Re: [dpub identifiers] Please review updated Identifiers TF wiki

> On 23 Mar 2015, at 15:13 , Bill Kasdorf <bkasdorf@apexcovantage.com> wrote:
> 
> Thanks for moving us yet another step forward, Ivan.
> 
> Okay if I add this to the wiki?

Of course!

> I'd like to create a section, after the background section, with this content, slightly edited to make it a bit less e-mail-like.
> 
> May I go ahead and do that? Or do you want to do that?

Go ahead, I am at another meeting

Ivan

> 
> --Bill
> 
> -----Original Message-----
> From: Ivan Herman [mailto:ivan@w3.org]
> Sent: Monday, March 23, 2015 5:39 AM
> To: Bill Kasdorf
> Cc: W3C Digital Publishing IG
> Subject: Re: [dpub identifiers] Please review updated Identifiers TF wiki
> 
> Bill,
> 
> I think we have to separate two categories here:
> 
> - Purely media type specific fragments (that includes xpointer, the media fragments as mentioned by Thierry, xpath, svgview, etc)
> - Package level fragments like CFI and or the Packaging Fragments (let me refer to this as PFrag for now)
> 
> In an EPUB-WEB approach we should _not_ deal with the first category at all. Those are specified by other groups, registered by IETF, etc; the DPUB community should be a user of those just as they are users of the specific media. In future, the variety of media that can be added to a portable document will just increase and will be open ended; we should be 'clients' of that evolution.
> 
> CFI and PFrag have a different concern: the question is how to find a specific document *within* a package and then, within that document, a finer way of identifying an anchor.
> 
> I think what we should specify, as a set of requirement, is what an EPUB-WEB Fragment (say EWFrag) has to fulfill. Here is a tentative list, based on CFI and PFrag:
> 
> 1. EWFrag should have a clear way of identifying a document *within* the media 2. EWFrag should have a way to follow "paths" of references through several 'hops'
> 3. EWFrag should have a way to reuse externally defined fragment id specifications for specific media types 4. EWFrag should have clear (and simple) conceptual equivalents to URI-s with fragment ID-s when the document is directly accessed on the Web 5. EWFrag should be based, as far as possible, on technologies widely deployed on the Web (and hence in Web browsers)
> 
> For CFI:
> 
> - (1) is fulfilled (for EPUB) starting from the package file
> - (2) is fulfilled through the usage of the '!' character, though the definition seems to rely on XHMTL and SVG elements only, ie, is not really extensible
> - (3) is not fulfilled, as far as I can see; instead, it uses its own identification down to the character level in a document
> - (4) is not fulfilled, it uses its own identification
> - (5) is fulfilled today but may not work tomorrow: it is deeply rooted in XML both for the package file and the target documents; if some packages are defined in other formats (eg, JSON) then this may break down; I am not even sure it would work with HTML5 (does the '/' approach, making this differentiation between elements and text children work the same way?)
> 
> For PFrag
> 
> - (1) is fulfilled, using the list of headers within the package
> - (2) is not fulfilled, it can only go one step (from the package down to a document within the package)
> - (3) is fulfilled; in fact PFrag is concerned _only_ by the identification of a document within the package and is oblivious to the rest
> - (4) is sort of fulfilled (per documentation), but is a bit convoluted
> - (5) is fulfilled; relies on, essentially, HTTP headers, which is part of the basics on the Web
> 
> There may be other requirements (Human readability? Ease of generation?) and some of the requirements above are not really important (eg, I am not sure about the importance of (2)). But I believe this is the kind of requirements that we should really formulate.
> 
> 
> Cheers
> 
> Ivan
> 
> 
> 
> 
> 
> Bill Kasdorf wrote:
>> Thanks to Tzviya, we have some substantive content for review on the Identifiers TF wiki at [1].
>> 
>> This initial draft of background information gives brief descriptions, links, discussion, and examples of three possible options for consideration as the basis for our initial work on a Fragment Identifier:
>> --EPUB CFI
>> --W3C Packaging for the Web Fragment Identifiers --The Open
>> Annotations Fragment Selector
>> 
>> In addition, there's a placeholder for XPath, and we need to collect suggestions for other relevant specs or technologies to take into account, e.g. XPointer.
>> 
>> Please take a look at this before the Monday IG call and suggest any others we should add. Feel free to add a placeholder (ideally with a link) if you aren't prepared to add the prose.
>> 
>> And although we now have a good list of participants in this TF, please add your name if you'd like to participate as well. > We will discuss next steps on the call Monday, which will probably involve a TF conference call later this week if we can > find a time that works for everybody.
>> 
>> --Bill K
>> 
>> [1] https://www.w3.org/dpub/IG/wiki/Task_Forces/identifiers#Background
> 
> 
> ----
> Ivan Herman, W3C
> Digital Publishing Activity Lead
> Home: http://www.w3.org/People/Ivan/
> mobile: +31-641044153
> ORCID ID: http://orcid.org/0000-0003-0782-2704
> 
> 
> 
> 
> 


----
Ivan Herman, W3C
Digital Publishing Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
ORCID ID: http://orcid.org/0000-0003-0782-2704