(Packaged) Web Publications (PWP)

These Slides are Available on the Web

See:
http://w3c.github.io/dpub/2016/Beijing/index.html

(Slides are in HTML)

EPUB 3 is a very mature specification

• Widely used format for digital publication
• A truly portable and non-proprietary format
• The standard format for digital books…
• …but can be also be used for magazines, journal articles, documentation, etc.

Books with illustrations

Art books

Mangas

Technical books

Books with different character sets and writing directions

…journals or magazines (articles)

…official reports of all kinds

In fact, just about anything!

Well, at least one of the secrets…

• EPUB is based on Web Technologies like HTML, CSS, SVG, JS, etc.
  • collectively referred to as “Open Web Platform” (OWP)
• I.e., no separate rendering, formatting, etc., specification had to be defined
• Instead, EPUB relies on specifications defined by W3C and deployed in browsers

A good example

• The image on the right is displayed through that translucent “screen”
• This is not done through some separate image processing step
• Instead, it is based on some complex CSS features (implemented in browsers but also in EPUB readers)

Are we all done?
I.e., are OWP and EPUB a perfect match?

There are two major areas that need work:

1. bring OWP and Digital Publishing closer
2. bring the Web and Digital Publishing closer

Missing OWP features

• Some features, needed by publishing, are missing from OWP; examples:
  • pagination, page controls for headings, page numbers
  • graphics transition effects (needed in, e.g., mangas, cartoons, children books)
  • taking into account the typesetting requirements of different cultures (French, Russian, Arabic, Chinese, Japanese,…)
• Bring extra Web facilities, libraries, services, etc., closer to publishing
• W3C has a Digital Publishing Interest Group to look into these issues and cooperate with the relevant W3C groups

What is, in fact, a (digital) book?

• It is a mean to transmit ideas to readers in various formats
• It is independent of format: the same “book” should be available in different format and media
  • printed book, digital books, Web page(s)…
• Today, a Digital Book is different than a Web page (conceptually and practically)

What we get today…

• One can download an EPUB (and other formats) from a Web site…

What we get today…

• …get a very traditional text to read…

What we get today…

• …but access a different (and possibly nicer) Web page online…
• This should not be the case!

“This should not be the case!”
what does this mean?

For example: book in a browser

• On a desktop I may want to read a book just like a Web page:
  • easily follow a link “out” of the book
  • create bookmarks to “within” a page in a book
  • use useful plugins and tools that my browser may have
  • create annotations
  • sometimes I may need the computing power of my desk-top for, e.g., powerful text analysis

For example: book in a browser

• But, at other times, I may also want to use a small dedicated reader device to read the book on the beach…
• All these on the same book (not conversions from one format to the other)!

For example: I may not be online…

• I may find an article on the Web that I want to review, annotate, etc., while commuting home on a train
• I want the results of the annotations to be back online, when I am back on the Internet

For example: scholarly publishing

• Paper may be published on-line, but people may want to download it for offline use
• The format of the paper should be adaptable to reading environment
  • no two column, fixed layout file that cannot be handled on an my tablet…
• The “paper” may also contain video, audio, data, programs…
  • scholarly publishing is not text only any more!

Need for the concept of a “publication” of many resources

• A publication may consist of many resources (text, images, videos, etc)
• On the Web, these are linked together, but they keep their complete “independence”
• For publishing the abstract “work” should be a single, conceptual unit on the Web: a Web Publication (WP)

What does that mean technically?

• The current Web builds on the notion of a single resource:
  • HTML source, metadata, CSS style sheet, etc.
  • each has its own URL
• Rendering is based on the interoperation of many such resources

What does that mean technically?

• A WP is collection of Web resources considered as one unit
  • this means there is a unique Web address for the collection (as opposed to a single constituent)
  • the same WP can be offline or online with the same address
• WP-s are part of the Web!

Why do we need the WP concept?

• The whole book should be archived in a national library
• The publication has to be checked for integrity as a whole (e.g., in a legal publication)
• Sharing a publication with a friend requires the concept of the publication as a whole
• Publishing and library business models are based on the concept of “works”

Why do we need the WP concept?

