Use XSLT to generate RSS item description

RSS specifications do not allow HTML markup in title or description elements. If you want to include HTML markup in RSS elements, it has to be quoted, for example <b>bold</b>. Doing this in any server-side scripting language is easy, for example, ASP provides Server.HTMLEncode function. If you use XSLT to transform internal XML documents into RSS feeds, the task gets trickier, as XSLT provides no equivalent function.

The following XSLT templates solve the problem: call the outputQuotedTree template in the context of input node containing HTML markup and it will generate quoted contents of its child nodes.

<xsl:template name="outputQuotedTree">
  <xsl:for-each select="node() ¦ text()">
    <xsl:call-template name="outputTextNode" />
  </xsl:for-each>
</xsl:template>

 
<xsl:template name="outputTextNode">
  <xsl:choose>
    <xsl:when test="name() = ''">
      <xsl:value-of select="." />
    </xsl:when>
    <xsl:otherwise>
      <!-- Emit the opening tag -->
      <xsl:text>&lt;</xsl:text><xsl:value-of select="name()" />
      <!-- Emit the attributes of the opening tag -->
      <xsl:for-each select="@*">
        <xsl:text> </xsl:text>
        <xsl:value-of select="name()"/><xsl:text>='</xsl:text>
        <xsl:value-of select="."/>
        <xsl:text>'</xsl:text>
      </xsl:for-each>
      <xsl:choose>
        <xsl:when test="node() ¦ text()">
          <!-- If there are children, close the start tag and 
           process the children -->
          <xsl:text>&gt;</xsl:text>
          <xsl:for-each select="node() ¦ text()">
            <xsl:call-template name="outputTextNode" />
          </xsl:for-each>
          <!-- Emit the closing tag -->
          <xsl:text>&lt;/</xsl:text>
          <xsl:value-of select="name()" />
          <xsl:text>&gt;</xsl:text>
        </xsl:when>
        <xsl:otherwise>
          <!-- No children, emit the self-closing tag -->
          <xsl:text>/&gt;</xsl:text>
        </xsl:otherwise>
      </xsl:choose> 
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

 
</xsl:stylesheet>