<Glazblog/>

Long looooong ago, I wrote a deep review of the XHTML 2.0 spec that was one of the elements that led to the resuming of the HTML activity at the W3C and the final dismissal of XHTML 2.0. 

Long ago, I started a similar effort on EPUB that led to Dave Cramer's EPUB Zero. It's time (fr-FR) to draw some conclusions.

This document is maintained on GitHub and accepting contributions.

Daniel Glazman

OCF

1. EPUB publications are not "just a zip". They are zips with special constraints. I question the "mimetype file in first uncompressed position" constraint since I think the vast majority of reading systems don't care (and can't care) because most of the people creating EPUB at least partially by hand don't know/care. The three last contraints (zip container fields) on the ZIP package described in section 4.2 of the spec are usually not implemented by Reading Systems.
2. the container element of the META-INF/container.xml file has a version attribute that is always "1.0", whatever the EPUB version. That forces editors, filters and reading systems to dive into the default rendition to know the EPUB version and that's clearly one useless expensive step too much.
3. having multiple renditions per publication reminds me of MIME multipart/alternative. When Borenstein and Freed added it to the draft of RFC 1341 some 25 years ago, Mail User Agents developers (yours truly counted) envisioned and experimented far more than alternatives between text/html and text/plain only. I am under the impression multiple renditions start from the same good will but fail to meet the goals for various reasons:
   1. each additional rendition drastically increases the size of the publication...
   2. most authoring systems, filters and converters on the market don't deal very well with multiple renditions
   3. EPUB 2 defined the default rendition as the first rendition with a application/oebps-package+xml  mimetype while the EPUB 3 family of specs defines it as the first rendition in the container
   4. while a MIME-compliant Mail User Agent will let you compose a message in text/html and output for you the multipart/alternative between that text/html and its text/plain serialization, each Publication rendition must be edited separately.
   5. in the case of multiple renditions, each rendition has its own metadata and it's then legitimate to think the publication needs its own metadata too. But the META-INF/metadata.xml file has always been quoted as "This version of the OCF specification does not define metadata for use in the metadata.xml file. Container-level metadata may be defined in future versions of this specification and in IDPF-defined EPUB extension specifications." by all EPUB specifications. The META-INF/metadata.xml should be dropped.
   6. encryption, rights and signatures are per-publication resources while they should be per-rendition resources.
4. the full-path attribute on rootfile elements is the only path in a publication that is relative to the publication's directory. All other URIs (for instance in href attributes) are relative to the current document instance. I think full-path should be deprecated in favor of href here, and finally superseded by href for the next major version of EPUB.
5. we don't need the mimetype attribute on rootfile elements since the prose of EPUB 3.1 says the target of a rootfile must be a Package Document, i.e. an OPF file... If EPUB 2 OCF could directly target for instance a PDF file, it's not the case any more for OCF 3.
6. absolute URIs (for instance /files/xhtml/index.html with a leading slash, cf. path-absolute construct in RFC 3986) are harmful to EPUB+Web convergence
7. if multiple renditions are dropped, the META-INF/container.xml file becomes useless and it can be dropped.
8. the prose for the META-INF/manifest.xml makes me wonder why this still exists: "does not mandate a format", "MUST NOT be used". Don't even mention it! Just say that extra unspecified files inside META-INF directory must be ignored (Cf. OCF section 3.5.1) , and possibly reserve the metadata.xml file name, period. Oh, and a ZIP is also a manifest of files...
9. I am not an expert of encryption, signatures, XML-ENC Core or XML DSIG Core, so I won't discuss encryption.xml and signatures.xml files
10. the rights.xml file still has no specified format. Strange. Cf. item 8 above.
11. Resource obfuscation is so weak and useless it's hilarious. Drop it. It is also painful in EPUB+Web convergence.
12. RNG schemas are not enough in the OCF spec. Section 3.5.2.1 about container.xml file for instance shouls have models and attribute lists for each element, similarly to the Packages spec.
13. not sure I have ever seen links and link elements in a container.xml file... (Cf. issue #374). The way these links are processed is unspecified anyway. Why are these elements normatively specified since extra elements are allowed - and explicitely ignored by spec - in the container?

