Subject: Advanced Internet Technology

Topic: RIA and Mashup

Difficulty: High

• Enclosure

  • Some weblogs and news feeds want to provide you with more than just ASCII text or HTML formatted articles. A weblog author might want to record his daily experiences and publish them as audio data (often MP3) and of course make this available in the weblog's feed too. This is done by adding enclosures to feed items. Adding an enclosure means adding an URL to an item which the feed reader application can download and play with an appropriate media player.

  • In RSS 2.0, the syntax for the <enclosure> tag, an optional child of the <item> element, is as follows:

    <enclosure url="https://example.com/file.mp3" length="123456789" type="audio/mpeg" />

    where the value of the url attribute is a URL of a file, length is its size in bytes, and type its mime type. It is recommended that only one <enclosure> element is included per <item>.

• Podcasting

  • Feeds with audio content are often called podcasts. The act of publishing such content is called podcasting. The Wikipedia page about podcasting is a good start to learn more about this publishing method.
  • Podcasting is the preparation and distribution of audio files using RSS to the computers of subscribed users.
  • These files may then be uploaded to digital music or multimedia players like the iPod.
  • A podcast can be easily created from a digital audio file. The podcaster first saves the file as an MP3 and then uploads it to the Web site of a service provider.
  • The MP3 file gets its own URL, which is inserted into an RSS XML document as an enclosure within an XML tag.