Delphi and XML

As you can see, each tag describes its contents very clearly. For example, the <title> tag describes the title, the description tag shows the description, and so on. Below is an example of an XSL style sheet:

<?xml version="1.0" ?>

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

<xsl:output method="xml" encoding="iso-8859-1" omit-xml-declaration="yes" indent="yes"/>

<xsl:template match="*">

<table border="1" width="600" align="center">

<tr><td valign="top" align="center" class="title" bgcolor="silver" >

<a>

<xsl:attribute name="href">

<xsl:value-of select="*[local-name()='channel']/*[local-name()='link']"/>

</xsl:attribute>

<xsl:attribute name="target">

<xsl:text>top</xsl:text>

</xsl:attribute>

<xsl:value-of select="*[local-name()='channel']/*[local-name()='title']" disable-output-escaping="yes"/>

</a>

<xsl:text disable-output-escaping="yes">&amp;nbsp;</xsl:text>

<xsl:value-of select="*[local-name()='channel']/*[local-name()='lastBuildDate']"/>

</td></tr><tr><td valign="top" bgcolor="ghostwhite" class="headlines" >

<ul>

<xsl:for-each select="//*[local-name()='item']">

<li>

<a>

<xsl:attribute name="href">

<xsl:value-of select="*[local-name()='link']"/>

</xsl:attribute>

<xsl:attribute name="target">

<xsl:text>top</xsl:text>

</xsl:attribute>

<xsl:value-of select="*[local-name()='title']" disable-output-escaping="yes"/>

</a>

<xsl:text disable-output-escaping="yes">&amp;nbsp;</xsl:text>

<xsl:value-of select="*[local-name()='description']" disable-output-escaping="yes"/>

</li>

</xsl:for-each>

</ul>

</td></tr>

</table>

</xsl:template>

<xsl:template match="/">

<xsl:apply-templates/>

</xsl:template>

</xsl:stylesheet>

XML has a few disadvantages as well. The biggest disadvantage is that, without a formal description, a document is worth little. If you want to exchange documents with another company, for example, you will have to agree on every single point, starting from what each tag means; you will also have to agree on the semantic meaning of the content.

Another disadvantage is that XML documents are a great deal larger than most text files. On top of that, the repeated opening and closing tags use a lot of space. On the other hand. XML compresses well.

Now you have some idea of what the Extensible Markup Language is all about. Let’s take a look at the syntax.