Creating browser-friendly RSS feeds

Posted by Dmytro Shteflyuk on under Development

RSS-feeds become the most popular content format in the web todays. There are tons of RSS-readers, aggregators, desktop and online tools for viewing feeds in the world. But what about Web-browsers? Every day I make same mistake: I click “RSS-feed” link and my browser displays XML-source of the feed. Why I can’t examine feed directly in my browser?

In this article I’ll try to create feed which will be displayed pretty well both in browser and RSS-reader. I’ll use XSLT 1.0 technology to do it (because my Firefox does not support XSLT 1.1).

First we need RSS-feed. I’ve saved digg.com RSS-feed under “programming” category (you can look at this feed here). This feed contains some additional fields in the item section (see RSS 2.0 Specification), this will be useful to show how you can extend my sample.

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<item>
  <title>Transparent PNG Images in IE</title>
  <link>http://digg.com/programming/Transparent_PNG_Images_in_IE</link>
  <description>Fellow digg user patrickweber commented w/ this URL. A
    javascript fix that passes off a transparent PNG to DirectX to
    render so IE can render PNG's. You can also do it with CSS via:
    filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true,
    sizingMethod=image src='
imgurlhere');</description>
  <pubDate>Wed, 5 Apr 2006 02:26:44 GMT</pubDate>
  <guid isPermaLink="true">http://digg.com/programming/Transparent_PNG_Images_in_IE</guid>
  <digg:diggCount>650</digg:diggCount>
  <digg:submitter>
    <digg:username>kefs</digg:username>
    <digg:userimage>/userimages/kefs/medium.jpg</digg:userimage>
  </digg:submitter>
  <digg:submitter>kefs</digg:submitter>
  <digg:category>programming</digg:category>
  <digg:commentCount>90</digg:commentCount>
</item>

HTML presentation for RSS-feed must contain buttons for add this feed to different online-readers. Brief instructions about using feed necessary too. I like CSS-based design therefor page layout will be placed in external CSS style sheet.

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<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="html"/>

  <xsl:template match="/">
    <html>
      <head>
        <title><xsl:value-of select="/rss/channel/title"/></title>
        <link rel="stylesheet" href="digg.css" type="text/css"/>
      </head>
      <xsl:apply-templates select="rss/channel"/>
    </html>
  </xsl:template>

  <xsl:template match="channel">
    <body>
      <div class="topbox">
        <p>This is a <strong>RSS-feed</strong> from the <xsl:value-of select="title"/>
          website. RSS feeds allow you to stay up to date with the latest news and
          features you want from  <xsl:value-of select="title"/>. To subscribe to it,
          you will need a News Reader or other similar device.</p>
      </div>
      <div class="contbox">
        <div class="header">
          <div class="fltl">
            <span class="subhead">Blog for: </span>
          </div>
          <a href="#" class="item">
            <img height="15" hspace="5" vspace="0" border="0" width="32" alt="RSS" src="rss_feed.gif" title="RSS " align="left"/>
            <xsl:value-of select="title"/>
          </a>
          <br class="fltclear"/>
        </div>
        <div class="mainbox">
          <div class="itembox">
            <ul>
              <xsl:apply-templates select="item"></xsl:apply-templates>
            </ul>
          </div>
          <div class="subscrbox">
            <div class="padrhsbox">
              <h2>Subscribe to this feed</h2>
              <p>You can subscribe to this RSS feed in a number of ways, including
                the following:</p>
              <ul>
                <li>Drag the orange RSS button into your News Reader</li>
                <li>Drag the URL of the RSS feed into your News Reader</li>
                <li>Cut and paste the URL of the RSS feed into your News Reader</li>
              </ul>
              <h3>One-click subscriptions</h3>
              <p>If you use one of the following web-based News Readers,
                click on the appropriate button to subscribe to the RSS feed.
              </p>
              <a href="#" onClick="window.location='http://add.my.yahoo.com/rss?url=' + window.location;return false;">
                <img height="17" width="91" vspace="3" border="0" alt="my yahoo" src="myyahoo.gif"/>
              </a><br/>
              <a href="#" onClick="window.location='http://www.bloglines.com/sub/'+ window.location;return false;">
                <img height="18" width="91" vspace="3" border="0" alt="bloglines" src="bloglines.gif"/>
              </a><br/>
              <a href="#" onClick="window.location='http://www.newsgator.com/ngs/subscriber/subext.aspx?url='+ window.location;return false;">
                <img height="17" width="91" vspace="3" border="0" alt="newsgator" src="newsgator.gif"/>
              </a><br/>
              <a href="#" onClick="window.location='http://client.pluck.com/pluckit/prompt.aspx?GCID=C12286x053&amp;a=' + window.location + '&amp;t={title}';return false;">
                <img src="pluspluck.png" vspace="3" border="0" alt="Subscribe with Pluck RSS reader"/>
              </a><br/>
              <a href="#" onClick="window.location='http://www.rojo.com/add-subscription?resource=' + window.location;return false;">
                <img src="add-to-rojo.gif" vspace="3" border="0" alt="Subscribe in Rojo"/>
              </a><br/>
              <a href="#" onClick="window.location='http://fusion.google.com/add?feedurl=' + window.location;return false;">
                <img src="add-to-google-plus.gif" vspace="3" border="0" width="104" height="17" alt="Add to Google"/>
              </a>
            </div>
          </div>
        </div>
      </div>
    </body>
  </xsl:template>

