LISTSERV mailing list manager LISTSERV 16.0

Help for XML-L Archives


XML-L Archives

XML-L Archives


XML-L@LISTSERV.HEANET.IE


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

XML-L Home

XML-L Home

XML-L  December 2000

XML-L December 2000

Subject:

Re: XSL question

From:

"John E. Simpson" <[log in to unmask]>

Reply-To:

General discussion of Extensible Markup Language <[log in to unmask]>

Date:

Wed, 13 Dec 2000 09:35:46 -0500

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (144 lines)

At 06:12 PM 12/13/2000 +0530, Verma, Sanjay wrote:
>My xsl file is
>
><?xml version="1.0" ?>
><xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
>version="1.0">
><xsl:output method="html"/>
><xsl:template match="/">
>
>
></xsl:template>
></xsl:stylesheet>

You're off to a good start with your <xsl:stylesheet> element -- using the
version attribute and the correct (most up-to-date) namespace declaration.
However, there's only one template rule in your stylesheet. Translated into
English, the template rule tells the XSLT processor (MSXML/IE5, Saxon,
whatever): "When you find the source document's root node, do nothing."

(Actually, it's not quite "nothing." There's whitespace between the
xsl:template's start and end tags... but ONLY whitespace. No matter how
your XSLT processor handles a whitespace-only result tree, the practical
effect when viewed in a browser is the same: whitespace only.)

First, try this. Replace the empty template rule above with one that looks
like this:

    <xsl:template match="/">
       <html>
          <head>
             <title>Regional Sales</title>
          </head>
          <body>
             <xsl:apply-templates/>
          </body>
       </html>
    </xsl:template>

What this template tells the processor is: "When you find the source
document's root node, create [i.e., 'instantiate'] in the result tree
[i.e., what the browser will display] the general framework of an HTML
document, including html, head, title, and body elements. *Within the
result tree's body element*, look for and process all template rules
applying to children of the context node [in this case, the root node]; if
there are no explicit template rules for processing those children, then
use any built-in template rules in effect."

What IE will show you as a result is a document window with the title
"Regional Sales," and whose content consists of all the text nodes in the
XML source document, sort of butted up against one another in a big string.

What's going on at this point is that, in the absence of any template rules
for processing element and text nodes found in the source document, the
built-in rules kick in. The applicable built-in rules look something like this:

    <!-- [1] For element nodes: -->
    <xsl:template match="*">
       <xsl:apply-templates/>
    </xsl:template>

    <!-- [2] For text nodes: -->
    <xsl:template match="text()">
       <xsl:value-of select="."/>
    </xsl:template>

Template rule [1] says: "When you find an element in the source tree,
regardless of its name [note the wildcard asterisk where you'd normally see
a specific name], look for and apply all template rules (including built-in
ones) for all children of this element."

Your source document's non-empty elements have two kinds of children: other
elements, and text nodes. The other elements will be recursively processed
by this built-in rule [1]. As for text nodes, they'll be handled by
built-in rule [2], which says: "When you find a text node in the source
tree, simply transfer its contents to the result tree."

Bottom line is that (to this point) what you see in the browser is the same
as if it had been delivered a plain-old HTML document which looks like this:
    <html>
       <head>
          <title>Regional Sales</title>
       </head>
       <body>
          Northwind.comRegional Sales ReportSales report for the West
Coast, Central [etc., through:] East Coast
       </body>
    </html>

In order to make this a little more presentable, you'd want to provide
template rules for specific element types. For instance:

    <xsl:template match="sales">
       <h1><xsl:value-of select="summary/heading"/></h1>
       <h2><xsl:value-of select="summary/subhead"/></h2>
       <h4><xsl:value-of select="summary/description"</h4>
    </xsl:template>

    <xsl:template match="data">
       <table border="1">
          <xsl:apply-templates/>
       </table>
    </xsl:template>

    <xsl:template match="region">
       <tr>
          <th colspan="4"><xsl:value-of select="name"/><th>
       </tr>
       <tr>
          <th>Q1</th>
          <th>Q2</th>
          <th>Q3</th>
          <th>Q4</th>
       </tr>
       <tr>
          <xsl:for-each select="quarter">
               <td><xsl:value-of select="@widgets-sold"/></td>
          </xsl:for-each>
       /tr>
    </xsl:template>

I'll leave for you the exercise of figuring out what each of these template
rules does. :)

There's one other template rule I like to include in my stylesheets, and
this is strictly a matter of taste:
    <xsl:template match="* | text()"/>
What this does is basically to override the built-in template rules for
elements and text nodes, by *suppressing* all text output from any of those
nodes. Thus, the only output (source tree) I'll see is the output I
explicitly put there with specific template rules.

Hope that helps.

P.S. I haven't tested any of the above XSLT code, but it should be okay
except possibly for stray typos. Also note that there are any number of
possible result trees which can reasonably be generated for a given source
tree. For instance, the above builds one table which contains all regions'
results; you could just as well build a separate table for each region, or
whatever.

===============================================================
John E. Simpson               | "He asked me if I knew what
http://www.flixml.org         | time it was. I said, 'Yes, but
XML Q&A: http://www.xml.com   | not right now.'" (Steven Wright)

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

February 2017
August 2016
June 2016
March 2016
January 2016
July 2014
April 2014
January 2014
July 2013
February 2013
September 2012
August 2012
October 2011
August 2011
June 2011
January 2011
November 2010
October 2010
July 2010
June 2010
March 2010
February 2010
January 2010
November 2009
September 2009
August 2009
July 2009
May 2009
March 2009
December 2008
October 2008
August 2008
May 2008
March 2008
February 2008
January 2008
December 2007
October 2007
August 2007
June 2007
March 2007
January 2007
December 2006
September 2006
July 2006
June 2006
April 2006
February 2006
January 2006
November 2005
September 2005
August 2005
July 2005
June 2005
May 2005
March 2005
January 2005
October 2004
August 2004
July 2004
June 2004
May 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003
December 2002
November 2002
October 2002
September 2002
August 2002
July 2002
June 2002
May 2002
April 2002
March 2002
February 2002
January 2002
December 2001
November 2001
October 2001
September 2001
August 2001
July 2001
June 2001
May 2001
April 2001
March 2001
February 2001
January 2001
December 2000
November 2000
October 2000
September 2000
August 2000
July 2000
June 2000
May 2000
April 2000
March 2000
February 2000
January 2000
December 1999
November 1999
October 1999
September 1999
August 1999
July 1999
June 1999
May 1999
April 1999
March 1999
February 1999
January 1999
December 1998
November 1998
October 1998
September 1998
August 1998
July 1998
June 1998
May 1998
April 1998
March 1998
February 1998
December 1997
November 1997
October 1997

ATOM RSS1 RSS2



LISTSERV.HEANET.IE

Secured by F-Secure Anti-Virus CataList Email List Search Powered by the LISTSERV Email List Manager