Hello John,

> Was there ever a good reason to embed validation information 
> in an instance document?

In education settings, where you are learning XML Schemas and doing validations one at a time using an IDE, it is convenient to embed schemaLocation within instance documents. And, in a closed environment where you are certain of who's sending the data, it may be convenient to embed schemaLocation within the instance document.

> Isn't that [embedding schemaLocation within instances] fundamentally backwards, 
> like trusting a thief because /he says/ he's not a thief?

Nicely stated!

/Roger


-----Original Message-----
From: John Snelson [mailto:john.snelson@o...] 
Sent: Tuesday, January 06, 2009 10:28 AM
To: Costello, Roger L.
Cc: 'xml-dev@l...'
Subject: Re: [xml-dev] Here's why it's not always a good idea to embed validation information (e.g., schemaLocation) in instance documents

Hi Roger,

Your presentation looks good, but I'm not sure it goes far enough. Was 
there ever a good reason to embed validation information in an instance 
document? Isn't that fundamentally backwards, like trusting a thief 
because /he says/ he's not a thief?

John

Costello, Roger L. wrote:
> Hi Folks,
> 
> I created a few Powerpoint slides that describe why it's not always a good idea to embed validation information in XML instance documents:
> 
> http://www.xfront.com/How-to-Specify-Validation-Information.ppt 
>  
> 
> Comments welcome.
> 
> /Roger

-- 
John Snelson, Oracle Corporation            http://snelson.org.uk/john
Berkeley DB XML:            http://oracle.com/database/berkeley-db/xml
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