- From: Romain Deltour <rdeltour@gmail.com>
- Date: Wed, 2 May 2012 00:48:00 +0200
- To: David Cramer <david@thingbag.net>
- Cc: XProc Dev <xproc-dev@w3.org>
As far as I understand this limitation on connections of p:variable @select is to avoid chicken-and-eggs situations where a variable could be based on the result of a step which itself uses the variable.
To clarify these situations, you need to wrap in a p:group the variable and all the steps depending on it:
…
<p:group>
<p:variable name="security" select="//c:param[@name =
'security']/@value" xmlns:c="http://www.w3.org/ns/xproc-step">
<p:pipe port="result" step="params"/>
</p:variable>
… other steps depending on $security …
</p:group>
<p:parameters name="params">
<p:input port="parameters">
<p:pipe port="parameters" step="main"/>
</p:input>
</p:parameters>
...
On 2 mai 2012, at 00:20, David Cramer wrote:
> Hi there,
> I'm in the same situation as Kevin Flynn describes in this thread:
>
> http://lists.w3.org/Archives/Public/xproc-dev/2010Jul/0002.html
>
> I've tried Vojtech's suggestion (though I've implemented it
> incorrectly) and now receive "XS0019:Variable binding to result on
> params not allowed." from Calabash:
>
> ...
> <p:variable name="security" select="//c:param[@name =
> 'security']/@value" xmlns:c="http://www.w3.org/ns/xproc-step">
> <p:pipe port="result" step="params"/>
> </p:variable>
>
> <p:parameters name="params">
> <p:input port="parameters">
> <p:pipe port="parameters" step="main"/>
> </p:input>
> </p:parameters>
> ...
>
> I'm quite puzzled as to how this should work, though it seems like
> extracting the value of a parameter into a variable for use in the
> pipeline should be a common task.
>
> Btw., I notice that search results to http://xprocbook.com now take
> you to empty pages. Is that intentional?
>
> Thanks,
> David
Received on Tuesday, 1 May 2012 22:48:32 UTC