3.4 RSS 1.0

XML technology. By adding RDF, namespaces, and modularization, RSS 1.0 both gives and takes away: what it loses in simplicity, it gains in extensibility and improved support for metadata. The Dublin Core metadata set is introduced at both the item level and the channel level. At the time of this writing there are over 14 additional sets of elements available as modules to the base specification, providing support for listing objects as diverse as streaming media and real-world events. Figure 3-4 shows a tree representation of RSS 1.0.

Figure 3-4. A tree representation of RSS 1.0

3.4.1 The Specification in Summary

• XML-based, but in a more complex form than in previous versions.

• RDF-based, providing much richer metadata.

• Modularized, providing massive extensibility but also additional complexity.

• Pull-based, but with features to allow Publish and Subscribe.

Example 3-4 is an example of RSS 1.0 using four optional modules.

Example 3-4. An example of RSS 1.0 using four optional modules

<?xml version="1.0" encoding="utf-8"?>
<rdf:RDF 
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
  xmlns:dc="http://purl.org/dc/elements/1.1/"
  xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
  xmlns:co="http://purl.org/rss/1.0/modules/company/"
  xmlns:ti="http://purl.org/rss/1.0/modules/textinput/"
  xmlns="http://purl.org/rss/1.0/"
>   
   
<channel rdf:about="http://meerkat.oreillynet.com/?_fl=rss1.0">
  <title>Meerkat</title>
  <link>http://meerkat.oreillynet.com</link>
  <description>Meerkat: An Open Wire Service</description>
  <dc:publisher>The O'Reilly Network</dc:publisher>
  <dc:creator>Rael Dornfest (mailto:[email protected])</dc:creator>
  <dc:rights>Copyright &#169; 2000 O'Reilly &amp; Associates, Inc.</dc:rights>
  <dc:date>2000-01-01T12:00+00:00</dc:date>
  <sy:updatePeriod>hourly</sy:updatePeriod>
  <sy:updateFrequency>2</sy:updateFrequency>
  <sy:updateBase>2000-01-01T12:00+00:00</sy:updateBase>
   
  <image rdf:resource="http://meerkat.oreillynet.com/icons/meerkat-powered.jpg" />
  <textinput rdf:resource="http://meerkat.oreillynet.com" />
   
  <items>
    <rdf:Seq>
      <rdf:li resource="http://c.moreover.com/click/here.pl?r123" />
    </rdf:Seq>
  </items>
</channel>
   
<image rdf:about="http://meerkat.oreillynet.com/icons/meerkat-powered.jpg">
  <title>Meerkat Powered!</title>
  <url>http://meerkat.oreillynet.com/icons/meerkat-powered.jpg</url>
  <link>http://meerkat.oreillynet.com</link>
</image>
   
<textinput rdf:about="http://meerkat.oreillynet.com">
  <title>Search Meerkat</title>
  <description>Search Meerkat's RSS Database...</description>
  <name>s</name>
  <link>http://meerkat.oreillynet.com/</link>
  <ti:function>search</ti:function>
  <ti:inputType>regex</ti:inputType>
</textinput>
   
<item rdf:about="http://c.moreover.com/click/here.pl?r123">
  <title>XML: A Disruptive Technology</title>
  <link>http://c.moreover.com/click/here.pl?r123</link>
  <dc:description>This the description of the article</dc:description>
  <dc:publisher>The O'Reilly Network</dc:publisher>
  <dc:creator>Simon St.Laurent (mailto:[email protected])</dc:creator>
  <dc:rights>Copyright &#169; 2000 O'Reilly &amp; Associates, Inc.</dc:rights>
  <dc:subject>XML</dc:subject>
  <co:name>XML.com</co:name>
  <co:market>NASDAQ</co:market>
  <co:symbol>XML</co:symbol>
</item>
</rdf:RDF>