Packages

1. a Package consists of one rendition only.
2. I have never understood the need for a manifest of resources inside the package, probably because my own publications don't use Media Overlays or media fallbacks.
3. fallbacks are an inner mechanism also similar to multipart/alternative for renditions. I would drop it.
4. I think the whole package should have properties identifying the required technologies for the rendition of the Package (e.g. script), and avoid these properties on a per-item basis that makes no real sense. The feature is either present in the UA for all content documents or for none.
5. the spine element represent the default reading order of the package. Basically, it's a list. We have lists in html, don't we? Why do we need a painful and complex proprietary xml format here?
6. the name of the linear attribute, that discriminates between primary and supplementary content, is extremely badly chosen. I always forget what really is linear because of that.
7. Reading Systems are free, per spec, to completely ignore the linear attribute, making it pointless from an author's point of view.
8. I have never seen the collection element used and I don't really understand why it contains link elements and not itemref elements
9. metadata fun, as always with every EPUB spec. Implementing refines in 3.0 was a bit of a hell (despite warnings to the EPUB WG...), and it's gone from 3.1, replaced by new attributes. So no forwards compatbility, no backwards compatibility. Yet another parser and serializer for EPUB-compliant user agents.
10. the old OPF guide element is now a html landmarks list, proving it's feasible to move OPF features to html
11. the Navigation Document, an html document, is mandatory... So all the logics mentioned above could be there.
12. Fixed Layout delenda est. Let's use CSS Fragmentation to make sure there's no orphaned content in the document post-pagination, and if CSS Fragmentation is not enough, make extension contributions to the CSS WG.
13. without 3.0 refines, there is absolutely nothing any more in 3.1 preventing Package's metadata to be expressed in html; in 3.0, the refines attribute was a blocker, implying an extension of the model of the meta html element or another ugly IDREF mechanism in html.
14. the prefix attribute on the package element is a good thing and should be preserved
15. the rendition-flow property is weird, its values being paginated, scrolled-continuous, scrolled-doc and auto. Where is paginated-doc, the simplest paginated mode to implement?
16. no more NCX, finally...
17. the Navigation Document is already a html document with nav elements having a special epub:type/role (see issue #941), that's easy to make it contain an equivalent to the spine or more.

Content Documents

1. let's get rid of the epub namespace, please...

Media Overlays

1. SMIL support across rendering engines is in very bad shape and the SMIL polyfill does not totally help. Drop Media Overlays for the time being and let's focus on visual content.

Alternate Style Tags

1. terrible spec... Needed because of Reading Systems' limitations but still absolutely terrible spec...
2. If we get rid of backwards compatibility, we can drop it. Submit extensions to Media Queries if needed.

On the fly conclusions

1. backwards compatibility is an enormous burden on the EPUB ecosystem
2. build a new generation of EPUB that is not backwards-compatible
3. the mimetype file is useless
4. file extension of the publication MUST be well-defined
5. one rendition only per publication and no more links/link elements
6. in that case, we don't need the container.xml file any more
7. metadata.xml and manifest.xml files removed
8. we may still need encryption.xml, signatures.xml and rights.xml inside a META-INF directory (or directly in the package's root after all) to please the industry.
9. application/oebps-package+xml mimetype is not necessary
10. the EPUB spec evolution model is/was "we must deal with all cases in the world, we move very fast and we fix the mistakes afterwards". I respectfully suggest a drastic change for a next generation: "let's start from a low-level common ground only and expand slowly but cleanly"
11. the OPF file is not needed any more. The root of the unique rendition in a package should be the html Navigation Document.
12. the metadata of the package should be inside the body element of the Navigation Document
13. the spine of the package can be a new nav element inside the body of the Navigation Document
14. intermediary summary: let's get rid of both META-INF/container.xml and the OPF file... Let's have the Navigation Document mandatorily named index.xhtml so a directory browsing of the uncompressed publication through http will render the Navigation Document.
15. let's drop the Alternate Style Tags spec for now. Submission of new Media Queries to CSS WG if needed.
16. let's drop Media Overlays spec for now.

CONCLUSION

EPUB is a monster, made to address very diverse markets and ecosystems, too many markets and ecosystems. It's weak, complex, a bit messy, disconnected from the reality of the Web it's supposed to be built upon and some claim (link in fr-FR) it's too close to real books to be disruptive and innovative.

I am then suggesting to severe backwards compatibility ties and restart almost from scratch, and entirely and purely from W3C Standards. Here's the proposed result:

1. E0 Publication

A E0 Publication is a ZIP container. Files in the ZIP must be stored as is (no compression) or use the Deflate algorithm. File and directory names must be encoded in UTF-8 and follow some restrictions (see EPUB 3.1 filename restrictions).

