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Re: Loading a parameter into a p:variable

From: David Cramer <david@thingbag.net>
Date: Tue, 01 May 2012 18:09:03 -0500
Message-ID: <4FA06D0F.5050701@thingbag.net>
To: Romain Deltour <rdeltour@gmail.com>
CC: XProc Dev <xproc-dev@w3.org>
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Hi Romain,
Thanks for that. The p:group was indeed important, but there was more
too. I ended up getting it to work using Geert Josten's ut:parameters
utility step [1] mentioned in this thread [2].

Regards,
David

[1]
https://github.com/grtjn/xproc-ebook-conv/blob/master/src/nl/grtjn/xproc/util/utils.xpl
[2]
http://web.archiveorange.com/archive/v/nvhn6tjvNdec7YLyd4yI

On 05/01/2012 05:48 PM, Romain Deltour wrote:
> 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
> 

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Received on Tuesday, 1 May 2012 23:09:34 GMT

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