Create an RSS 0.91 document using a template, and gain a little essential background in RSS history.
RSS 0.91 is probably the most popular RSS format because it is the oldest and is so simple, which, as with so many other technologies, encourages adoption by the teeming masses. Here is a minimal 0.91 document, containing all the required elements and a few optional ones (it is named news.xml in the file archive):
<rss version="0.91"> <channel> <title>Wy'east Communications</title> <link>http://www.wyeast.net</link> <description> Wy'east Communications is an XML consultancy.</description> <language>en-us</language> <image> <url>http://www.wyeast.net/images/mthood.jpg</url> <title>Wy'east</title> <link>http://www.wyeast.net</link> </image> <item> <title>Legend of Wy'east</title> <link>http://www.wyeast.net/wyeast.html</link> <description>The Native American story behind the name Wy'east.</description> </item> </channel> </rss>
RSS 0.91 doesn’t
declare a namespace for its elements. The rss
element is the document element. It has a required attribute,
version
, whose value is 0.91
.
This element must have exactly one channel
child
and one or more item
children. Following the
channel
element are these elements:
title
A descriptive title for this channel. This should usually be the same as the content of the HTML element title on your main site page (such as index.html). The maximum number of characters allowed here is 100.
link
A URI for the channel. This should be a link to the web site that originates the feed—in this case, http://www.wyeast.net. Maximum length of this element is 500 characters.
description
A description of the channel, usually answering the question “What’s this site all about?” Limited to 500 characters.
For a comparison of the required and optional child elements of
channel
for both RSS 0.91 and 2.0, see Table 6-2 in
[Hack #83]
.
The image
is an optional element that has three
required child elements: url
, which contains a URL
for a JPG, GIF, or PNG image representing the channel (500 character
limit); title
, which contains the
alt
attribute value from the
img
element in HTML used for the graphic whose
link is in url
(100 character limit); and
link
, a link to the web site represented by the
link in url
. The elements title
and link
should have the same content as the
elements with the same names that are children of
channel
(500 character limit).
RSS 0.91 requires the first non-whitespace characters of the content
in link
and url
elements to
begin with ftp://
or http://
.
Others are not permitted. This restriction is lifted by RSS 2.0
[Hack #83]
.
The optional children of image
are
description
, width
, and
height
. description
should
contain the same advisory text as might be found in the
title
attribute on the a
element that creates the link associated with the graphic;
width
and height
are the width
and height of the graphic. By default, the value of
width
is 88 with a max of 144; the default value
of height
is 31 with a max of 400.
This document has only one item
element, though it
is common to have several (you can only have up to 15 in RSS 0.91
according to http://blogs.law.harvard.edu/tech/rss#comments). A channel
element
may have one or more item
children, which can
contain: title
, the title of the article or story
(100 character limit); link
, the URL to the story
(500 character limit); and description
, which
holds a summary of the article or story (500 character limit).
You can find a DTD for RSS 0.91 at http://my.netscape.com/publish/formats/rss-0.91.dtd.
Other optional children of channel
are shown in
Table 6-1. For more information on these and other
RSS 0.91 elements, see http://backend.userland.com/rss091.
Table 6-1. Optional children of channel in RSS 0.91
Element |
Description |
---|---|
|
Copyright notice for the channel |
|
Documentation for the RSS format used by the channel |
|
Last time channel content changed, in RFC 822 format, |
|
Email address of managing editor for the channel |
|
Publication date of channel, in RFC 822 format, |
|
Platform for Internet Content Selection (PICS) rating (http://www.w3.org/PICS/) |
|
Days to skip reading channel |
|
Hours to skip reading channel |
|
A text input box for the channel, such as a search box (required
children include |
|
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