[Nexus-developers] NeXus file conversions, NOBUGS

[Ray Osborn]

On 10/7/02 10:05 AM, "Mark Koennecke" <Mark.Koennecke at psi.ch> wrote:

>> 
>> Well, there is an XML file structure already defined - it is defined by
>> <http://www.neutron.anl.gov/nexus/NeXus_metaformat.html> and is implemented
>> in NXtoXML.  Since there has been no discussion about it since I announced
>> it on the NeXus mailing list, it is the de facto NeXus standard.  I have a
>> submitted a poster about it to NOBUGS, and we can discuss it at the NeXus
>> break-out session.
>> 
>> Of course, it doesn't define what goes in the files for particular
>> instruments.  That is, I presume, the subject of Steve King's and several
>> other people's NOBUGS contributions (I don't know about Farhi).
>> 
> 
> No, they have defined own versions of this mappings on their own.
> 

That is a shame because the XML format has been on the web for a while.  I
will post a question about it to the main list.  Thanks for letting me know.

>  Writing XML is the easy bit. Parsing it from a program is another
>  matter. You need to decide upon a XML parser and to learn how to
>  use it. This is the main reason why I think we should extend the
>  NeXus-API. And on the writing side, the use of NAPI would ensure
>  standard compliance without people having to read our format
>  definitions.  
> 

I have played about a bit with the libxml2 library, which is what Python
uses, I think.  It seems fairly trivial to write quite powerful programs, as
long as the underlying XML is well-formed.

Of course, we don't have true DTDs, so format validation will be more of a
problem.

Ray
-- 
Dr Ray Osborn                Tel: +1 (630) 252-9011
Materials Science Division   Fax: +1 (630) 252-7777
Argonne National Laboratory  E-mail: ROsborn at anl.gov
Argonne, IL 60439-4845