dolfin team mailing list archive

[Johan Jansson <johanjan@xxxxxxxxxxxxxxxx>]

On Tue, Feb 14, 2006 at 01:32:36PM -0600, Anders Logg wrote:
> On Tue, Feb 14, 2006 at 07:31:29PM +0100, Johan Jansson wrote:
> > On Mon, Feb 13, 2006 at 07:39:31PM -0600, Anders Logg wrote:
> > ...
> > > Maybe we can just move the writing of the header to the constructor
> > > and the writing of the footer to the destructor of XMLFile?
> > 
> > Hm, can we differentiate between reading and writing at that point?
> 
> No, I didn't think about that. How about two new (private) functions
> in XMLFile: writeHeader() and writeFooter() and a bool
> header_written and just implement as
> 
> void XMLFile::writeHeader()
> {
>   if ( header_written )
>     return;
> 
>   bla bla
> 
>   header_written = true;
> }
> 
> void XMLFile::writeFooter()
> {
>   if ( !header_written )
>     return;
> 
>   bla bla
> }
> 
> All the output operators then just need to call writeHeader() and
> writeFooter() is called by the destructor.
> 

Ok, this is probably a good solution, I can't think of any better at least.

> ok. Do you know if libxml2 has a function you can call to verify against a
> schema before parsing (without first building the DOM tree which may
> not fit in memory)?
> 
> /Anders
> 

Hm, this appears to be a limitation of libxml2:

http://mail.gnome.org/archives/xml/2005-January/msg00059.html

There exists other XML parsers which can do schema validation with the
SAX model however, Xerces for example:

http://xml.apache.org/xerces-c/schema.html#usage

I guess the situation right now is that we cannot do schema validation
for very large data files.

  Johan