Re: [xslt] Embedded Stylesheets

[Daniel Veillard <veillard redhat com>]

On Sat, Aug 14, 2004 at 04:36:06AM -0700, Dave Hyatt wrote:
> On Aug 14, 2004, at 2:07 AM, Daniel Veillard wrote:
> 
> >  You also must ask for entity substitution so that libxml2 generate a
> >tree compatible with the XPath data model.
> 
> Ok.

  You need to pass XML_PARSE_NOCDATA | XML_PARSE_DTDATTR | XML_PARSE_NOENT
as the parser options for the XSLT and the XML to be sure to have a compliant
XPath data model representation in the tree.

> >I can't make sense of that code and the error is there. Why use a
> >Push parse when you have all data already in memory ?
> 
> I copied it from our XML+CSS code, which parses incrementally.  I can 
> obviously simplify the XSLT case, since that won't be incremental.  I 
> can change that.

   That will be way easier to maintain IMHO.

> >Why try to fool
> >the parser about encoding when libxml2 does implement the encoding
> >detection specified in appendix F of the XML specification ? Also
> >xmlCreatePushParserCtxt has encoding detection, you're redoing in
> >a likely untested way what libxml2 does reliably for ages. By doing
> >a forced cast to UTF16 you're breaking the encoding detection,
> >you're breaking performances, and you're likely to also break 
> >conformance
> >of the parser. Do not force a cast to UTF-16, it's really really bad !
> >Beware too of the decoupling from the HTTP engine and the XML parser,
> >you must read http://www.w3.org/TR/REC-xml/#sec-guessing and RFC 3023
> >you will have to pass the encoding as declared in the Content-Type
> >HTTP header.
> 
> I didn't write this particular code, but I believe that it was added to 
> fix a bug where XHTML with a BOM was not rendering correctly.  I'll try 
> to get you more details so that we can figure out what's going on.

  libxml2 will use and detect the BOM if present. But when you create
the Push parser context you should pass down the 4 first bytes of the
entity. Again this is all related to appendix F in the XML Rec. This is
tricky to fully get right, and I think bypassing the libxml2 code which
implement as exactly as possible that part of the spec is likely to break
the parser conformance.

Daniel

-- 
Daniel Veillard      | Red Hat Desktop team http://redhat.com/
veillard redhat com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
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