EPUB 3 Working Group Telco — Minutes
Date: 2021-05-13
See also the Agenda and the IRC Log
Attendees
Present: Masakazu Kitahara, Matthew Chan, Dave Cramer, Wendy Reid, Shinya Takami (高見真也), Matt Garrish, Toshiaki Koike, Ben Schroeter, Brady Duga, Marisa DeMeglio, Fred Chasen, Dan Lazin
Regrets:
Guests:
Chair: Dave Cramer
Scribe(s): Matthew Chan
Content:
- 1. Update on TFs
- 2. Remove CSS Speech Support
- 3. Alt-text for cover images
- 4. Are fragment identifiers allowed in manifest?
- 5. Detailed definition of Content Display Area
- 6. SVG Validation
- 7. Handling of invalid properties
- 8. AOB?
- 9. Resolutions
Dave Cramer: welcome Fred!
Fred Chasen: i’m AC rep for Scribd (online subscription service for epubs, PDFs)
… good to be back
1. Update on TFs
Wendy Reid: this week both TFs met
… FXL TF solved issue with markdown not working in respec doc
… FXL TF will also start meeting biweekly instead of weekly
… Locators TF continue to go through use-cases
… considering potentially coming back around to page numbers
Dave Cramer: any questions above TFs?
2. Remove CSS Speech Support
See github issue #1298.
Dave Cramer: a while ago the CSS Speech module was unimplemented, but apparently it has come back, and is in CR now
… though still not aware of too many implementations, at least in epub world
… given CR status, not comfortable taking it out at this point
Brady Duga: there hasn’t been much harm to it being there yet, so it seems fine to leave it
Matt Garrish: as its unimplemented, nobody has done anything with it
… but if we’re not touching PLS or SSML then we can probably leave it too
Wendy Reid: do we know why CSS put this back on rec track?
… wonder if it is reviving due to resurgence of voice tech
Dave Cramer: did some quick searching this AM, and there seem to be a few voice over things that will read a few of these properties
Matt Garrish: it’s also been stripped down a little
Dave Cramer: okay, so we close the issue
Proposed resolution: Close issue 1298 (Wendy Reid)
Ben Schroeter: +1
Shinya Takami (高見真也): +1
Matthew Chan: +1
Toshiaki Koike: +1
Wendy Reid: +1
Dave Cramer: +1
Matt Garrish: +1
Masakazu Kitahara: +1
Brady Duga: +1
Fred Chasen: +1
Resolution #1: Close issue 1298
3. Alt-text for cover images
See github issue #1300.
Dave Cramer: this was discussed in a11y call this morning
Matt Garrish: we didn’t end with a proposal
… we’re looking for feedback from RS people about which of the possible solutions could realistically be implemented
Brady Duga: not sure how we get covers
Wendy Reid: probably sent separately
4. Are fragment identifiers allowed in manifest?
See github issue #1303.
Dave Cramer: i made an epub that had fragment identifier in href
… epubcheck threw an error
… but not sure which section of the spec this requirement came from
… so something to think about, especially as we’re rewriting the spec to refer to WHATWG URL spec
Ben Schroeter: would we need to do some epubcheck work if we were to decide to allow these fragment identifiers?
Dave Cramer: yes, but that shouldn’t be an obstacle, not big code change
Ben Schroeter: any downside? could it be abused?
Matt Garrish: just curious what the expectation is for RS if it is a fragment? What is RS supposed to do?
… load then scroll to fragment?
… and what about only having each resource listed once?
Dave Cramer: i think this is the same as activating a link in toc, i.e., yes to scroll
… but not suppress any of the document before the fragment
Brady Duga: how would that work in the spine? So chapter 1 is beginning of chapter, but chapter 2 is link to middle of the book?
Dave Cramer: yes, but we could have a note to say not to do that
Ben Schroeter: is there a legitimate reason to do this?
… or is this just to fix the epubcheck thing?
Matt Garrish: suspect this has something to do with the requirement to point to a resource, not a fragment of that resource
Brady Duga: maybe if you want to skip some kind of chapter heading for each chapter, so that you start with the first paragraph of the chapter?
Wendy Reid: we’ve had some cases where the entire book is in a single HTML file
… so this would allow you to actually navigate to the inside chapters?
Ben Schroeter: what about the fact that fragments need to be allowed for refines and stuff like that?
Matt Garrish: that’s not in the manifest
Dave Cramer: a valid reason for changing the spec is to make it match reality, and given that we already enforce this, allowing a fragment here would vastly complicate the responsibilities of an RS
… i think we just say hrefs in items shouldn’t have fragments
Matt Garrish: and the URL spec has a type that specifically can’t have fragments
… so easy to do in spec
Wendy Reid: is that the current test in the PR that you have out?
Matt Garrish: yeah (I didn’t know we had an issue out for this at the time)
Proposed resolution: Merge PR 1670, close issue 1303 (Wendy Reid)
Shinya Takami (高見真也): +1
Toshiaki Koike: +1
Masakazu Kitahara: +1
Proposed resolution: Merge PR 1670, close issue 1303, forbidding fragment identifiers in hrefs for items (Wendy Reid)
Dave Cramer: +1
Matt Garrish: +1
Ben Schroeter: +1
Brady Duga: +1
Matthew Chan: +1
Wendy Reid: +1
Fred Chasen: +1
Shinya Takami (高見真也): +1
Resolution #2: Merge PR 1670, close issue 1303, forbidding fragment identifiers in hrefs for items
5. Detailed definition of Content Display Area
See github issue #1306.
