Re: [docbook-apps] Stripping comments

["Bob Stayton" <bobs@sagehill.net>]

You could use XSLT, but you might not like the results.  8^)
You start with an identity stylesheet such as the following:

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

<xsl:output indent="no"/>

<xsl:template match="node()|@*">
    <xsl:copy>
      <xsl:apply-templates select="@*"/>
      <xsl:apply-templates/>
   </xsl:copy>
</xsl:template>

</xsl:stylesheet>

Then you add a template to strip out comments:

<xsl:template match="comment()"/>

There are several problems with using XSLT though:

1.  Entity references are expanded, not preserved as entity references. 
You can't hide them in XSLT because the parser expands them before the 
stylesheet sees them.

2.  Any DOCTYPE declaration is removed.  You have to copy your doctype 
public and system identifiers to the xsl:output element's doctype-public 
and doctype-system attributes.  The stylesheet can't do it, because the 
DOCTYPE is not accessible to XPath.  Any internal DTD subset is lost, as 
there is no way for xsl:output to specify it.

3.  Default DocBook attributes are added.  You will end up with a lot of 
moreinfo="none" attributes on elements like literal.

4.  The output will differ in other ways because the XML is parsed and then 
re-serialized: attribute order may be different, empty elements may be 
expressed differently, character references will become native UTF-8 
(unless you specify a different output encoding).  These differences will 
show up in a text diff program, but not an XML-aware differencing program.

Generally, I use Perl for such filtering.  The XML comment string is a well 
defined regular expression, and Perl doesn't mess with any XML stuff.  I 
read the entire file into a single string, globally replace comments with 
nothing, and then print the string.

Bob Stayton
Sagehill Enterprises
DocBook Consulting
bobs@sagehill.net


----- Original Message ----- 
From: "Paul Moloney" <paul_moloney@hotmail.com>
To: <docbook-apps@lists.oasis-open.org>
Sent: Thursday, March 29, 2007 6:45 AM
Subject: [docbook-apps] Stripping comments


>
> One task I have it to package our source XML files for use by 
> integrators;
> one thing I'd like to do is first strip the comments from these files as
> they may contain sensitive information.
>
> I was thinking that this could be done by processing each file through 
> Saxon
> using a stylesheet which strips out comments and outputs the XML again. 
> But
> rather than risk reinventing the wheel, I was wondering if anyone out 
> there
> has implemented a DocBook comment stripper in their build process?
>
> Thanks,
>
> P.
> -- 
> View this message in context: 
> http://www.nabble.com/Stripping-comments-tf3486783.html#a9734912
> Sent from the docbook apps mailing list archive at Nabble.com.
>
>
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