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Re: Attributes vs. Elements for Code values

From: Dan Vint <dvint@mindspring.com>
Date: Wed, 16 Apr 2003 18:33:24 -0700
Message-Id: <5.1.0.14.2.20030416183000.02e9dcf0@mail.dvint.com>
To: <xmlschema-dev@w3.org>

My organization has 2 schemas one with each approach. The issue is somewhat 
of a wash until you consider if you are providing an enumerated list of 
values. We have found it to be more flexible to have this as element 
content than as attribute content.

Originally coming from SGML, I would have pushed the attribute route 
because a DTD allowed some validation and control of a defined list where 
element content didn't. Schemas change that and allowed both the manage 
this issue, now it seems to be how you might want to extend a list of 
values that settle the discussion.


At 09:09 PM 4/16/2003 -0400, Jack Lindsey wrote:

>I want to use XML attributes to hold terse code values (e.g. "CA-BC", 
>"312120", "23") that are replaced by text in the language of your choice 
>from lookup tables in XML files (e.g. 
>"Colombie-Britannique",  "Breweries", "Cul-de-sac") when the XML data is 
>rendered on a web page.  However, some of my colleagues suffer from 
>generalized attribute phobia and want to do everything with XML 
>elements.  I don't see the danger.  Here are my pros and cons.  What do 
>you think?
>
>
>PRO
>1. Attributes mean much more compact XML data
>2. Processing attributes is much more efficient in XSLT and DOM
>3. Everybody does codes this way
>
>CON
>1. Other people's schemas can't just reuse your codes without also using 
>the surrounding element, unless you declare your code attributes globally? 
>Is that right?
>2. If an element can have multiple values of a code (like Disability in 
>Being in the example below), you have to create an element for it anyway 
>so it can occur multiply, and that is the worst option, performance-wise 
>(according to Scott Bonneau, XML Design handbook, p. 43)
>3. You don't get that nice XML schema diagrammatic documentation for your 
>attributes in XML Spy.
>
>
>Sample Data:
>
><Being beingSerialNumber="0002345" genderID="3" speciesID="42">
>   <BeingBirthDate>1980-04-13</BeingBirthDate>
>   <Disability disabilityID="17"/>
>   <Disability disabilityID="24"/>
>   <MedicalConditionNarrative medicalConditionID="23">Not responding to
>treatment.</MedicalConditionNarrative>
>   <MedicalConditionNarrative medicalConditionID="16">Clearing up
>nicely.</MedicalConditionNarrative>
></Being>
>
>Cheers Jack
Received on Wednesday, 16 April 2003 21:33:51 GMT

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