Forum OpenACS Q&A: XML on Tcl

1: XML on Tcl

Posted by Jun Yamog on 08/30/01 03:01 PM

Hi,

Is ns_xml the best way to have XML capabilities in aolserver? I have
used ns_xml + Ben's xml procs. They are ok but is there any better
solution?

How about trying to embed this to the aolserver tcl? Is this better
or having a wrapper (ns_xml) that use libxml2 is the best approach.

http://sourceforge.net/projects/tclxml

Jun

2: Response to XML on Tcl (response to 1)

Posted by Don Baccus on 08/30/01 03:22 PM

I personally like having extensions of this sort implemented as modules, such as ns_xml. The problems with embedding such things in AOLserver and its Tcl interpreter include the fact that

You'd have to get the aolserver.com/opennsd folks to agree to embed the changes
Maintenance is a problem - whenever the Tcl interpreter changes internally you might be faced with having to rewrite your embedded code.
Maintenance is (again) a problem - releasing fixes/enhancements to the XML code would have to be synchronized to the AOLserver release cycle. Interim fixes/enhancements would have to be added via patches, and most folks are loath to patch a server in a production environment.
Footprint - those not using XML would still have it loaded into their server image, eating memory.

I'm sure there are other good reasons. fixes

3: Response to XML on Tcl (response to 1)

Posted by Jun Yamog on 08/30/01 03:34 PM

I think you are right modules is better than embeding stuff.

I have a general question given the fact that aD will now use Java and
no more Tcl do we have community members that will actively improve on:

- patches on Aolserver (Rob Mayoff's ad patches)
- Oracle driver (I think its Rob Mayoff too)
- ns_xml.

Will Rob Mayoff still participate on this? If not do we have people
who is capable of doing this stuff AND will give time for it?

Rob Mayoff if you get to read this it would be great if you can reply
on this.

Jun

4: Response to XML on Tcl (response to 1)

Posted by Don Baccus on 08/30/01 09:08 PM

Dave Bauer's worked on ns_xml and he's "one of us". I think Yon Derek
may've worked on it, too? Not sure, I've not paid much attention to ns_xml details, it has worked for me on the OpenACS 4 project and until we're further along, that's all I care to know about ns_xml.

We'll probably have to pick up the Oracle driver, though folks in the AOLserver community may help, too. It seems very solid, though, and I'm not terribly worried about it. When or if AOLserver switches over to using Tcl Objects internally we may want to work on both (PG and Oracle) RDBMS drivers to take advantage of this for efficiency reasons.

Rob's not working actively on AOLserver but is available for questions. He's helped Vinod Kurup rewrite ns_uuencode, which is broken in AOLserver+Tcl8, and needed by acs-mail if attachments are to be handled efficiently.

Also, the AOLserver situtation within AOL is
much brighter, with community relations being in much better shape and
with one of the original implementors (Jim Davidson) actively working on AOLserver 4.

5: Response to XML on Tcl (response to 1)

Posted by Dave Bauer on 08/31/01 01:46 AM

Ack. I have used ns_xml but I have no C skills yet.

I am impatiently waiting for the C versions of TclXML and TclDOM. I think they would be nice to also have as AOLserver modules.
TclXML has an interface that allows different XML parsers to be used.