* Re: ANNOUNCE: XIA 1.00 Now Available
2005-03-06 13:38 ANNOUNCE: XIA 1.00 Now Available Marc A. Criley
2005-03-06 14:12 ` Marc A. Criley
@ 2005-03-10 14:24 ` Marc A. Criley
1 sibling, 0 replies; 3+ messages in thread
From: Marc A. Criley @ 2005-03-10 14:24 UTC (permalink / raw)
Marc A. Criley wrote:
> Version 1.00 of XIA (XPath In Ada) is now available on the McKae
> Technologies website at www.mckae.com/xia.html.
>
> This version of XIA completes the initial Ada implementation and release
> of the XPath 1.0 specification.
(Since this is my thread, I'm just going to keep on adding to it :-)
Okay, so you now have a native Ada implementation for XPath querying, so
what?
Well, Ada programmers in general like to work with software written in
Ada so they can look at it and more easily see what's going on, hence
writing XIA in Ada.
What does XPath buy me?
If you're working with XML documents, there are two standard approaches
for interacting with such documents, SAX and DOM.
SAX is oriented towards stream-oriented processing, meaning that you
process the contents of a document as it streams through your
application, there's no innate retention of the content once it's been
processed. This is good for doing things like transformations and
especially when working with documents of very large size.
DOM is tree-oriented access to the document, where the entire XML
document is loaded into an in-memory tree, and can now be walked
through, randomly accessed, manipulated, and even easily written back
out to a document.
Thanks for the info, but what does XPath buy me?
XPath is a standard approach for selecting nodes out of an XML document.
Instead of you having to write your own code to go and search for
nodes (elements and/or attributes) of interest, you write an XPath query
and bang it up against the document--and back comes a list of nodes that
meet the query's criteria.
XPath can work with both DOM and SAX approaches to XML document
processing, but SAX, being a 1-way stream oriented mechanism, means that
you either have to restrict yourself to an XPath subset (eliminating
queries that involve elements that would have already gone past), or do
some gnarly query preprocessing, along with maintenance and pruning of
lists of potential node matches, etc.
Due to the latter complications of dealing with SAX interaction, XIA
works strictly with the DOM model of XML document access.
Hope this was helpful...
www.mckae.com/xia.html
Marc A. Criley
McKae Technologies
www.mckae.com
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