Dave Cramer: supposed to be the area in the display for epub content documents, excluding borders, margins, etc. injected by RS
… touches upon what part of screen real-estate should be controlled by author vs RS
… is just purely a FXL issue?
Fred Chasen: one place where this comes up is the little page dog-ear icon that clashes with book
Matt Garrish: we haven’t spec’ed what a viewport is, then we tried to describe a part within the viewport where content is displayed
… hard for us to be very specific about this
Dave Cramer: then is it possible to be more specific? Esp. given that RS might mess with putting more margin on body so that content doesn’t clash with bevel
… is there anything to be gained by being more precise?
Brady Duga: +1
Wendy Reid: are we talking about reflow, or FXL? Because the problems around headers, footers, etc. are mainly a problem for reflow where authors might have their own ideas about these regions
… for FXL the only question is whether it fits within the screen
Brady Duga: Content Display Area is only used within FXL (except for definitions)
… the idea was that RS should not mess with visuals in cases of FXL
… but Content Display Area technically applies to everything, because its just in the definitions
Dave Cramer: so is restricting the definition a solution?
Brady Duga: we could
… also, looking at the definitions, its not clear what the difference between viewport and Content Display Area is supposed to be
Ben Schroeter: I think there should be general guidance that RS should not obscure publisher content
… for the question at hand, I think the definition we have is suitable
… not sure how much more precise we can be
Dave Cramer: one more factor is that we’ve quite often had request for “full bleed” even in reflow
… e.g. where authors want something like an image to take up the entire screen
… e.g. in chapter opening photos in recipe books
Matt Garrish: should we try to move it over to RS spec, and try to explain the concept of Content Display Area?
… seems to apply only to RS rendering of FXL content
Shinya Takami (高見真也): +1 to mgarrish
Dave Cramer: this could really use a diagram to help explain
… i’ll look into that
Ben Schroeter: maybe we just need to reframe the question to how should RS accommodate the desire for full bleed content?
Brady Duga: there are plenty of FXL implementations that enable full bleed
Dave Cramer: and some user gestures make an overlay appear over the content
6. SVG Validation
See github issue #1323.
Dave Cramer: one of the complicating factors is undated references to specs, and now we have SVG1 and SVG2
Brady Duga: would prefer if we didn’t validate SVG
… this came up because there was an SVG 1.1 with a rel=no refer
, and this failed epubcheck
… i’ve found a couple other SVG validation errors that came up because of things that weren’t valid in 1.1
… and even if we do validate, we can only say that it was valid to an SVG Schema at the time of validation
Matt Garrish: compounding the problem is that validator.nu
has partially gone with SVG2, with no plans to fully move to SVG2
Brady Duga: i understand need for validity of XHTML, as XHTML is often edited by hand
… not true for SVG, which are often made by tools
… so you’re putting authors at the mercy of their tools, if those tools are generating invalid SVG
… and note that at this point spec doesn’t require validation
Dave Cramer: is there a requirement for well-formedness of XML?
Ben Schroeter: what about the XML entities in the DTDs of the SVG?
Dave Cramer: we’re not touching anything about rendering or processing, just saying that spec does not require validity, therefore epubcheck does not need to check validity
Brady Duga: if we don’t have requirement for validity, then Ivan’s issue goes away
Matt Garrish: i we’ve always had requirement that things conform to XHTML syntax
… but what about when SVGs are embedded in the content?
Dave Cramer: maybe our current action item is to talk to Romain about how this would affect epubcheck
… would also like to hear what Ivan says about this
7. Handling of invalid properties
See github issue #1673.
Matt Garrish: when I was making the URL spec change this came up
… when property values expand, they are supposed to expand into valid URL string
… assuming that if it is invalid, then RS should ignore property
Brady Duga: there are also situations where RS is suppose to ignore in failure case
Dave Cramer: right, this causes as little disruption to reading experience as possible
… e.g. not doing something to alert the reader
Proposed resolution: If a property is invalid, ignore it, close issue 1673 (Wendy Reid)
Ben Schroeter: +1
Shinya Takami (高見真也): +1
Brady Duga: +1
Matt Garrish: +1
Dave Cramer: +1
Matthew Chan: +1
Fred Chasen: +1
Toshiaki Koike: +1
Wendy Reid: +1
Resolution #3: If a property is invalid, ignore it, close issue 1673
8. AOB?
Wendy Reid: I sent invites for F2F earlier today
… will circulate agenda when we have one drafted
… let us know if you want to add anything specific to agenda
Dave Cramer: will try to tackle some of the bigger issues, e.g. HTML serialization
… okay, thanks everyone! Talk to you soon!
Dave Cramer: RRSAgent: bye
9. Resolutions
- Resolution #1: Close issue 1298
- Resolution #2: Merge PR 1670, close issue 1303, forbidding fragment identifiers in hrefs for items
- Resolution #3: If a property is invalid, ignore it, close issue 1673