Re: Fresnel vocabulary question

From: Ryan Lee <>
Date: Mon, 27 Feb 2006 17:00:28 -0500

Reto Bachmann-Gmür wrote:
> Emmanuel Pietriga schrieb:
>> Ryan Lee wrote:
>>> Reto Bachmann-Gmür wrote:
>>>> Hello
>>>> I've read . It says
>>>> "The result of applying a lens or a group of lenses to an RDF graph
>>>> is an ordered tree of RDF nodes" however, while I find information
>>>> how the properties are ordered, I found nothing on how the
>>>> "top-level" resources are ordered, how does the output of the
>>>> FOAF-Example in 1.1 looks like, when applied to a graph with several
>>>> foaf:PersonS? Also what's the order of the the properties of same
>>>> type (multiple foaf:nameS or foaf:knowS).
>>>> I probably just missed something, so I would be thankful for a pointer.
>>>> reto
>>> Hello Reto,
>>> We opted to avoid the complexity of ordering resources or values in
>>> Fresnel core. We're open to suggestions on how best to handle the issue
>>> (extensions, revise core, etc.), it's just that at that time we had
>>> enough other issues on our plate to deal with without getting into how
>>> to describe the myriad ways of ordering things. Our sense then was
>>> basically to let the implementing application handle ordering.
>>> (So you didn't miss anything.)
>> If such an ordering is considered useful (for top-level resources, I
>> mean), I would rather see it in an extension vocabulary.
> Why not? Maybe the fresnel manual should speak about "applying a lens or
> a group of lenses to" an RDF-Resource rather than an RDF-Graph. But how
> are non-top level resources ordered, say the objects of multiple
> foaf:knows properties?

For those who didn't agree that ordering should be part of Fresnel, the
rationale was something like:

  - You can use an rdf:List to accomplish ordering; there is opportunity
before you hand your data to the Fresnel engine to slice and dice it
into the order you want before setting Fresnel loose on making it look

  - You can order it after the fact (e.g., javascript client ordering in
tables) as well, perhaps based on data you wouldn't necessarily know
before Fresnel touched it - the combined labels that come out of Fresnel
formatting, which property value is actually used in alternate or merged
properties. Clearly this could also be handled at the Fresnel stage, but...

  - I'm repeating myself - it seems difficult to provide a generic way
of talking about ordering even in a limited core sense. Alphabetical
ordering counting definite articles or not? Based on which character
set and which language's interpretation of ordering for that character
set? What if there is no particular sense of alphabetical order in
another language? At this point, we didn't feel we could enumerate that
core set in such a way that it would really cross applications.

Before Fresnel made its way into Longwell2, LW2 had options available
for re-ordering result sets in the client GUI. I've left it as is, and
for the moment, Fresnel only renders one result at a time - as you said,
rendering RDF resources as opposed to graphs (though the results from
Fresnel aren't necessarily the same as those used by the ordering system
- another point at which the two need to be more closely tied).

Ordering of non-top level results is also intended to be application

Thoughts? Would you be at all interested in drafting a quick conceptual
ordering vocabulary?

Ryan Lee       
W3C Research Engineer    +1.617.253.5327
Received on Mon Feb 27 2006 - 21:59:23 EST

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