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Re: CR draft ready for review

From: Norman Walsh <ndw@nwalsh.com>
Date: Fri, 21 Nov 2008 12:34:30 -0500
To: public-xml-processing-model-wg@w3.org
Message-ID: <m2fxllx9sp.fsf@nwalsh.com>
ht@inf.ed.ac.uk (Henry S. Thompson) writes:

> Toman_Vojtech writes:
>
>> I agree :) Personally I don't see any reason in forcing people to always
>> connect something to the primary (normal or parameter) input ports of
>> compound steps. They just hang there in the space, you don't have to use
>> them at all.
>
> Hold on.  What about the following [1]:
>
>   If no binding is provided for a primary input port, the input will
>   be bound to the default readable port. It is a static error
>   (err:XS0032) if no binding is provided and the default readable port
>   is undefined.
>
> I think this is as it should be.  I don't want to change it now.

Absolutely. That's not what's on the table. Consider this pipeline:

  <p:pipeline type="ex:mypipe">
    <p:identity>
      <p:input port="source">
        <p:inline><doc/></p:inline>
      </p:input>
    </p:identity>
  </p:pipeline>

The pipeline has a primary input port 'source' that's left dangling.
It's not used by p:identity so it just pours on the floor. That's what
we've been talking about.

The note about automatically binding p:sink to the parameter input
port is to avoid an error that doesn't exist: namely that it is an
error to leave input ports on a compound step unbound *inside the
container*.

The section you quoted above refers to this case:

  <p:pipeline>
    <ex:mypipe/>
  </p:pipeline>

It says that the input port on the ex:mypipe step will be bound to the
default readable port at the point of invocation. That is as it should
be.

> I do
> note that we do something similar for p:variable, p:with-option and
> p:with-param, but p:for-each/p:iteration-source and
> p:viewport/viewport-source don't say what happens if there is no
> binding and no DRP, and the discussion of XPath context specifies an
> empty document or undefined in that case.  We should probably make
> this all a bit more consistent.

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com> | Nothing will ever be attempted, if all
http://nwalsh.com/            | possible objections must be first
                              | overcome.--Dr. Johnson

Received on Friday, 21 November 2008 17:35:19 GMT

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