Re: <input> for <pipeline>

On 10/5/07, Norman Walsh <ndw@nwalsh.com> wrote:
> By way of an attempt to justify allowing default bindings for p:input
> on p:pipeline, consider this pipeline:
>
> <p:pipeline xmlns:p="http://www.w3.org/2007/03/xproc"
>             xmlns:px="http://xproc.org/2007/03/xproc/ex">
> <p:input port="source">
>   <p:document href="langspec.xml"/>
> </p:input>
>
> <p:xinclude name="xinclude"/>
>
> <p:validate-relax-ng name="validate">
>   <p:input port="schema">
>     <p:document href="../schema/dbspec.rng"/>
>   </p:input>
> </p:validate-relax-ng>
>
> <p:xslt2 name="style">
>   <p:input port="stylesheet">
>     <p:document href="../style/dbspec.xsl"/>
>   </p:input>
> </p:xslt2>
>
> <p:store name="store">
>   <p:option name="href" value="langspec.html"/>
> </p:store>
>
> </p:pipeline>
>
> It processes the XProc language specification. If you don't provide any
> binding for "source", its default behavior is to process langspec.xml.
>
> If, however, I want to process some variant draft, I can easily do so
> by binding "source" to some other document when I call the pipeline.
>
> This seems like useful behavior to me.
>
> With respect to called pipelines, I think I could be persuaded to go
> either way. That is, for non-primary inputs either require a binding
> as I believe is the case today or allow a defaulted binding to apply.
> (With respect to unbound primary inputs, there is no question, that
> will be bound to the default readable port.)
>
> But I'm not likely to lie down in the road over it, I guess, if the
> consensus of the WG is to remove this feature.
>


Personnaly, I'm strongly opposed to allow to NOT bing a primary input ports

Apart from that, I find it a useful a not so problematic feature

But It would mean that

* <!-- nothing --> (defaulted content)
* <p:input port="secondary"/> (default binding)
* <p:input port="secondary"><p:empty/></p:input> (empty content)

could give three different result from now on (Norm it was one of your
earlier concern).

Furthermore, it gives us one more use case for cardinality zero-or-one

Mohamed
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Received on Friday, 5 October 2007 16:40:51 UTC