RE: regarding strip-space

Here is a good example that may help you understand whitespace and the
way it is handled by some processors:

Take this xml:

  <?xml version="1.0"?>
  <root>
    <node>Hello</node>
    <node>World</node>
  </root>

Here you have the root element, with two <node> elements and some
whitespace (carriage returns, non-breaking-spaces etc) as its children.
Without the whitespace as children, it would look like this:

  <?xml version="1.0"?>
  <root><node>Hello</node><node>World</node></root>

This whitespace is pretty insignificant here - its only to make the xml
more readable.  However, in certain cases you will want to handle this
whitespace, which is where <xsl:strip-space> and <xsl:preserve-space>
come in.

To highlight how these work, try applying this stylesheet to the above
xml:

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

  <xsl:template match="root">
    <xsl:value-of select="."/>
  </xsl:template>

  </xsl:stylesheet>

Using <xsl:value-of select="."/> on the <root> element will give you the
string value of all of its children, including the whitespace:

  <?xml version="1.0" encoding="utf-8"?>
    Hello
    World

This whitespace was only to make the xml more readable, and not wanted
in the output.  To get rid of this, you can use <xsl:strip-space
elements="*"/> :

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

  <xsl:strip-space elements="*"/>

  <xsl:template match="root">
    <xsl:value-of select="."/>
  </xsl:template>

  </xsl:stylesheet>

(You can be more specific than '*' but for now this will do)

So you output will now look like this:

  <?xml version="1.0" encoding="utf-8"?>HelloWorld

Note all on one line - no whitespace (carriage returns, nbsp's)

You can use this in combination with <xsl:preserve-space> to control the
whitespace that gets copied to your output tree.  <xsl:preserve-space>
has a higher priority than <xsl:strip-space>, so you can strip-space on
* and then list the elements you want to keep the whitespace for:

  <xsl:strip-space elements="*">
  <xsl:preserve-space elements="keepme"/>

on this data:

  <remove>
    <node>Hello</node>
    <node>World</node>
  </remove>
  <keepme>
    <node>foo</node>
    <node>bar</node>
  </keepme>

would give you:

<?xml version="1.0" encoding="utf-8"?>HelloWorld
    foo
    bar

The carriage returns within <keepme> have been copied to the output
tree, whereas those within <remove> have been stripped.

<note>
MSXML effectively does a 'strip-space' during parse time, so the xslt
processor side of it doesn't ever get to see this kind of whitespace,
rendering these two commands useless.
</note> 


The joys of whitespace...

cheers
andrew





-----Original Message-----
From: subbu@xxxxxxxxxxxx [mailto:subbu@xxxxxxxxxxxx]
Sent: 16 July 2002 13:34
To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
Subject:  regarding strip-space



hi
I read in the XSLT Reference that xsl:strip-space would actually remove
the 
whitespace-only text nodes from the source.
My question is ..( sorry its a bit weird)
1.what is a whitespace-only node?? ( is it an empty element of kind 
<myel></myel>)??

2.If i have empty elements like what i have shown above(<myel></myel>)
and if i have to pick all the myel elements which have some text in it (
non 
empty ) then , i beleive the only way to do it is through a condition
<xsl:for-each select = //myel[not(string-length(.) = 0)]">
is it true??

or are there any better ways to do it?

Subbu


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