Difference between revisions of "Atom"

Atom is a syndication (feed) format, defined by the IETF in RFC 4287. RDF-4946 defines an extension to Atom 1.0 for specifying license information.

Example Uses

• Feed: http://ccmixter.org/media/feed/atom/audio
• Consumer: ccHost via Sample Pool API

Specifying a License

Licenses are specified using the link element with rel="license".

License information may be provided at either the feed or the entry level; in the case that both exist, the entry license overrides the feed. Note that more than one license may be specified at either level, denoting a multiple license offering.

    <feed xmlns="http://www.w3.org/2005/Atom">
      <id>http://www.example.com/myfeed</id>
      <title>My Example Feed</title>
      <updated>2005-07-28T12:00:00Z</updated>
      <link href="http://www.example.com/myfeed" />
      <link rel="license" type="application/rdf+xml"
        href="http://creativecommons.org/licenses/by-nc/2.5/rdf" />
      <author><name>James</name></author>
      <entry>
        <id>tag:entries.org,2005:1</id>
        <title>Atom Powered Robots Run Amok</title>
        <updated>2005-06-28T12:00:00Z</updated>
        <link href="http://www.example.org/entries/1" />
        <summary>Atom Powered Robots Run Amok</summary>
        <author><name>Jane Smith</name></author>
        <link rel="license" type="text/html"
          href="http://creativecommons.org/licenses/by/2.5/" />
      </entry>
    </feed>

In the example above the entire feed is licensed under Attribute-Non Commercial 2.5, with the one entry licensed under Attribution 2.5.

Additional Metadata

Note that this is a draft we are currently working on; this notice will be removed after collecting feedback.

A web statement provides additional confidence regarding metadata assertions. morePermissions allows content creators to provide a link to a URL where additional permissions, beyond those provided by the license, may be secured.

Atom provides support for extending the feed using fully qualified URIs for the rel attribute on link tags. The web statement and more permissions information may be supplied one of two ways: as a link or as RDFa in the content of an entry.

Using links

       <entry>
         <id>tag:entries.org,2005:1</id>
         <title>Atom Powered Robots Run Amok</title>
         <updated>2005-06-28T12:00:00Z</updated>
         <link href="http://www.example.org/entries/1" />
         <summary>Atom Powered Robots Run Amok</summary>
         <author><name>Jane Smith</name></author>
         <link rel="license" type="text/html"
           href="http://creativecommons.org/licenses/by/2.5/" />

         <link rel="http://ns.adobe.com/xap/1.0/rights/WebStatement"
           type="text/html" href="http://example.org/more_info" />
         <link rel="http://creativecommons.org/ns#morePermissions"
           type="text/html" href="http://example.org/pay_me" />

       </entry>

Using RDFa

       <entry>
         <id>tag:entries.org,2005:1</id>
         <title>Atom Powered Robots Run Amok</title>
         <updated>2005-06-28T12:00:00Z</updated>
         <link href="http://www.example.org/entries/1" />
         <summary>Atom Powered Robots Run Amok</summary>
         <author><name>Jane Smith</name></author>
         <link rel="license" type="text/html"
           href="http://creativecommons.org/licenses/by/2.5/" />

         <link rel="http://ns.adobe.com/xap/1.0/rights/WebStatement"
           type="text/html" href="http://example.org/more_info" />
         <link rel="http://creativecommons.org/ns#morePermissions"
           type="text/html" href="http://example.org/pay_me" />

         <content type="xhtml" xml:lang="en">
           <div xmlns="http://www.w3.org/1999/xhtml" 
                xmlns:cc="http://creativecommons.org/ns#"
                xmlns:xapRights="http://ns.adobe.com/xap/1.0/rights/">
             <p>Lorem, ipsum; 
                <a href="http://example.org/more_info" rel="xapRights:WebStatement">more metadata</a>
                <a href="http://example.org/pay_me" rel="cc:morePermissions">additional rights</a>
             </p>
          </div>
       </content>

       </entry>

Use with Podcasts

Using RDFa you can also provide additional metadata about linked content. This is useful when deploying a podcast; your XHTML can provide rich metadata which allows clients to increase confidence in the metadata.