RSS enclosure
 newspapers · JSTOR (September 2017) |
RSS enclosures are a way of attaching multimedia content to RSS feeds with the purpose of allowing that content to be prefetched.[1] Enclosures provide the URL of a file associated with an entry, such as an MP3 file to a music recommendation or a photo to a diary entry. Unlike e-mail attachments, enclosures are merely hyperlinks to files. The actual file data is not embedded into the feed (unless a data URL is used). Support and implementation among aggregators varies: if the software understands the specified file format, it may automatically download and display the content, otherwise provide a link to it or silently ignore it.
The addition of enclosures to RSS, as first implemented by Dave Winer in late 2000 [update]. In podcasts and related technologies enclosures are not merely attachments to entries, but provide the main content of a feed.
Syntax
[edit]In RSS 2.0, the syntax for the <enclosure> tag, an optional child of the <item> element, is as follows:
<enclosure url="http://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>.[2]
Prefetching
[edit]The RSS <enclosure> has similarities to:
- the SMIL <prefetch> element,
- the HTML <link> element with rel="prefetch".[2]
- the HTTP Link header with rel="prefetch". (See RFC 2068 section 19.6.2.4.)
- the Atom <link> element with rel="enclosure"
See also
[edit]References
[edit]- ^ "RSS Enclosures Use Case". Rssboard.org. Retrieved 3 October 2023.
- ^ "RSS Best Practices Profile". Rssboard.org. Retrieved 1 October 2017.
External links
[edit]- The <enclosure> tag in the RSS 2.0 specification
- mod_enclosure - Enclosures in RSS 1.x
- Enclosure intended use case