The file name of a E0 Publication MUST use the e0 file extension.

A E0 Publication MUST contain a Navigation Document. It MAY contain files encryption.xml, signatures.xml and rights.xml (see OCF 3.1 for more information). All these files must be placed directly inside the root of the E0 Publication.

A E0 Publication can also contain Content Documents and their resources.

Inside a E0 Publication, all internal references (links, anchors, references to replaced elements, etc) MUST be strictly relative. With respect to section 4.2 of RFC 3986, only path-noscheme and path-empty are allowed for IRIs' relative-part. External references are not restricted.

2. E0 Navigation Document

A E0 Navigation Document is a html document. Its file name MUST be index.xhtml if the document is a XML document and index.html if it it is not a XML document. A E0 Publication cannot contain both index.html and index.xhtml files.

A E0 Navigation Document contains at least one header element (for metadata) and at least two nav html elements (for spine and table of contents) in its body element.

2.1. E0 Metadata in the Navigation Document

E0 metadata are designed to be editable in any Wysiwyg html editor, and potentially rendered as regular html content by any Web browser.

E0 metadata are expressed inside a mandatory header html element inside the Navigation Document. That element must carry the "metadata" ID and the vocab attribute with value "http://www.idpf.org/2007/opf". All metadata inside that header element are then expressed using html+RDFa Lite 1.1. E0 metadata reuse EPUB 3.1 metadata and corresponding unicity rules, expressed in a different way.

Refinements of metadata are expressed through nesting of elements.

Example:

<header id="metadata"
        vocab="http://www.idpf.org/2007/opf">
  <h1>Reading Order</h1>
  <ul>
    <li>Author:
        <span property="dc:creator">glazou
         (<span property="file-as">Glazman, Daniel</span>)</span></li>
    <li>Title:
        <span property="dc:title">E0 Publications</span></li>
  </ul>
</header>

The mandatory title element of the Navigation Document, contained in its head element, should have the same text contents than the first "dc:title" metadata inside that header element.

2.2. E0 Spine

The spine of a E0 Publication is expressed in its Navigation Document as a new nav element holding the "spine" ID. The spine nav element is mandatory.

See EPUB 3.1 Navigation Document.

2.3. E0 Table of Contents

The Table of Contents of a E0 Publication is expressed in its Navigation Document as a nav element carrying the "toc" ID. The Table of Contents nav element is mandatory.

See EPUB 3.1 Navigation Document.

2.4. E0 Landmarks

The Landmarks of a E0 Publication is expressed in its Navigation Document as a nav element carrying the "landmarks" ID. The Landmarks nav element is optional.

See EPUB 3.1 Navigation Document.

2.5. Other nav elements

The Navigation Document may include one or more nav elements. These additional nav elements should have an role attribute to provide a machine-readable semantic, and must have a human-readable heading as their first child.

IDs "metadata", "spine" , 'landmarks" and "toc" are reserved in the Navigation Document and must not be used by these extra nav elements.

2.6. Example of a Navigation Document

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta content="text/html; charset=UTF-8" http-equiv="content-type">
    <title>Moby-Dick</title>
  </head>
  <body>
    <header id="metadata"
            vocab="http://www.idpf.org/2007/opf">
      <ul>
        <li>Author:
          <span property="dc:creator">Herman Melville
            (<span property="file-as">Melville Herman</span>)</span></li>
        <li>Title:
            <span property="dc:title">Moby-Dick</span></li>
	<li>Identifier:
	    <span property="dc:identifier">glazou.e0.samples.moby-dick</span></li>
	<li>Language:
	    <span property="dc:language">en-US</span></li>
	<li>Last modification:
	    <span property="dcterms:modified">2017-01-17T11:16:41Z</span></li>
	<li>Publisher:
	    <span property="dc:publisher">Harper & Brothers, Publishers</span></li>
	<li>Contributor:
	    <span property="dc:contributor">Daniel Glazman</span></li>
      </ul>
    </header>

    <nav id="spine">
      <h1>Default reading order</h1>
      <ul>
	<li><a href="cover.html">Cover</a></li>
	<li><a href="titlepage.html">Title</a></li>
	<li><a href="toc-short.html">Brief Table of Contents</a></li>
	...
      </ul>
    </nav>

    <nav id="toc" role="doc-toc">
      <h1>Table of Contents</h1>
      <ol>
	<li><a href="titlepage.html">Moby-Dick</a></li>
	<li><a href="preface_001.html">Original Transcriber’s Notes:</a></li>
	<li><a href="introduction_001.html">ETYMOLOGY.</a></li>
	...
      </ol>
    </nav>
  </body>
</html>

3. Directories

A E0 Publication may contain any number of directories and nested directories.

