subclass->get_catalog_path()

Returns the file path of the subclass's catalog.

SEE ALSO

• http://en.wikipedia.org/wiki/XML_Catalog, Wikipedia's entry on XML Catalogs.

• XML::LibXML, an excellent XML parser that supports catalogs.

• XML::Catalogs::HTML, a module using this framework.

• http://www.w3.org/blog/systeam/2008/02/08/w3c_s_excessive_dtd_traffic, An example of the real world effects of not having local DTDs.

BUGS

Please report any bugs or feature requests to bug-XML-Catalogs at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=XML-Catalogs. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc XML::Catalogs

You can also look for information at:

• Search CPAN

  http://search.cpan.org/dist/XML-Catalogs

• RT: CPAN's request tracker

  http://rt.cpan.org/NoAuth/Bugs.html?Dist=XML-Catalogs

• AnnoCPAN: Annotated CPAN documentation

  http://annocpan.org/dist/XML-Catalogs

• CPAN Ratings

  http://cpanratings.perl.org/d/XML-Catalogs

AUTHOR

Eric Brine, <ikegami@adaelis.com>

COPYRIGHT & LICENSE

Public domain. No rights reserved.