W3C home > Mailing lists > Public > xproc-dev@w3.org > September 2008

Re: no roots in my pipeline

From: Norman Walsh <ndw@nwalsh.com>
Date: Mon, 22 Sep 2008 16:19:20 -0400
To: James Garriss <james@garriss.org>
Cc: XProc Dev <xproc-dev@w3.org>
Message-ID: <m21vzcj5mf.fsf@nwalsh.com>
James Garriss <james@garriss.org> writes:

> Well, I like to think that after working with Calabash for several days I've
> become a bit of an expert in the interesting but unmarketable skill of
> Calabash error message decoding.  But this one has me stumped:
> No roots in myPipeline

The order of the steps in your pipeline document doesn't actually have
any relationship with the order of the steps in your pipeline. (That's
not true if you rely on defaulting, but if you fully qualified
everything, you could put sibling steps in any order you wanted and it
wouldn't make any difference.)

The "No roots in myPipeline" message means that Calabash tried to analyze
the graph to figure out where the flow begins. It should only occur
if you have a loop in your pipeline.

However, I don't see a loop in here:

> <p:declare-step xmlns:p="http://www.w3.org/ns/xproc" name="myPipeline">
>     <p:input port="source">
>         <p:document href="BookStore.xml"/>
>     </p:input>
>     <p:output port="result">
>         <p:empty/>
>     </p:output>
>     <p:for-each>
>         <p:iteration-source select="//Book"/>
>         <p:output port="result">
>             <p:empty/>
>         </p:output>
>         <p:choose name="chooseFile">
>             <p:when test="count(//Author)>1">
>                 <p:store href="multipleAuthors.xml"/>
>             </p:when>
>             <p:when test="count(//Author)=1">
>                 <p:store href="singleAuthor.xml"/>
>             </p:when>
>             <p:otherwise>
>                 <p:store href="noAuthors.xml"/>
>             </p:otherwise>
>         </p:choose>
>     </p:for-each>
> </p:declare-step>

So it must be a bug. I'll take a look.

                                        Be seeing you,

Norman Walsh <ndw@nwalsh.com> | They that can give up essential liberty
http://nwalsh.com/            | to obtain a little temporary safety
                              | deserve neither liberty nor
                              | safety.--Benjamin Franklin

Received on Monday, 22 September 2008 20:20:04 UTC

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