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Re: Multiple and circular import/include

From: vivek agarwal <vivekorama@gmail.com>
Date: Thu, 3 Mar 2005 02:33:24 +0530
Message-ID: <2ac3993a05030213031db12565@mail.gmail.com>
To: Bob Schloss <rschloss@us.ibm.com>
Cc: xmlschema-dev@w3.org

Thanks Bob!
But, I still don't understand why the spec allows circular
references!? Is there a reason? or is it just like that?

Thanks,
Vivek.



On Tue, 1 Mar 2005 15:17:04 -0500, Bob Schloss <rschloss@us.ibm.com> wrote:
> 
> 
> Vivek,
> 
>       It is not an error to include the same schema document as the target
> of multiple <include> or <import> directives.
> 
>       Circular <include> or <import> directives are permitted.
> 
>       This is my mental model:
> 
> 1. The processor fetches your top-level schema document, and then keeps
> fetching any other schemas which are referenced through directives,
> transitively, but whenever it sees a directive targetting something it has
> already fetched, it doesn't fetch it again.  At the end of this process,
> the "actual schema" to be used for processing now exists in memory, having
> been merged from 1...n individual documents having the XML representation
> of XML Schema.
> 
> 2. Then the processor starts doing whatever it plans to do (validation of
> instance documents during parsing, generating Data Binding code, generating
> UI forms, or whatever).
> 
>       Because of subtleties associated with <redefine>, for the sanity of
> anyone who may have to maintain what you design, I would try to avoid
> circular redefines.
> 
>             Good Luck,
>             Bob
> 
> Scalable XML Infrastructure
> IBM Thomas J Watson Research Center
> Yorktown Heights, New York, USA
> http://www.research.ibm.com/XML
> 
>              vivek agarwal
>              <vivekorama@gmail
>              .com>                                                      To
>              Sent by:                  xmlschema-dev@w3.org
>              xmlschema-dev-req                                          cc
>              uest@w3.org
>                                                                    Subject
>                                        Multiple and circular
>              03/01/2005 01:41          import/include
>              AM
> 
>              Please respond to
>                vivek agarwal
> 
> 
> Hi,
> 
> I have a question on multiple and circular import/include each, if
> somebody could help.
> 
> Is it an error to import/include a schema more than once?
> A import/includes B1 and B2.
> Both B1, and B2, import/includes C.
> What is the expected behaviour of the processor in such a case?
> 
> Are circular import/includes allowed?
> A import/includes B, and B import/includes A?
> What is the expected behaviour of the processor in such a case?
> 
> Thanks,
> Vivek.
> 
>
Received on Wednesday, 2 March 2005 21:44:31 GMT

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