Re: Explaining the benefits of http-range14 (was Re: [HTTP-range-14] Hyperthing: Semantic Web URI Validator (303, 301, 302, 307 and hash URIs) )

On 21/10/2011 12:52, Leigh Dodds wrote:
> Hi,
>
> On 21 October 2011 08:47, Dave Reynolds<dave.e.reynolds@gmail.com>  wrote:
>> ...
>>> On 20 October 2011 10:34, Dave Reynolds<dave.e.reynolds@gmail.com>    wrote:
>>>>
>>>> ...
>>>> If you have two resources and later on it turns out you only needed one,
>>>> no big deal just declare their equivalence. If you have one resource
>>>> where later on it turns out you needed two then you are stuffed.
>>>
>>> Ed referred to "refactoring". So I'm curious about refactoring from a
>>> single URI to two. Are developers necessarily stuffed, if they start
>>> with one and later need two?
>>>
>>> For example, what if I later changed the way I'm serving data to add a
>>> Content-Location header (something that Ian has raised in the past,
>>> and Michael has mentioned again recently) which points to the source
>>> of the data being returned.
>>>
>>> Within the returned data I can include statements about the document
>>> at that URI referred to in the Content-Location header.
>>>
>>> Doesn't that kind of refactoring help?
>>
>> Helps yes, but I don't think it solves everything.
>>
>> Suppose you have been using http://example.com/lovelypictureofm31 to denote
>> M31. Some data consumers use your URI to link their data on M31 to it. Some
>> other consumers started linking to it in HTML as an IR (because they like
>> the picture and the accompanying information, even though they don't care
>> about the RDF). Now you have two groups of users treating the URI in
>> different ways. This probably doesn't matter right now but if you decide
>> later on you need to separate them then you can't introduce a new URI
>> (whether via 303 or content-location header) without breaking one or other
>> use. Not the end of the world but it's not a refactoring if the test cases
>> break :)
>>
>> Does that make sense?
>
> No, I'm still not clear.
>
> If I retain the original URI as the identifier for the galaxy and add
> either a redirect or a Content-Location, then I don't see how I break
> those linking their data to it as their statements are still made
> about the original URI.
>
> But I don't see how I'm breaking people linking to it as if it were an
> IR. That group of people are using my resource ambiguously in the
> first place. Their links will also still resolve to the same content.

Ah OK. So you introduce a new, different IR, but preserve the conneg so 
that old HTML pages links to the picture still resolve. Yes you are 
right, I think that does work.

Dave

Received on Friday, 21 October 2011 16:18:57 UTC