Re: Enabling extension to counting of instances

I personally would use a function (predicate that decides if something
is a "chapter") passed as a parameter (function-item in 2.1 speak).


--
Cheers,
Dimitre Novatchev
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Truly great madness cannot be achieved without significant intelligence.
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To invent, you need a good imagination and a pile of junk
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Never fight an inanimate object
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You've achieved success in your field when you don't know whether what
you're doing is work or play




On Fri, Jan 8, 2010 at 7:08 AM, Eliot Kimber <ekimber@xxxxxxxxxxxx> wrote:
>
> In the DITA Open Toolkit one can deploy plugins that contribute new modules
> to a base set of XSLT transforms where the plugins typically provide
support
> for new (specialized markup).
>
> In many cases, the specialized markup needs to participate in base business
> logic by being added to arbitrary checks that represent some semantic type
> that is specific to the business logic where an element's mapping to that
> semantic type has to made explicitly.
>
> For example, in the context of generating print from DITA content, to
> determine chapter numbers you count the references from the DITA map that
> happen to represent chapters, where the determination of what is or isn't a
> "chapter reference" is arbitrary (meaning that the XSLT plugin for a given
> set of specialized reference elements has to say "tag X is a chapter
> reference" where tag X is unknown to the base chapter numbering logic and
> there's no way to infer from the markup itself that a given reference is or
> is not a chapter reference).
>
> The plugin can't simply override the numbering logic because that would
> break other plugins deployed to same Toolkit instance. Rather, plugins need
> to be able to contribute to the numbering logic so that all chapters are
> counted correctly.
>
> My design challenge then is to determine what is the best way to enable
this
> sort of unilateral contribution to things like numbering logic. In
> particular, typical code using <xsl:number/> with @count and @from won't
> work because there's no obvious way to extend the specification of what to
> count and what to count from.
>
> The only directly-provided XSLT extension mechanism I can think of is to
use
> modes where elements contribute nodes to a sequence that is then used for
> either counting or doing a boolean check.
>
> For example, to count chapter references you would have a mode
> "isChapterRef" and then use it like so:
>
> <xsl:variable name="chapterRefs"
> B as="element()*"
> >
> B <xsl:apply-templates mode="isChapterRef"
> B  select="$map//*[contains(@class, ' map/topicref ')]"/>
> </xsl:variable/>
>
> Where a typical isChapterRef template would be:
>
> <xsl:template mode="isChapterRef"
> B match="*[contains(@class, ' pubmap-d/chapterref ')]"
> >
> B <xsl:sequence select="."/>
> </xsl:template>
>
> So that the resulting value of $chapterRefs would be a list of elements
that
> have declared themselves to be chapter references.
>
> The $chapterRefs list can then be used for counting, boolean checks, etc.
>
> My question: is there a more efficient way to provide this sort of
> extensible arbitrary-type-to-semantic-type mapping?
>
> Thanks,
>
> Eliot
>
> --
> Eliot Kimber
> Senior Solutions Architect
> "Bringing Strategy, Content, and Technology Together"
> Main: 610.631.6770
> www.reallysi.com
> www.rsuitecms.com