4. E0 Content Documents

E0 Content Documents are referenced from the Navigation Document. E0 Content Documents are html documents.

E0 Content Documents should contain <link rel="prev"...> and <link rel="next"...> elements in their head element conformant to the reading order of the spine present in the Navigation Document. Content Documents not present in that spine don't need such elements.

The epub:type attribute is superseded by the role attribute and must not be used.

5. E0 Resources

E0 Publications can contain any number of extra resources (CSS stylesheets, images, videos, etc.) referenced from either the Navigation Document or Content Documents.

I feel the need to add context to the contents of my previous article about the architecture of the royal Castle of Chambord, probably one of the most beautiful castles in France. It's commonly accepted that the castle was built based on a grid layout, and the french version of Wikipedia has some details about that design:

Plan illustrant le concept initial du Château - Monsieur W, CC0

Unfortunately, this theory is really partial since it does not explain many, too many choices:

• on the grid above, the dungeons seems carefully aligned with the grid, and the center of the towers should then be perfectly aligned with the sides of the main body of the castle. It is very clear from the map and de visu that it's not the case. The main body of the castle eats lets than a fourth of each tower and, again, it's extremely visible if you pay a real-life visit to the castle: the two angles between a tower's walls and the main body are less than 90°.
• this does not explain how the size of the main body of the castle was chosen
• the grid above works only if the center column and row are slightly larger than the other ones
• it does not explain the obvious ratios between the castle itself and its enclosure
• with my Standards freak's eye, there are too many things left unspecified

So I think the way the castle was designed is different and I think the WHOLE basis for it is the diameter of the towers/enclosure towers. Once that value is specified, the whole castle can be entirely derived from very basic operations that are so simple a rule and a compass are enough to draw the whole thing.

Before diving into the architecture of the main body of the castle itself, we must see that the enclosure of the castle (without towers) is very precisely a scale(3, 2) of the main body of the castle (without towers). So if we can show that the main body of the castle itself is determined solely from the diameter of the towers, it will imply the whole architecture, from enclosure to main body will rely on a single length only !

Let's do that here...

If you take the result of that experiment and overlay it over the map of the main body of the castle, it's a perfect and precise match. Since the enclosure is trivial to determine from here, the whole plan relies, as expected, on a single value : the diameter of the towers.

Chambord is a mathematical construct, with the computation of a square enclosing a pavement of 5 circles, a placement of 4 of the same circles around the square and then a trivial scaling of that construct to build the enclosure. I'm pretty sure we could also find a scale ratio between the height of the enclosure and the height of the main body of the castle.

All in all, the grid system quoted above seems to me approximative, and most probably mistaken.

There are - there were - two BlueGriffons: the Web Editor (aka BlueGriffon) and the EPUB2/EPUB3 editor (aka BlueGriffon EPUB Edition). With forthcoming v2.2, these are going to merge into a single product so they will never be out of sync again. Technically, the merge is already achieved and the next days will be spent on testing/ironing. Licenses for each product will work with that v2.2. BlueGriffon licenses will, as before, enable the commercial features of the product while licenses of the EPUB Edition will enable the commercial features AND EPUB2/EPUB3 editing. We'll also add an upgrade at special cost from the former to the latter. Stay tuned!

I have just added support for WAI-ARIA 1.1 and DPUB-ARIA 1.0 to the trunk of BlueGriffon. The next public version (2.2) will include those changes. In the meantime, a OS X trial version is available from here. You'll find the changes implemented inside the new panel Panels > ARIA.

Le PPF (paysage politique français) est bien secoué, dites donc :

• un Président out (Hollande)
• un ex-Président out (Sarkozy)
• un ex-Premier Ministre out (Juppé)
• un autre ex-Premier Ministre out (Raffarin, qui n'est plus dans l'organigramme de LR)
• plein d'ex-Ministres juppéistes sur le carreau
• plein de Ministres hollandistes sur le carreau en mai prochain

Je m'amuse, mais je m'amuse !

