MagpieRSS: RSS for PHP

News!

• Excited to announce that AOE media, a TYPO3 & Open Source provider from Germany has recently agreed to provide continues sponsoring for MagpieRSS.
• Magpie links page has been rebuilt, and is now driven by del.icio.us
• The Magpie Blog has been revived and is the place for Magpie news and howtos.
• Atom support is no longer alpha
  • Download MagpieRSS 0.61
• Magpie 0.6a (alpha) now available
  • Adds experimental parsing support for Atom
• Two new sources of MagpieRSS information:
  • MagpieRSS links is a partial list of all the cool stuff people have done with Magpie.
• MagpieRSS 0.52 Now Compatible with PHP 4.3.2
  • Improved socket handling in HTTP library
  • Thanks go to Scott, and Phil for bug reports, and especially to Steve for amazing debugging work.
• MagpieRSS 0.51 Released
  • important bugfix, please upgrade
  • fixes silent failure when PHP is built without zlib support
• Feed On Feeds Uses Magpie
  • server based PHP RSS aggregator built with MagpieRSS
  • easy to install, easy to use.
• MagpieRSS 0.5 Released
  • supports transparent HTTP gzip content negotiation for reduced bandwidth usage
  • quashed some undefined index notices

Why?

I wrote MagpieRSS out of a frustration with the limitations of existing solutions. In particular many of the existing PHP solutions seemed to:
• use a parser based on regular expressions, making for an inherently fragile solution
• only support early versions of RSS
• discard all the interesting information besides item title, description, and link.
• not build proper separation between parsing the RSS and displaying it.
In particular I failed to find any PHP RSS parsers that could sufficiently parse RSS 1.0 feeds, to be useful on the RSS based event feeds we generate at Protest.net.

Features

• Easy to Use

  As simple as:

  	require('rss_fetch.inc');
  	$rss = fetch_rss($url);
  	

• Parses RSS 0.9 - RSS 1.0

  Parses most RSS formats, including support for 1.0 modules and limited namespace support. RSS is packed into convenient data structures; easy to use in PHP, and appropriate for passing to a templating system, like Smarty.

• Integrated Object Cache

  Caching the parsed RSS means that the 2nd request is fast, and that including the rss_fetch call in your PHP page won't destroy your performance, and force you to reply on an external cron job. And it happens transparently.

• HTTP Conditional GETs

  Save bandwidth and speed up download times with intelligent use of Last-Modified and ETag.
  See HTTP Conditional Get for RSS Hackers

• Configurable

  Makes extensive use of constants to allow overriding default behaviour, and installation on shared hosts.

• Modular

  • rss_fetch.inc - wraps a simple interface (fetch_rss()) around the library.
  • rss_parse.inc - provides the RSS parser, and the RSS object
  • rss_cache.inc - a simple (no GC) object cache, optimized for RSS objects
  • rss_utils.inc - utility functions for working with RSS. currently provides parse_w3cdtf(), for parsing W3CDTF into epoch seconds.

• More

  • Secure - supports HTTP authentication, and SSL
  • Bandwidth friendly - supports transparent GZIP encoding to reduce bandwidth usage
  • Does not use fopen(), work even if allow_url_fopen is disabled.

Magpie's approach to parsing RSS

Magpie takes a naive, and inclusive approach. Absolutely non-validating, as long as the RSS feed is well formed, Magpie will cheerfully parse new, and never before seen tags in your RSS feeds.

This makes it very simple support the varied versions of RSS simply, but forces the consumer of a RSS feed to be cognizant of how it is structured.(at least if you want to do something fancy)

Magpie parses a RSS feed into a simple object, with 4 fields: channel, items, image, and textinput.

channel

$rss->channel contains key-value pairs of all tags, without nested tags, found between the root tag (<rdf:RDF>, or <rss>) and the end of the document.

items

$rss->items is an array of associative arrays, each one describing a single item. An example that looks like:

<item rdf:about="http://protest.net/NorthEast/calendrome.cgi?span=event&ID=210257">
<title>Weekly Peace Vigil</title>
<link>http://protest.net/NorthEast/calendrome.cgi?span=event&ID=210257</link>
<description>Wear a white ribbon</description>
<dc:subject>Peace</dc:subject>
<ev:startdate>2002-06-01T11:00:00</ev:startdate>
<ev:location>Northampton, MA</ev:location>
<ev:enddate>2002-06-01T12:00:00</ev:enddate>
<ev:type>Protest</ev:type>
</item>

Is parsed, and pushed on the $rss->items array as:

array(
	title => 'Weekly Peace Vigil',
	link => 'http://protest.net/NorthEast/calendrome.cgi?span=event&ID=210257',
	description => 'Wear a white ribbon',
	dc => array (
			subject => 'Peace'
		),
	ev => array (
		startdate => '2002-06-01T11:00:00',
		enddate => '2002-06-01T12:00:00',
		type => 'Protest',
		location => 'Northampton, MA'
	)
);

image and textinput

$rss->image and $rss-textinput are associative arrays including name-value pairs for anything found between the respective parent tags.

Usage Examples:

A very simple example would be:

require_once 'rss_fetch.inc';

$url = 'http://magpie.sf.net/samples/imc.1-0.rdf';
$rss = fetch_rss($url);

echo "Site: ", $rss->channel['title'], "<br>
";
foreach ($rss->items as $item ) {
	$title = $item[title];
	$url   = $item[link];
	echo "<a href=$url>$title</a></li><br>
";
}

More soon....in the meantime you can check out a cool tool built with MagpieRSS, version 0.1.

Todos

RSS Parser

• Swap in a smarter parser that includes optional support for validation, and required fields.
• Improve RSS 2.0 support, in all its wacky permutations (as much as I'm annoyed by it)
• Improve support for modules that rely on attributes

RSS Cache

• Light-weight garbage collection

Fetch RSS

• Attempt to auto-detect an RSS feed, given a URL following, much like rssfinder.pydoes.

Misc

• More examples
• A test suite
• RSS generation, perhaps with RSSwriter?

Getting Help With Magpie

• Read the Frequently Asked Questions
• Read How to Get Help with MagpieRSS
• Read over the How To section on the links page, to see if an existing solutions work for you.
• Read over the mailing list archives
• Subscribe to magpierss-general and ask your question.

RSS Resources

• RSS Tutorial for Content Publishers and Webmasters is a great place to start.
• RSS Workshop: Publish and Syndicate Your News to the Web is also a good introduction
• Finding More Channels on how to find RSS feeds.
• The Mapgie FAQ and Links pages can be very useful.
• RSS-DEV mailing list is generally a very helpful, informative space, with the occasional heated debate
• RSS Validator

License and Contact Info

Magpie is distributed under the GPL license...

Questions, and suggestions, magpierss-general@lists.sf.net

coded by: kellan (at) protest.net, feedback is always appreciated.

Development sponsored in part by AOE media, a TYPO3 & Open Source provider from Germany.