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Re: Sect 5.1 of future; Recommended JSON-LD context

From: Robert Sanderson <azaroth42@gmail.com>
Date: Mon, 28 Jan 2013 13:26:04 -0700
Message-ID: <CABevsUH-N-FAba6AGz5ET3Sx9NWs8xv6sZk+ndxFp__A-Y9iVA@mail.gmail.com>
Cc: public-openannotation <public-openannotation@w3.org>
On the logistics side, we don't currently have access to the namespace
in the W3 site, although it has been reserved for us.
This gives us two options:

1.  Use the W3C URI already, even though it's not actually there yet
2.  Use a different URI in www.openannotation.org (eg
/spec/core/context-20130204.json) in the document, and when we do get
the W3C URI then change it.  However, any annotations created with
this temporary URI would be out of date before too long (I hope)

I prefer option 1 as the context itself is given in the specification.

Also please, all, weigh in on Antoine's comment about the mapping for
has[Class] predicates and oa:styleClass.

Thanks!

Rob



On Mon, Jan 28, 2013 at 7:33 AM, James Smith <jgsmith@gmail.com> wrote:
> +1 for stable, versioned JSON-LD context documents
>
> Versioned contexts are useful when JSON-LD annotation data structures reference a context. If the context content changes, but the JSON-LD annotation data structure hasn't been updated to point to a different URL that holds the prior context that was used when building the JSON-LD data structure, then the JSON-LD might not represent the original annotation graph/concept/intent.
>
> So if we publish JSON-LD contexts for OA, we need to do so in a way that ensures they are stable so that people can reference them.
>
> A stable, versioned URL for a JSON-LD context is also useful when doing initial development/testing and you don't want to incorporate a full JSON-LD context processor into the application right away. Eventually, a proper JSON-LD application will need to process the context instead of keying off of the context URL.
>
> In some ways, the JSON-LD context can act like a namespace in XML, but it's more of a reference to a schema than a unique name. It's a mistake to treat the JSON-LD context as an XML namespace. As long as we're clear that we're not acting on the JSON-LD context URL as we would an XML namespace, I'm good with establishing well-defined, reference JSON-LD contexts for OA and what we might call OA application classes or modules.
>
> -- Jim
>
> On Jan 27, 2013, at 11:10 PM, Bob Morris <morris.bob@gmail.com> wrote:
>
>> Yes, exactly.  I do note that in the Provenance section there is an
>> Editor's note deferring modeling the version of OA itself.  That could
>> apply to this too, but that's not clear to me.
>>
>> In the case of the serialization as JSON-LD, there is a need for a
>> good contract between producer and consumer as to the actual
>> @context. The spec itself is adequate to that, since the @context is
>> listed in the spec, but whatever is arrived at for versioning the spec
>> has the chance of needing to change that, hence change its name.  A
>> scenario of slightly less importance is that as the OA spec itself may
>> continue evolve toward its possible state as a W3 Recommendation,
>> there are likely to be changes in the recommended @context.
>>
>>
>> On Sun, Jan 27, 2013 at 7:48 PM, Robert Sanderson <azaroth42@gmail.com> wrote:
>>> Hi Bob,
>>>
>>> Do you mean a version in the URI so that systems "know" that they can
>>> use their cached copy?
>>> So:  .../context-20130128.json  to distinguish from any future version?
>>>
>>> Thanks!
>>>
>>> Rob
>>>
>>>
>>> On Sun, Jan 27, 2013 at 1:44 PM, Bob Morris <morris.bob@gmail.com> wrote:
>>>> Sooner or later it might be good to assign a version to the
>>>> recommended context document and/or some other way stable designation
>>>> that does not depend on http dereferencing at  the time of
>>>> serialization or deserialization.
>>>>
>>>> Bob
>>>>
>>>> --
>>>> Robert A. Morris
>>>>
>>>> Emeritus Professor  of Computer Science
>>>> UMASS-Boston
>>>> 100 Morrissey Blvd
>>>> Boston, MA 02125-3390
>>>>
>>>> IT Staff
>>>> Filtered Push Project
>>>> Harvard University Herbaria
>>>> Harvard University
>>>>
>>>> email: morris.bob@gmail.com
>>>> web: http://efg.cs.umb.edu/
>>>> web: http://wiki.filteredpush.org
>>>> http://www.cs.umb.edu/~ram
>>>> ===
>>>> The content of this communication is made entirely on my
>>>> own behalf and in no way should be deemed to express
>>>> official positions of The University of Massachusetts at Boston or
>>>> Harvard University.
>>>>
>>
>>
>>
>> --
>> Robert A. Morris
>>
>> Emeritus Professor  of Computer Science
>> UMASS-Boston
>> 100 Morrissey Blvd
>> Boston, MA 02125-3390
>>
>> IT Staff
>> Filtered Push Project
>> Harvard University Herbaria
>> Harvard University
>>
>> email: morris.bob@gmail.com
>> web: http://efg.cs.umb.edu/
>> web: http://wiki.filteredpush.org
>> http://www.cs.umb.edu/~ram
>> ===
>> The content of this communication is made entirely on my
>> own behalf and in no way should be deemed to express
>> official positions of The University of Massachusetts at Boston or
>> Harvard University.
>>
>
Received on Monday, 28 January 2013 20:26:33 GMT

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