I think we can now safely say Opera, the browser maker, is no more. My opinions about the acquisition of the browser by a chinese trust were recently confirmed and people are let go or fleeing en masse. Rest in Peace Opera, you brought good, very good things to the Web and we'll miss you.

In fact, I'd love to see two things appear:

• Vivaldi is of course the new Opera, it was clear from day 1. Even the name was chosen for that. The transformation will be completed the day Vivaldi joins W3C and sends representatives to the Standardization tables.
• Vivaldi and Brave should join forces, in my humble opinion.

Cash Investigation vient d'interviewer le Vice-Amiral Coustillière. Je passe sur le fait qu'il parle de « blackdoor » pour revenir sur ses propos expliquant son choix. Ce type est totalement à côté de la plaque et a démontré en vingt secondes son incompétence totale en la matière. Il a raconté n'importe quoi et ne mesure absolument pas la portée de ses propos, de ses choix, de ses faiblesses mais surtout des faiblesses qu'il vient d'introduire dans la Défense Nationale française. Monsieur Le Drian, vous êtes là ?

J'ai toujours dit que la standardisation au W3C, c'est de l'hémoglobine sur les murs dans une ambiance feutrée. Je ne changerai pas un iota à cette affirmation. Mais le W3C c'est aussi l'histoire d'une industrie dès ses premières heures et des amitiés franches construites dans l'explosion d'une nouvelle ère. J'ai passé ce soir, en marge du Technical Plenary Meeting du W3C à Lisbonne, un dîne inoubliable avec mes vieux potes Yves et Olivier que je connais et apprécie depuis ohlala tellement longtemps. Un moment délicieux, sympa et drôle autour d'un repas fabuleux dans une gargote lisboète de rêve. Des éclats de rire, des confidences, une super-soirée bref un vrai moment de bonheur. Merci à eux pour cette géniale soirée et à Olivier pour l'adresse, en tous points extra. Je re-signe quand vous voulez, les gars, et c'est un honneur de vous avoir comme potes

On vient de me demander sur twitter ce que je pensais de l'initiative ministérielle d'introduire la programmation dès l'école primaire. Je vais vous expliquer ci-dessous pourquoi je suis assez mal placé pour répondre, malgré toutes les bonnes raisons que vous imaginez que je pourrais avoir :

• quand j'ai moi-même commencé à coder, pas un seul autre élève de mon collège parisien n'avait jamais même vu un ordinateur. Je dis bien vu. Aujourd'hui, les enfants sont familiarisés avec les tablettes, les consoles et souvent les ordinateurs depuis leur plus jeune âge, et cela change tout.
• j'étais très en avance et donc l'âge auquel j'ai moi-même commencé la programmation ne peut être significatif
• je suis tombé dedans comme Obelix dans la marmite de potion magique, cela a été une vocation dès la première minute. Je ne peux donc être représentatif et mon opinion est forcément fortement biaisée.

Ceci dit, on sait désormais que :

• même les très jeunes bébés sont capables de tout apprendre, y compris la langue des signes à six mois
• que le cerveau enfantin, de TOUS les enfants, est une éponge d'une magnitude que l'on commence seulement à soupçonner
• qu'un des frein majeurs à l'apprentissage des mathématiques est l'absence de construction logique

En théorie, je serais donc plutôt favorable à la mesure. MAIS il ne faut pas oublier le reste :

• une proportion tout simplement hallucinante d'élèves sortent du primaire avec un niveau de français et de calcul TRÈS insuffisant pour le collège. Apprendre à programmer, c'est la cerise sur le gâteau. Or le gâteau est d'une qualité de plus en plus mauvaise et je crois qu'il faudrait focaliser sur la qualité du gâteau avant de penser à fignoler le glaçage.
• un élève totalement infoutu de calculer de tête des choses simples aura du mal à visualiser une réflexion algorithmique même triviale
• en plus pure théorie, je me demande bien qui va assurer ces cours de programmation. Les CAPES ne font pas le plein, les profs ne sont plus formés et on leur balance des nouveautés à assurer pratiquement sans qu'ils soient mis à niveau. On compte sur qui, là ? Des informaticiens débutants payés au SMIC mais sans expérience pédagogique ? Des profs de maths qu'on n'aura pas le temps de former ?

Donc toujours en théorie, je reste favorable à la mesure. En pratique, je crois que l'École a d'autres chantiers bien plus urgents que mettre en place une nouvelle usine à gaz. L'initiation à la programmation me semblerait bien plus pertinente en classe de 4ème.