Content Syndication with RSS

Name

mod_syndication

Synopsis

mod_syndication gives aggregators and feed users an idea of how often the feed changes. By giving this information, you prevent everyone from wasting time and bandwidth by asking for your feed too often or, indeed, too seldom. It is the third module to achieve Standard status.

mod_syndication supersedes the skipHours and skipDays elements of mod_rss091. Clients usually prefer the mod_syndication values over mod_rss091.

Namespace

mod_syndication takes sy: as its prefix and http://purl.org/rss/1.0/modules/syndication as its identifying URI. Thus:

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
         xmlns="http://purl.org/rss/1.0/"
         xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
>

Elements

The mod_syndication elements are all subelements of channel :

sy:updatePeriod

Takes a value of hourly, daily, weekly, monthly, or yearly.

sy:updateFrequency

A number representing the number of times the feed should be refreshed during the updatePeriod. For example, an updatePeriod of hourly and an updateFrequency of 2 will make the aggregator refresh the feed twice an hour. If this element is missing, the default is 1.

sy:updateBase

The date and time, in W3CDTF format, from which all calculations should originate.

Example

Example 7-19. A part of a channel containing the mod_syndication elements

<channel rdf:about="http://meerkat.oreillynet.com/?_fl=rss1.0"> <title>Meerkat</title> <link>http://meerkat.oreillynet.com</link> <description>Meerkat: ...