EPUB 3 Working Group Telco — Minutes

Date: 2021-04-15

See also the Agenda and the IRC Log


Present: Masakazu Kitahara, Toshiaki Koike, Dave Cramer, Matthew Chan, Wendy Reid, Shinya Takami (高見真也), Brady Duga, Marisa DeMeglio, Dan Lazin

Regrets: Ben Schroeter


Chair: Dave Cramer

Scribe(s): Matthew Chan


1. Summary of FXL and Virtual Locators calls

Wendy Reid: we had calls for both TF this week
… both moving forward
… FXL TF has divided up the work we talked about last meeting
… updating Daisy KB
… best practices documentation (probably end up as WG note)
… and modern HTML and CSS standards in epubs
… Locators had a really productive calls
… broke down the use-cases
… we will review CFI to see what we can learn

Dan Lazin: CFI does what we need, but it is not that friendly
… so we want to think about whether we can have something more user friendly

Wendy Reid: we talked about whether there was anything we could do to make our solution as “webby” as possible

Dave Cramer: there’s some API that’s supposed to solve the problem of how to locate something within a webpage

Wendy Reid: the findtext API?

Brady Duga: we release Chrome extension for making link to arbitrary location on a page (basically by finding some text)

Dave Cramer: and having indexers involved is really good

Dan Lazin: they are enthusiastic and knowledgable, one of our indexers is a current PhD candidate in the ebook area

2. language around rendition:flow

See github issue #1313.

See github pull request #1616.

Dave Cramer: See Relevant comment within the PR

Dave Cramer: I was concerned that we say RS MUST use auto as a default value, but auto means “RS, do whatever you want”
… not sure that it was testable
… but Dan thinks it is testable
… so maybe we should just undo that resolution
… if it is testable i’m fine with restoring that requirement

Brady Duga: agree. Not worth spending much time on.
… and agree with dlazin’s testing method for it

Dave Cramer: yes, we just need to see that things are consistent between having explicit auto value and “implied” auto

Proposed resolution: Merge PR 116 (Wendy Reid)

Brady Duga: +1

Dave Cramer: +1

Wendy Reid: +1

Matthew Chan: +1

Dan Lazin: +1

Masakazu Kitahara: +1

Toshiaki Koike: +1

Marisa DeMeglio: +1

Shinya Takami (高見真也): +1

Resolution #1: Merge PR 1616

3. Getting rid of registries

See github issue #1602.

Dave Cramer: https://w3c.github.io/epub-specs/epub33/rs/#sec-xhtml-custom-attributes

Dave Cramer: we said that vendors may define custom attributes, and then we setup a custom registry to track these
… HTML has quite a few ways for users to add attributes
… it seems to me a that it would be a great benefit to remove something that was never used, and which takes as further from HTML

Dan Lazin: why would this be bad for HTML?

Dave Cramer: name space attributes create issues for us in future because we can’t use them in HTML serialization

Dan Lazin: so proposal here is to remove entire section on custom attributes?

Dave Cramer: yes

Proposed resolution: Remove all references to custom attributes (Wendy Reid)

Dan Lazin: +1

Brady Duga: +1

Matthew Chan: +1

Dave Cramer: +idpf:1

Wendy Reid: +1

Marisa DeMeglio: +1

Shinya Takami (高見真也): +1

Toshiaki Koike: +1

Resolution #2: Remove all references to custom attributes

Dan Lazin: for clarity, when I reported that as bug, I thought that vendors WERE using this, but just not reporting into the registry

Dave Cramer: no, don’t think that is the case

4. Restrictions on container-constraints scripts

See github issue #1523.

Dave Cramer: this refers to scripts that run inside iframes
… we say that such scripts should not modify parent in DOM or other documents in publication, must not modify the size of its containing rectangle
… the idea is that container-constrained scripts should stay in their containers
… Ivan was wondering whether using attributes to do this would accomplish the same thing, and be checkable by epubcheck
… i looked into the sandbox attribute, but nothing seemed like a perfect match for what we want to achieve

Brady Duga: i don’t think sandbox is appropriate here, its for security and we’re concerned with layout
… the fact that the script cannot touch things outside of yourself, is by definition
… if you do touch outside things, no longer are you “container-constrained”
… so maybe rewrite this language as defining what it is
… “a container-constrained script is… doesn’t affect things outside itself, etc.”
… and anything not contained is considered spine level

Dave Cramer: but then who’s responsibility is it to enforce that? The RS?

Brady Duga: this is being done for publishers because we want to enable some scripting without breaking the content
… if they chose to ignore this and the content breaks, then they’ll just learn to stop

Dave Cramer: Ivan was also concerned about this from a testing perspective
… can’t reasonably write a validator to check every javascript for whether or not it goes outside its container
… but what we are leaning towards almost seems to move that section into the definitions
… maybe we can take this back to Ivan and Matt?

Brady Duga: you could almost just turn that paragraph into a bullet point

Dave Cramer: or just say “container-constrained script does NOT… etc.”

