Re: [DPUB][Locators]Cancellation and Next Steps

> On 21 Jan 2016, at 07:28, Ivan Herman <ivan@w3.org> wrote:
> 
> I think that is where HTTP content negotiation should come in to the picture in my view.
> (snip)
> The only thing this mechanism requires is to have a distinct media type assigned to a PWP (akin to the media type for EPUB) and, probably, to the manifest. If that is there, a client may express the media types it accepts, and even the relative priority of what format it prefers (if the client has several)
> 
> This allows for a setup where there is *no* packaged form around. And content negotiation is a mechanism implemented by all servers and clients these days, so we should just use it…

I'm not convinced by the content negotiation approach. The format to get (expanded vs. packaged) may depend on the user's intent (e.g. whether she wants to start reading the book or download it to share on a USB key); the decision is not necessarily under the responsibility of client software.
I believe it would be easier if the two formats were represented by two different URLs, which has the benefit of working in run-of-the-mill browsers.

> I think we agree that whatever is returned, it should give *an access* (in the conceptual sense) to a manifest (and we would not have to go into the syntax of the manifest here).

Yes, possibly with some level of indirection.

> The return may be
> 
> - The full actual data if there is a packaged form;

OK.

> the HTTP return header MAY (SHOULD?) also return a link to a manifest

Are you thinking of using a standard HTTP header or defining a custom one?

> but the package MUST contain a manifest in any case (we have to decide which of the manifest have priority).

If the package format allows a client to easily retrieve the manifest, this is probably enough. Why use an HTTP header in addition?
I'd suggest that making the manifest easily and deterministically retrievable from the package becomes a requirement.

> - The manifest itself, e.g., in JSON format if that is indeed the syntax we adopt, or an HTML file that includes the manifest, or an HTML file that links to the manifest

yes, for the unpackaged state.

Romain.


> 
> Ivan
> 
> 
> 
>> 
>> On the manifest question, I think that the discussion taking place for EPUB about a JSON-based manifest may be useful here as there is definitely overlap in the organization and structure of that material that we would also want here.  And if we could potentially align these two efforts to a single manifest format, then it would make it trivial for implementations to author and provide it (no transcoding required).   But yes, there would need to be more stuff from PWP’s perspective (such as the optional mapping for external resources)
>> 
>> 
>> Leonard
>> 
>> From: Bill Kasdorf <bkasdorf@apexcovantage.com <mailto:bkasdorf@apexcovantage.com>>
>> Date: Wednesday, January 20, 2016 at 9:19 AM
>> To: "public-digipub-ig@w3.org <mailto:public-digipub-ig@w3.org>" <public-digipub-ig@w3.org <mailto:public-digipub-ig@w3.org>>
>> Subject: [DPUB][Locators]Cancellation and Next Steps
>> Resent-From: <public-digipub-ig@w3.org <mailto:public-digipub-ig@w3.org>>
>> Resent-Date: Wednesday, January 20, 2016 at 9:20 AM
>> 
>> Hi, folks—
>> 
>> Today's Locators Task Force meeting is cancelled, but our Task is not. ;-)
>> 
>> It has been suggested by several people that focusing on the actual structure of the locator, and getting a strawman proposal written down, is what we need to do now.
>> 
>> There has been some interesting discussion on the list:
>> 
>> https://lists.w3.org/Archives/Public/public-digipub-ig/2015Dec/0163.html <https://lists.w3.org/Archives/Public/public-digipub-ig/2015Dec/0163.html> (from Daniel Weck)
>> https://lists.w3.org/Archives/Public/public-digipub-ig/2016Jan/0095.html <https://lists.w3.org/Archives/Public/public-digipub-ig/2016Jan/0095.html>  (from Ángel González)
>> 
>> Ivan suggests that we need to write down:
>> 
>> - what should a GET return for a locator (something which is or either refers to a manifest in the abstract sense)
>> - what should a manifest, conceptually, include. At this moment, I see
>>                 - an *identifier*
>>                 - a mapping from absolute URL-s to relative URL-s (where relative means relative to the PWP instance URL)
>>                 - a mapping from relative URL-s to absolute URL-s
>> 
>> Could somebody volunteer to draft a strawman proposal that we can use for the basis of discussion going forward?
>> 
>> --Bill
>> 
>> Bill Kasdorf
>> Vice President, Apex Content Solutions
>> Apex CoVantage
>> W: +1 734-904-6252
>> M: +1 734-904-6252
>> @BillKasdorf <http://twitter.com/#!/BillKasdorf>
>> bkasdorf@apexcovantage.com <x-msg://17/bkasdorf@apexcovantage.com>
>> http://isni.org/isni/0000000116490786 <http://isni.org/isni/0000000116490786>
>> https://orcid.org/0000-0001-7002-4786 <https://orcid.org/0000-0001-7002-4786?lang=en>
>> www.apexcovantage.com <http://www.apexcovantage.com/>
>> 
>> <image001.jpg>
>> 
>> <image001.jpg>
> 
> 
> ----
> Ivan Herman, W3C
> Digital Publishing Lead
> Home: http://www.w3.org/People/Ivan/ <http://www.w3.org/People/Ivan/>
> mobile: +31-641044153
> ORCID ID: http://orcid.org/0000-0003-0782-2704 <http://orcid.org/0000-0003-0782-2704>
> 
> 
> 
>