Node Interface for use in a Source by a Transformer

[Da...@lotus.com]

Any help would be greatly appreciated!


Questions:

Is there some defined subset of the Node interface that I can implement if 
I only want it to be used in a DOMSource by a Transformer?

Is it sufficient to implement only the Node interface for the root and all 
descendants or are any subinterfaces of Node expected?



Background and Details:

We have a large proprietary (non-relational) database.  The data is 
hierarchically related and is well suited to be exported as XML.  I would 
like to front end our database with the XALAN-Java 2.0 XSLT processor, 
allowing the user to specify XSLT to access only the XML they want (and of 
course transform it if they wish).  There is too much data to export the 
entire database as XML so I plan on using a DOMSource as input and 
generate Node objects on demand.

It is clear that not all the methods of the Node interface are needed for 
use in a Source by a Transformer, e.g. appendChild() or removeChild().  I 
would like to implement as little of the Node interface as possible.  Also 
I am concerned that the Node interface alone is not sufficient.

I could of course just read the source code, but if anyone already knows 
the answer that would certainly help me. I was even hoping there was a 
sanctioned interface or list of methods that I could implement, knowing it 
was safe to ignore the others now and in the future.

David Osofsky
Software Architect
Document Management Products
Knowledge Management Products Group

Lotus Development Corporation
One Rogers Street
Cambridge, Massachusetts 02142
USA 

Phone/fax: +1- 617.693.5748 / +1-617.225.8072
notes:         David Osofsky/CAM/Lotus@Lotus
internet:      david_osofsky@lotus.com 

RE: Node Interface for use in a Source by a Transformer

[Pradeep Sinha <pr...@intertechsys.com>]

I reviewed some of the same issues in the context of fronting a relational
data base with XSL queries and transforms. The one thing that might help is
looking through the org.apache.xalan.lib.sql package. It implements nodes on
the fly for accessing a resultSet in the context of xpaths. A sample does
not a spec make, however ! Please post info if you find any answers  .

Pradeep

 -----Original Message-----
From: xalan-dev-return-7934-pradeep=intertechsys.com@xml.apache.org
[mailto:xalan-dev-return-7934-pradeep=intertechsys.com@xml.apache.org]On
Behalf Of David_Osofsky@lotus.com
Sent: Friday, January 19, 2001 12:55 PM
To: xalan-dev@xml.apache.org
Subject: Node Interface for use in a Source by a Transformer



  Any help would be greatly appreciated!


  Questions:

  Is there some defined subset of the Node interface that I can implement if
I only want it to be used in a DOMSource by a Transformer?

  Is it sufficient to implement only the Node interface for the root and all
descendants or are any subinterfaces of Node expected?



  Background and Details:

  We have a large proprietary (non-relational) database.  The data is
hierarchically related and is well suited to be exported as XML.  I would
like to front end our database with the XALAN-Java 2.0 XSLT processor,
allowing the user to specify XSLT to access only the XML they want (and of
course transform it if they wish).  There is too much data to export the
entire database as XML so I plan on using a DOMSource as input and generate
Node objects on demand.

  It is clear that not all the methods of the Node interface are needed for
use in a Source by a Transformer, e.g. appendChild() or removeChild().  I
would like to implement as little of the Node interface as possible.  Also I
am concerned that the Node interface alone is not sufficient.

  I could of course just read the source code, but if anyone already knows
the answer that would certainly help me. I was even hoping there was a
sanctioned interface or list of methods that I could implement, knowing it
was safe to ignore the others now and in the future.
------------------------------------------------------------------------

        David Osofsky
        Software Architect
        Document Management Products
        Knowledge Management Products Group

------------------------------------------------------------------------

        Lotus Development Corporation
        One Rogers Street
        Cambridge, Massachusetts 02142
        USA

------------------------------------------------------------------------

        Phone/fax: +1- 617.693.5748 / +1-617.225.8072
        notes:         David Osofsky/CAM/Lotus@Lotus
        internet:      david_osofsky@lotus.com