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Re: Manifest(o)s, offline reading, and EPUB+WEB

From: Liam R. E. Quin <liam@w3.org>
Date: Mon, 22 Jun 2015 22:58:51 -0400
Message-ID: <1435028331.15512.40.camel@w3.org>
To: Brady Duga <duga@google.com>
Cc: Liza Daly <liza@safaribooksonline.com>, Dave Cramer <dauwhe@gmail.com>, W3C Digital Publishing IG <public-digipub-ig@w3.org>
On Mon, 2015-06-22 at 23:00 +0000, Brady Duga wrote:
> I expect it will be unlikely I can get permission to create 5 
> million google.com subdomains. I don't think this scales very well.

You actually only need to create one subdomain, e.g.
    read.google.com
Then, allow *.read.google.com to resolve to read.google.com.

Then people would use e.g. middlemarch.thomas-hardy.read.google.com
and that would match *.read.google.com, go to the right place, and 
could be passed to a database seach (say).

I'm not trying to promote this - AppCache isn't really designed for 
this use case and might or might not work well out of the box - but 
I'm also not trying to shoot it down.

>  Idon't know much about appcache - can the resources be on different 
> domains than the manifest? Not all content for a single book is 
> necessarily served from the
> same domain.

The AppCache spec wants everything on the same domain. You can point 
outside but other things won't be pre-fetched for offline use, as I 
understand it.

Liam

> 
> On Mon, Jun 22, 2015 at 3:10 PM Liam R. E. Quin <liam@w3.org> wrote:
> 
> > On Mon, 2015-06-22 at 15:14 -0400, Liza Daly wrote:
> > > Bookish (now the Overdrive web app) does still use app cache, 
> > > and gets around this problem by creating subdomains _for every 
> > > title_:
> > > 
> > > https://odcom-366d624d6b53b08a9d0a2c90b1dcea88.read.overdrive.com/
> > >  
> > > https://odcom-c2b601cb17f569fd4711e467edd142c1.read.overdrive.com/
> > > 
> > > I imagine this would be an unpopular general purpose solution.
> > 
> > Why would it be unpopular? It was certainly my first thought on 
> > how to get round the limitations of AppCache. Subdomains are cheap 
> > and can easily be turned into a low-overhead search on a Web 
> > server.
> > 
> > It does mean you have to have cooperation from your web server 
> > people, though, if only to install the search engine.
> > 
> > Invalidating the entire cache for a book might be a pain, though, 
> > if the book is, say, a gigabyte in total size.
> > 
> > This also maybe provides a mechanism to link between books.
> > 
> > Liam
> > 
> > > 
> > > Liza
> > > 
> > > 
> > > On Mon, Jun 22, 2015 at 2:54 PM, Dave Cramer <dauwhe@gmail.com> 
> > > wrote:
> > > 
> > > > We've recently spent a lot of time discussing how to make a 
> > > > book [1] readable both offline and online. As usual, this is 
> > > > an issue that has come
> > > > up in the larger web world. and there is a solution already
> > > > supported by every major browser. I'm speaking of AppCache 
> > > > [2], of course.
> > > > 
> > > > At first glance, AppCache seems well-suited for books. An
> > > > application manifest file (text-only) lists the resources used 
> > > > by the book, including
> > > > CSS, images, scripts, fonts, etc.:
> > > > 
> > > > CACHE MANIFEST
> > > > #v3 2015-06-05
> > > > css/mobydick.css
> > > > metadata.json
> > > > manifest.json
> > > > title-page.html
> > > > copyright.html
> > > > introduction.html
> > > > epigraph.html
> > > > c001.html
> > > > c002.html
> > > > 
> > > > 
> > > > When you first visit a page, the files listed in the manifest 
> > > > are downloaded. The next time you visit the page, you'll get 
> > > > the
> > > > cached version. This is a problem for the regular web, but 
> > > > could be an advantage
> > > > for us. If you change the manifest file on the server, you 
> > > > will trigger an
> > > > update of the cache.
> > > > 
> > > > So my question is, why does everyone hate [3,sorry about the
> > > > language] this? The cache manifest itself would be helpful for 
> > > > EPUB+WEB, as it gives
> > > > us the list of files everyone seems to want, but far simpler 
> > > > than EPUB's <manifest> element.
> > > > 
> > > > * * *
> > > > 
> > > > To be fair, the word "manifest" is probably less overloaded 
> > > > than the word
> > > > "template." Nevertheless, the "Manifest for a web application" 
> > > > specification [4] appears to be unrelated to the application
> > > > manifest used
> > > > by AppCache. Manifests for web applications are JSON files 
> > > > that provide metadata for a web app. They could provide a 
> > > > location and syntax for book
> > > > metadata, and identify a starting point for the book:
> > > > 
> > > > {
> > > >   "name": "Moby-Dick",
> > > >   "short_name": "Moby-Dick",
> > > >   "icons": [{
> > > >         "src": "icons/moby-dick-icon.webp",
> > > >         "sizes": "64x64",
> > > >         "type": "image/webp"
> > > >       }],
> > > >   "start_url": "title-page.html",
> > > >   "display": "minimal-ui",
> > > > }
> > > > 
> > > > Together, these two manifests seem to meet several of 
> > > > EPUB+WEB's requirements. I'm interested in further exploring 
> > > > these ideas to see if they can be adopted or modified to meet 
> > > > our needs.
> > > > 
> > > > Dave
> > > > 
> > > > 
> > > > [1] Feel free to think "publication" every time I write "book" 
> > > > :) [2] https://html.spec.whatwg.org/multipage/browsers.html#
> > > > offline [3]  
> > > >  http://alistapart.com/article/application-cache-is-a-douchebag
> > > > [4] https://w3c.github.io/manifest/
> > > > 
> > 
> > 
Received on Tuesday, 23 June 2015 02:58:56 UTC

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