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Re: Options for dealing with IDs

From: Chris Lilley <chris@w3.org>
Date: Fri, 10 Jan 2003 21:23:43 +0100
Message-ID: <36328207281.20030110212343@w3.org>
To: www-tag@w3.org, Paul Grosso <pgrosso@arbortext.com>

On Friday, January 10, 2003, 5:11:16 PM, Paul wrote:


PG> At 16:51 2003 01 10 +0100, Chris Lilley wrote:
>>the number of applications that need to know IDness is very large, so
>>requiring them to fetch an external DTD is to heavy and requiring all
>>instances to start with a substantial internal subset of 60 or so
>><!ATTLIST foo ID #IMPLIED> for all values of foo is also too heavy.

PG> You mean (something like) <!ATTLIST foo id ID #IMPLIED>.

Snort. Yes, clearly. Sorry.   Or rather the output of

for i in <element-names> do
 print <!ATTLIST i id ID #IMPLIED>
end

>>What is needed is a simple and lightweight method of determining
>>IDness for well-formed instances. Making it upwards compatible when
>>either of DTD or Schema validation (or both) is then performed, is
>>clearly desirable for interoperability.


PG> Though I don't know how I feel about this, I believe there is a
PG> variant that isn't included in any of your previous scenarios, Chris.

That is entirely possible.

PG> XML could pick up the #ALL capability defined five years ago in the 
PG> SGML TC2 [1] that allows a declaration of the form:

PG>   <!ATTLIST #ALL id ID #IMPLIED>

PG> in the internal subset to add an 'id' attribute of type ID to all elements.

Great suggestion. That would make the 'always declare IDs in the
internal subset' option tractable, for common cases. Currently all XML
processors are require to read the internal subset, yes?

It would not help applications that use different names for ID
attributes on different elements, or multinamespace documents that do
so, so it is rather more like option 5 instead of option 6. It would
also not help in the SOAP case where the internal subset is forbidden
by the language definition.

But I agree it is a possible solution and furthermore, one that
benefits from prior experience from the SGML community.

PG> paul

PG> [1] http://www.ornl.gov/sgml/wg8/document/1955.htm section K.4.4 Attribute definitions



-- 
 Chris                            mailto:chris@w3.org
Received on Friday, 10 January 2003 15:23:48 GMT

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