Wendy Reid: okay, so maybe no proposal for now, and we can just comment on the github ticket

Marisa DeMeglio: what do people use container-constrained scripts for?
… widgets?

Brady Duga: yeah, some little interactive thing. 3D model, for example

5. Quick reference pages

See github issue #1517.

Dave Cramer: this is a feature request
… someone wants to do pop-up reference pages, like a modal pop-up
… it would appear to the user without changing the user’s reading location
… i think there have been precedents
… sounds Microsoft Reader pagelits
… linear=”no”, that spawned a pop-up in front of the existing page
… this strikes me as potentially useful, but also a huge can of worms
… we’d have to describe complex visual rendering of something in epub
… how do we respond to requests like this?
… we could say “use HTML techniques”, but most of those may not work in epub

Wendy Reid: this came up in Locators call
… the question was raised about the positioning of index in RS
… most RS have separate TOC that can be accessed without changing reading position
… so what about index?
… we’ve never seen it done
… maybe cause there are clear indicators for what a TOC is
… nothing analogous for index
… i think we need to define how modals should appear, but maybe just elevate some common elements to same semantic level as TOC
… like for index, map, etc.
… then RS could choose to visually treat that the way they do TOCs

Brady Duga: this is probably out of scope for now?
… and it seems like maybe we could do this using existing markup
… maybe have note, “if you have target blank pointing to something within the epub then display like a modal”

Dan Lazin: if we were to grant this, people would use this to do all sorts of weird UI things
… might be good for making ebooks less tied down to replicating print books
… so this feature would be for whatever the authors wants to put in this separate window
… but I’d like clarification on how we normally deal with feature requests

Dave Cramer: the TOC is interesting because the spec mandates a navigation document
… we call it out in the manifest
… and we require that a RS make the text and links of navigation document available even if the linked document is not in the spine at all (linear=”no”)
… epub is sort of different from the web because the RS decides how UI works, and author just provides the content inside
… not sure what to think about attempts to change that fundamental division
… open to experimentation in this area
… i’d want to see interest from content creators and interest from RS developers
… they need to tell us how such an interface would work

Dan Lazin: something that seems analogous here is a widget framework like Chrome extension or Google Docs add-ons
… those are more apps than content
… but just like here, Google Docs creates the UI, but extensions have some control
… we could think of 3 categories, normal content, model content, and non-modal content outside of the main document (e.g. sidebar)

Dave Cramer: this sounds like a job for the CG
… they can better incubate, gather support
… and that’s more our process for feature requests
… also remember that Opera had something like this, like a “secondary browsing context”?
… you could make it open a side window

Brady Duga: agree that this should go to CG
… we might want to have a more formal way to hook up the content experiments with the RS experiments
… so that there is a place to test the experimental content and vice versa

Wendy Reid: raise it with Mateus and Zheng
… so we’ll just comment on the issue and let them know that we are referring this to the CG

Dave Cramer: and tag Mateus and Zheng

6. What do we mean by support for “presentation logic”?

See github issue #1516.

Dave Cramer: we say RS must “honor presentation logic expressed through package document”
… mgarrish thinks we should just delete it since we already require all the pieces of that in other places in the RS spec
… making this statement redundant

Brady Duga: agree

Marisa DeMeglio: yes, agree

Proposed resolution: Drop the statement in issue 1516 (Wendy Reid)

Dave Cramer: +1

Wendy Reid: +1

Matthew Chan: +1

Marisa DeMeglio: +1

Brady Duga: +1

Toshiaki Koike: +1

Masakazu Kitahara: +1

Dan Lazin: +1

Resolution #3: Drop the statement in issue 1516

7. Handling non-Arabic page numbers

See github issue #1505.

Dave Cramer: what are the rules for RS when faced with non-Arabic page numbers?

Brady Duga: are there any rules for handling Arabic page numbers?

Dave Cramer: right, we haven’t really said anything about this

Brady Duga: Arabic or otherwise

Dave Cramer: we’ve left a lot of these UI decisions up to RS
… some RS will use the content of the pagelist if it exists instead of internal page numbering
… assume these would just use whatever string is in there

Dan Lazin: that’s true for Apple

Brady Duga: true in Play Books

Dave Cramer: yep, backmatter in educational books often use letters

Brady Duga: we often see a mix of Arabic numerals and other stuff

Dave Cramer: not sure I see the problem here
… is there any guidance in the pagelist section on this?

Wendy Reid: don’t think so
… the context of this is really how RS communicate non-Arabic page numbers, but if RSes already have a solution…

Dan Lazin: there is an issue with the string-based solution with TTS and AT
… cannot pronounce arbitrary string
… maybe possible to solve it with ARIA label?

Dave Cramer: maybe have informative statement that if there is a pagelist, then RS should use strings embedded in pagelist?
… if they want to present that to user?

Wendy Reid: maybe refer this back to mgarrish? The a11y spec does not tell RS what to do, which is how it ended up here
… maybe we need him to explain why this came up in a11y in the first place

Dave Cramer: okay, so no resolution for now
… further discussion to come
… okay, thanks everyone!

Dave Cramer: rrsagent: bye

8. Resolutions