  <xsl:template match="item">
    <li>
      <a href="{link}">
        <xsl:value-of select="title"/>
      </a>
      <small> &#8212; <xsl:value-of select="pubDate"/></small>
      <br/>
      <div class="item_desc">
        <xsl:value-of select="description"/>
      </div>
    </li>
  </xsl:template>
</xsl:stylesheet>

It’s simple to integrate our XSLT-sheet with the RSS-feed. Just add following line after the <?xml ... ?> line:

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<?xml version="1.0"?>
<?xml-stylesheet title="XSL_formatting" type="text/xsl" href="digg.xsl"?>

In the beginning I made a promise to show how you can use custom digg fields. In the xsl:stylesheet we need to add digg namespace:

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<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:digg="http://digg.com//docs/diggrss/">

Please note that URL contains two slashes. Now we are ready to use custom digg attributes:

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  <xsl:template match="item">
    <li>
      <a href="{link}">
        <xsl:value-of select="title"/>
      </a>
      <small>
        by <strong><xsl:value-of select="digg:submitter/digg:username"/></strong>
        &#8212; <xsl:value-of select="pubDate"/>
        (<xsl:value-of select="digg:diggCount"/> diggs)
      </small>
      <br/>
      <div class="item_desc">
        <xsl:value-of select="description"/>
      </div>
    </li>
  </xsl:template>

You can look results here. Full sources are available for download.

Books recommended

7 Responses to this entry

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Splurov
said on April 6th, 2006 at 07:09 · Permalink

Осталось сделать расширение для FF, которое по-умолчанию применяет к rss-лентам xslt :)

said on April 6th, 2006 at 08:22 · Permalink

[…] In my previous post I’ve described how to display RSS-feed in browser using XSLT. But sometimes It’s necessary to change order of items in feed, for example sort them by date. XSLT 1.1 allows sorting by complex data types, but XSLT 1.0 does not and we need extract separate date parts. […]

said on April 25th, 2006 at 12:48 · Permalink

[…] Создание RSS-лент с возможностью просмотра из браузераВ этой заметке я попытаюсь создать ленту, которая будет нормально отображаться как в браузере, так и в RSS-клиенте. Я буду использовать технологию XSLT 1.0 (так как мой Firefox не поддерживает XSLT 1.1). […]

said on August 8th, 2006 at 13:33 · Permalink

This is amazing information. Do you know how to remove unwated tags in post data, and display everything else?
Like if there are object tags in post or javascript in post, I would like to ignore that.

said on August 8th, 2006 at 14:08 · Permalink

Yeah! It’s very common needed feature, therefor it’s implemented in standard PHP library.
Check the manual for strip_tags function.

said on September 8th, 2006 at 19:48 · Permalink

Is this only usable “server-side”? For example, I have a del.icio.us feed for a few bookmarks that I’d like to share between browsers. I’d like them sorted alphabetically, but I can’t seem to find a method of forcing Firefox to sort a feed how I want. The easy part is creating the transform, the hard part is forcing Firefox to use it. :) Any ideas?

said on September 8th, 2006 at 20:10 · Permalink

No, on client side you can do this too :-) Just in my xslt replace template match for / with following:

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  <xsl:template match="/">
    <xsl:variable name="doc" select="document('http://kpumuk.info/feed/')" />
    <html>
      <head>
        <title><xsl:value-of select="$doc/rss/channel/title"/></title>
        <link rel="stylesheet" href="digg.css" type="text/css"/>
      </head>
      <xsl:apply-templates select="$doc/rss/channel"/>
    </html>
  </xsl:template>

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