• Value counters (counters, section numbering, footnotes, endnotes, etc.) should be consistent across the publication
• Any search, text analysis, etc., facility for a book should have access to the full publication
• User preferences should apply to the “work” rather than to a single Web page

(Some) technical challenges

• How to ensure a unique identification of a WP?
• How to represent, programatically, the concept of a WP?
• How to assign metadata, additional information, etc., to a WP (rather than just a Web page)?
• How to control user interface preferences for a full WP?
• How to ensure security for the full publication (even if it is copied)?

Envisioned architecture:
online

Envisioned architecture:
offline

Advances in modern browsers: Web and Service Workers

• Web Worker: a truly parallel thread within the browser
• A Service Worker is a special type of Web Worker, with additional features:
  • it is a programmable network proxy: the renderer’s network calls are caught and the request/answer can be modified on-the-fly behind the scenes
  • it has an interface to handle a local cache for networked data
  • it will stay alive even if the user moves away from the main page, and can be accessed later if he/she returns to it

Service Workers are coming…

• Browser engines are heading towards Service Workers today
  • a major technology to reconcile Mobile Applications and Web Developments
• I.e, Web Publications build on an evolution that is already happening

Manifests

• A WP needs a number of extra information
  • different type of metadata (author, title, publisher, etc.)
  • list of resources within a WP
  • table of content information, i.e., default reading order
  • unique identifier (ISBN, DOI, etc.)
  • references to more complex metadata (e.g., ONIX data)
• The traditional term is “manifest” for such information
• A detailed manifest must be specified for WP-s

Work on “Web App Manifests”

• Work is happening at W3C
  • used for Web Applications
  • contains lots of display-oriented data, and some metadata
  • describes a precise way of fetching manifests and content in a secure context
  • contains data for an application based on Service Workers
• A WP manifest can build on this evolution as well!

Packaged Web Publications (PWP)

• For a large number of use cases Web Publications (essentially, online/offline reading) is all they really need
  • e.g., scholarly journals, online magazines, brochures
• But a number of use cases rely on an extra step: to “pack” the content of a WP into a single file
  • archival, library distributions,…
  • extension of the current business model of trade publishers (built on EPUB)

A layer “on top” of WP-s

• Packaging means collecting all the content of a WP into a single file
• Some additional issues to be handled:
  • special entries to the manifest
  • archival format(s)
  • etc.
• A specific “profile” for WP may have to be defined for a PWP

Structure of an EPUB3 file

A Packaging of a Web Publication

• A Packaged Web Publication may have a very similar structure
• But moving to the Web would probably require to rethink the format of the administrative files
  • e.g., manifest would be in JSON
  • structure of metadata may different
  • etc.

PWP packaging structure

A PWP Processor

• PWP-s may be handled by dedicated applications
• But the concept of a WP processor can be extended to a PWP processor, unpacking content on the fly
  • security considerations must be handled, though

A PWP Processor

PWP vs. EPUB3.1

• PWP does not replace EPUB 3 today
• It is, instead, part of a future evolution, or a vision, for the years to come

Most things are the same!

• Important to note that the content of a PWP and EPUB 3 are identical
  • usage of HTML, CSS, SVG, etc.
• The main change is the “administrative” aspect of the publication (locators, manifest, etc)

Advantage for the publishers‘ community

• The main interest of publishers is to produce, edit, curate, etc., content
• Publishers would have an easier access to a large audience
• Publishers have invested heavily into technology developments, but the Web developers’ community can complement that with a wider reach and perspective

Advantage for the publishers‘ community

• Working closely with Web developers avoids re-inventing wheels
  • e.g., API-s to access system resources or utilities, like index database, battery status API, real-time communication, geolocation,…
• Aligning more on OWP means that specialized readers or Web sites, software, services, etc, can rely on it

Advantage for the Web community

• Publishers have experience in:
  • ergonomics, typography, aesthetics…
  • publishing long texts, with the right readability and structure
• Workflow for producing complex content
• In some sense, a new type of content comes to the fore

Some references

Latest PWP Use Cases and Requirements draft:

https://w3c.github.io/dpub-pwp-ucr/

Latest PWP Editors’ draft:

https://w3c.github.io/dpub-pwp/

PWP Issue list:

https://github.com/w3c/dpub-pwp/issues

Thank you for your attention!

This presentation:

http://w3c.github.io/dpub/2016/Beijing/index.html

My contact:

ivan@w3.org