Re: [xml-dev] Don’t create elements with simple co ntent and attribut

["G. Ken Holman" <gkholman@CraneSoftwrights.com>]

And:

"When Should I Use Elements, and When Should I Use Attributes?"
http://www.oasis-open.org/cover/elementsAndAttrs.html


At 2018-09-27 09:43 -0600, Uche Ogbuji wrote:
> "Principles of XML design: When to use elements versus attributes", 2004:
> <https://www.ibm.com/developerworks/library/x-eleatt/index.html>https://www.ibm.com/developerworks/library/x-eleatt/index.html
>
>
>
> On Thu, Sep 27, 2018 at 6:54 AM Costello, Roger 
> L. <<mailto:costello@mitre.org>costello@mitre.org> wrote:
>
> Hi Folks,
>
> I hold this to be the fundamental axiom of XML:
>
> � � � � � � � � �  Make the structure of data explicit.
>
> We accomplish that by adding a label (markup) to the data.
>
> There are various terms for this notion of 
> making the structure of data explicit: upconversion and uptranslation.
>
> Elements with simple content and attributes are 
> antithetical to the fundamental axiom of XML.
>
> Here is an element with simple content and an attribute:
>
> <Cost currency="USD">8.95</Cost>
>
> �
>
> The data USD is explicitly labeled. The label 
> indicates that USD is a currency.
>
> What about the data 8.95, is it labeled? No! It 
> is anonymous/unlabeled. Note: Cost is not the 
> label for 8.95; Cost is the label for the whole package.
>
> In my most recent post, I asked, “What is that 
> number (8.95)?” I received excellent 
> responses: 8.95 is a price, 8.95 is an amount, 
> etc. External knowledge was needed to label the 
> data. The need for external knowledge completely 
> contradicts the fundamental axiom of XML.
>
> Therefore, don’t create XML like this:
>
> <Cost currency="USD">8.95</Cost>
>
> instead, create XML like this:
>
> <Cost>
> � � �  <Currency>USD</Currency>
> � � �  <Amount>8.95</Amount>
> </Cost>
>
> �
>
> Do you agree?
>
> �
>
> /Roger
>
> �

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