OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

 


 

   RE: [xml-dev] XML and XPATH: How do they work?

[ Lists Home | Date Index | Thread Index ]

I'm not sure where XPath comes into this. As far as I can see the task you are engaged in is deciding how to represent your data in XML form. That's a question of data modelling, and then translating the data model into an XML schema or DTD (either explicit or "in your head"). XPath only comes into play when you start processing the data.
 
It seems your concern is how to define relationships between elements in your data. Some people believe strongly that every object in your model should have a URI and all relationships should be expressed using that URI. My personal view is, use whatever name or key arises naturally in the application. So don't do
 
 
instead do
 
<next>agapao</next>
 
since that's a sufficient identifier. You can worry about how to render this as a hyperlink when the time comes to consider transforming the XML into HTML.
 
I'm actually wondering whether this <next> element is needed in your XML at all? Does it hold any information that couldn't be reconstructed from other things in the XML, or is it just a navigation aid? If the latter, it may be better to leave it out entirely.
 
Michael Kay


From: Joe Schaffner [mailto:schaffner.joe@gmail.com]
Sent: 28 June 2005 11:35
To: xml-dev@lists.xml.org
Subject: [xml-dev] XML and XPATH: How do they work?

Hello Everybody,
 
I'm writing a dictionary of modern Greek verbs at http://modern-greek-verbs.tripod.com
 
The pages are linked using html anchors, like this:
 
-- from grafo.html
<a href="agapao.html"><i>Type</i></a>
'αγαπάω' is the next verb on the list of linked pages.
 
'Type' is the name of the list, a singularly-linked, circular list. There are three types, 'λύνω', 'αγαπάω' 'θεωρώ', and therefore three pages in this list.
 
I was wondering how such a list would appear in an xml version of the dictionary.
 
Do I do the lists in XPath?
 
HTML hyperlinks rely on the appearance/layout of the page. They're simply grouped together. A student knows which links to follow by looking at them.. but a processing program must know the name of the list.
 
Within each Type there are Models:
 
[<i>Model</i> <a href="ginomai.html">Prev</a> <a href="diablepo.html">Next</a>]
[<i>Model</i> <a href="bafo.html">Prev</a> <a href="anagrafo.html">Next</a>]

The list is hierarchical. Types are broken down into Models which can be broken down into sub-models.
 
The Models are nested from top to bottom. The definition is recursive...
 
This verb, γράφω, is part of the λύνω Type, and falls between other Models γίνομαι and διαβλέπω, in alphabetical order...
 
γράφω has two sub-models (verbs which are conjugated like γράφω): βάφω, and αναγράφω, the compounds of 'γράφω'...
 
Of course, 'γράφω' is also an instance of itself. It is a real verb, in addition to being a model for others.
 
I'm thinking something like this:
 
-- This file is 'grafo.xml' which is on the 'luno.xml' list
 
<type>
   <next>http://modern-greek-verbs.tripod.com/agapao.xml</next>
   <model>
      <prev>http://modern-greek-verbs.tripod.com/ginomai.xml</prev>
      <next>http://modern-greek-verbs.tripod.com/diablepo.xml</next>
     <model>
     </model>
   </model>
</type>
 
But I don't want to invent my own language. I'm hoping XPath will do the trick. I've been reading the documentation, which is very large, and I haven't really found any good examples.
 
Thanks. I'm sure you can save me a load of time.
 
Signed,
 
xml-newbie
 
 PS
 
(What is XLink?)




 

News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 2001 XML.org. This site is hosted by OASIS