Dealing with Attributes and Elements in XPath with XSLT using ASP.NET 2.0
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This is the second article in a series focusing on XPath with XSLT using ASP.NET 2.0. The first article in this series focused on working elements. In this article, I will be focusing on working with attributes, attributes together with elements and searching for elements at various positions.
A
downloadable zip file is available for this article.
Even though this series is based on ASP.NET 2.0, I use it only as a transformation engine. The entire focus will be on working with XPath and XSLT. You can use any transformation engine according to your requirements, such as Java or others.
If you are new to a few of XSLT's concepts, I strongly suggest that you go through my first series, “Developing XSLT based Applications using ASP.NET 2.0.” It deals completely with XSLT. I will be using a few of the XSLT constructs in this series wherever appropriate. The entire setup for this article (along with ASP.NET 2.0 code and sample XML code) was listed in the first article of this series.
The entire solution (source code) for this article is available as a free download (in the form of a zip). All the applications in this series have been developed using Microsoft Visual Studio 2005 Professional Edition on Microsoft Windows Server 2003 Standard Edition together with Microsoft SQL Server 2005 Developer Edition as the database. You can even directly copy and paste the code given in this article and save it with the extensions XML or XSL to work with your own XSL parsers/engines.
I didn’t really test any of the code in any of the other tools/IDEs/servers/editions/versions. If you have any problems, please feel free to post in the discussion area.
Retrieving all values of a particular attribute at a particular hierarchy (or path)
In the previous article, we focused on working with only elements. Now it is time to work on attributes. Let us consider that I would like to list all the department names. All department names are available in the “Dname” attribute of the “Department” tag. The path of the “Department” tag is just below the root tag “EmployeeeDetails.”
The following is the first approach we can use to retrieve all values of a particular attribute at a particular location (using a separate template):
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<b>
<xsl:apply-templates select ="EmployeeDetails/Department"/>
</b>
</xsl:template>
<xsl:template match="EmployeeDetails/Department">
<xsl:value-of select ="@Dname"/>
<br/>
</xsl:template>
</xsl:stylesheet>
Within the above code, you can observe that I am using “@Dname,” which stands for “attribute Dname.” The following is the second approach we can use to accomplish our goal (using the “xsl:for-each” construct).
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<b>
<xsl:for-each select="EmployeeDetails/Department">
<xsl:value-of select="@Dname"/>
<br/>
</xsl:for-each>
</b>
</xsl:template>
</xsl:stylesheet>
This third approach is also valid:
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<b>
<xsl:apply-templates select ="EmployeeDetails/Department/@Dname"/>
</b>
</xsl:template>
<xsl:template match="EmployeeDetails/Department/@Dname">
<xsl:value-of select ="."/>
<br/>
</xsl:template>
</xsl:stylesheet>
In any of the above cases, when the XSLT gets executed, the transformation looks something like the following:
<b>
Accounting<br />
Sales<br />
Research<br />
</b>
Next: Retrieving all values of a particular attribute at any level of hierarchy (or path) >>
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