NAME
XML::RSS::LibXML - XML::RSS with XML::LibXML (parse-only)
SYNOPSIS
use XML::RSS::LibXML;
my $rss = XML::RSS::LibXML->new;
$rss->parsefile($file);
print "channel: $rss->{channel}->{title}\n";
foreach my $item (@{ $rss->{items} }) {
print " item: $item->{title} ($item->{link})\n";
}
# Add custom modules
$rss->add_module(uri => $uri, prefix => $prefix);DESCRIPTION
XML::RSS::LibXML uses XML::LibXML (libxml2) for parsing RSS instead of XML::RSS' XML::Parser (expat), while trying to keep interface compatibility with XML::RSS.
XML::RSS is an extremely handy tool, but it is unfortunately not exactly the most lean or efficient RSS parser, especially in a long-running process. So for a long time I had been using my own version of RSS parser to get the maximum speed and efficiency - this is the re-packaged version of that module, such that it adheres to the XML::RSS interface.
Use this module when you have severe performance requirements in parsing RSS files.
COMPATIBILITY
There seems to be a bit of confusion as to how compatible XML::RSS::LibXML is with XML::RSS: XML::RSS::LibXML is NOT 100% compatible with XML::RSS. For example, XML::RSS::LibXML is not capable of outputting RSS in various formats. It also doesn't do complete parsing of the XML document because of the way we deal with XPath and libxml's DOM (see CAVEATS below)
On top of that, I originally wrote XML::RSS::LibXML as sort of a fast replacement for XML::RAI, which looked cool in terms of abstracting the various modules. And therefore versions prior to 0.02 worked more like XML::RAI rather than XML::RSS. That was a mistake in hind sight, so it has been addressed.
From now on XML::RSS::LibXML will try to match XML::RSS's functionality as much as possible in terms of parsing RSS feeds. Please send in patches and any tests that may be useful!
PARSED FIELDS
METHODS
new
Creates a new instance of XML::RSS::LibXML
parse($string)
Parse a string containing RSS.
parsefile($filename)
Parse an RSS file specified by $filename
as_string()
Return the string representation of the parsed RSS.
add_module(uri => $uri, prefix => $prefix)
Adds a new module. You should do this before parsing the RSS. XML::RSS::LibXML understands a few modules by default:
rdf => "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
dc => "http://purl.org/dc/elements/1.1/",
sy => "http://purl.org/rss/1.0/modules/syndication/",
admin => "http://webns.net/mvcb/",
content => "http://purl.org/rss/1.0/modules/content/",
cc => "http://web.resource.org/cc/",
taxo => "http://purl.org/rss/1.0/modules/taxonomy/",So you do not need to add these explicitly.
PERFORMANCE
Here's a simple benchmark using benchmark.pl in this distribution:
daisuke@localhost XML-RSS-LibXML$ perl -Mlib=lib benchmark.pl index.rdf
Rate rss rss_libxml
rss 8.00/s -- -97%
rss_libxml 262/s 3172% --CAVEATS
No support whatsover for writing RSS. No plans to support it either.
Only first level data under <channel> and <item> tags are examined. So if you have complex data, this module will not pick it up. For most of the cases, this will suffice, though.
TODO
Tests. Currently tests are simply stolen from XML::RSS. It would be nice to have tests that do more extensive testing for correctness
SEE ALSO
XML::RSS, XML::LibXML, XML::LibXML::XPathContext
AUTHORS
Copyright 2005 Daisuke Maki <dmaki@cpan.org>, Tatsuhiko Miyagawa <miyagawa@bulknews.net>. All rights reserved.
Development partially funded by Brazil, Ltd. <http://b.razil.jp>