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From "HERRICK, CHUCK (SBCSI)" <CH6...@momail.sbc.com>
Subject RE: Attribute and Element
Date Thu, 18 May 2000 22:53:09 GMT
The fact that an attribute can not have a child element should right off the
top tell you that if you're modeling either IS A or HAS A data relationships
with attributes, you've made a terrible blunder.

Attributes are a way to pass information to the handling program downstream,
not a way to model your data relationships.

Look at Schemas and pray we all get to them before we have to live too much
longer with DTDs. Schemas make all this confusion go away (well, almost :-)

-----Original Message-----
From: mdelagra@us.britannica.com [mailto:mdelagra@us.britannica.com]
Sent: Thursday, May 18, 2000 5:38 PM
To: general@xml.apache.org
Subject: RE: Attribute and Element


Also, if you're XML document needs to be high performance, attributes are
much more efficient.  The main drawback of an attribute is that it is a
simple string; it should never be long, and it can never contain elements.
If you think you may reuse the concept of "Price" in other contexts or want
to assign child elements, it makes more sense to define it as an element.

> -----Original Message-----
> From: Rob Wygand [mailto:rob@wygand.com]
> Sent: Thursday, May 18, 2000 5:07 PM
> To: general@xml.apache.org
> Subject: Re: Attribute and Element
> 
> 
> This is a cause of much debate and consternation for me. What I've
> generally decided is that the relationship come down to IS A 
> and HAS A.
> If the thing in question is an integral part of the object represented
> by the parent, then make it an attribute. However, if it's another
> seperate 'object' and the parent known owns it, then I make it a child
> node.
> 
> This is all still highly subjective, but I always try to think how I'd
> model this in an RDBMS and then use a similar scheme.
> 
> An example is...
> 
> <EmailMessage>
>   <Headers From="rob@wygand.com" 
>            To="foo@bar.com" 
>            Date="10-10-10T10:10:10Z"
>            Subjec"Hello, there foo"/>
>   <Body content_type="text/plain" content_encoding="7bit">
>      Test message!
>   </Body>
>   <Attachment content_type="image/gif" name="myhouse.jpg"
> content_encoding="base64">
>  
> AAlLJSLKFJLKFJSLJFLKSJFLSKJFLSKJFLKFJSLDJFLSJDFLKSJFLSJFLKSDJF
> SLKFJLFJSDLKJLSJFLS
>  
> LJSLKFJLKFJSLJFLKSJFLSKJFLSKJFLKFJSLDJFLSJDFLKSJFLSJFLKSDJFSLK
> FJLFJSDLKJLSJFLSAA0
>                                                                      
> [... etc ...]
>   </Attachment>
> </EmailMessage>
> 
> 
> Cheun N Chong wrote:
> >         The confusion I am having now is, should I put the Price (or
> > ValidBefore) as an attribute of the Ticket or put it as an 
> element under
> > the Ticket. What is the difference, and what is the benefits?
> >
> 
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