Question about tag and value

[mittra@juno.com]

Hello All,

I am a newbie to XML. I have the following question: how do I express
something in XML when the subsequent tag structures depends on the
value of a preceeding tag?

For example, when TAG2 has a value of 1, then TAG3 exists.

<TAG1>
<TAG2>1</TAG2>
<TAG3>some_valu e</TAG3>
</TAG1>

But when TAG2 has a value of 2, then TAG4 exists.

<TAG1>
<TAG2>2</TAG2>
<TAG4>some_valu e2</TAG4>
</TAG1>

Can the above two be combined into a single structure for TAG1?

Thanks for your insight.

[Philippe Poulard]

Re: Question about tag and value

hi,

mittra@juno.com a écrit :

>
if (TAG2 value is 1) then
<TAG3>some_valu e</TAG3>
else
<TAG4>some_valu e2</TAG4>
>
Perhaps, XML Schema does it?
>

this is exactly the way the Active Schema Language works : you can
define dynamically the content model that suits your needs, potentially
with the help of if-then-else statements

although ASL is experimental, it is implemented and works fine : you can
use it for your own needs if you don't have to share your own schemas
with third-party users ; ASL will allow you to express much more complex
constraints than legacy schema technologies can (DTD, W3C XML Schema,
RelaxNG, Schematron)

the implementation :

http://reflex.gforge.inria.fr/

the specification :

http://ns.inria.fr/active-tags/active-schema/active-schema.html

some tutorials :

http://reflex.gforge.inria.fr/tutorial-schemas.html

if you are new to XML, you'll have to understand namespaces in XML and
learn XPath before (which are widely used in XML technologies)

some courses :

http://disc.inria.fr/perso/philippe.poulard/cours/01c-xml-namespaces.pdf

http://disc.inria.fr/perso/philippe.poulard/cours/04-xml-xpath.pdf

....if you are new to french, you'll have to learn french before :)

--
Cordialement,

///
(. .)
--------ooO--(_)--Ooo--------
| Philippe Poulard |
-----------------------------

http://reflex.gforge.inria.fr/

Have the RefleX !