I’d heard rumour about the use of XHTML for fixed layouts in InDesign before the announcement of the new Creative Cloud 2014 suite this month, and having text-based pages — instead of them being purely image-based — sounded like a fantastic thing.
Add that Adobe included the ability to export the
epub:type attribute, and it seemed like there was a lot to look forward to as far as making accessible ebooks.
But the all important question lingered… what would the actual output look like, and would it match the hype?
Full disclosure, I’m not a power user of InDesign. I’m not even much of a user of InDesign, to be honest, as I don’t work on book layouts. I’ve certainly had enough exposure to what comes out of the program over the years, however, having converted publisher files to braille.
My point is only that I’m not going to engage in anything resembling a comprehensive review of the program. I downloaded the trial version out of curiosity to keep up with how the EPUBs are being generated, and what follows are observations focused solely on some key accessibility criteria.
My primary curiosity was to see what would happen to basic markup structures like headings, lists and tables in fixed layout rendering, so I added a few samples and… the output file only had paragraphs in it. Alas.
To make sure I hadn’t misformatted the document, I exported to a reflowable EPUB and sure enough there were all the proper list and table tags, including the start attribute on a continuation. So there is a bright side.
I honestly wasn’t terribly surprised to see lists and tables turned into paragraphs, either, as I had a feeling that an InDesign fixed layout would mimic the text areas of PDFs (we are talking about Adobe, after all). But not even retaining heading markup was a bit of a let down.
Looking closer at the lists, the first thing that caught my attention was that the list numbering was retained in the visual output, but there were no numbers in the markup (i.e., no indication to the user that they were in a list, or what kind of list).
My first thought was that a CSS style was injecting the numbers, but the paragraphs all had the same class values. Digging a little further into the CSS, I found a transparent background image with the numbers underlying the paragraphs (it also provides the table borders):
Lists are about as poorly formatted for accessible reading as you can get, in other words, short of using
br tags to separate entries.
Tables, as you might imagine, weren’t any better. Each cell is a paragraph, so any indication of what is a header and where rows begin or end is lost. The user gets a sea of paragraphs to navigate through.
I expected to find a way to designate the reading order of the objects on the page, but with fixed layouts you have to be aware that the order you add the objects is the order they will be generated in the output.
You’re probably familiar with the Articles pane, and being able to drag the objects into it to build a reading order for export, but this doesn’t appear to have any effect on the EPUB fixed layout export. I built a new order and exported to both reflowable and fixed layout, and only the reflowable version matched the article order.
In other words, be aware of the order in which you add new text objects to a page if you’re only generating a fixed layout ebook. If you’re inserting dialogue, for example, and add one character’s answer before the other asks the question, that’s how some people will read it.
The other feature being touted in this release is the ability to add the
epub:type attribute to the output. To do so, you have to select the object you want to tag, go to the export options and then you can select a semantic:
While this is generally a good thing to be able to do, the list of semantics isn’t completely valid; you may wind up with errors depending on which ones you use.
There were a number of draft educational terms added in 3.0.1 that were changed during the development of the EDUPUB profile. The original, now invalid, terms are available under the educational section:
qna has survived from the list. All of the others are now prefixed with “learning-” to avoid future conflicts.
heading-number semantic in the titles section is now
Although the epub:type field in the dialog allows you to input any value you want, the annoying thing is it will reject any value that isn’t in the dated list that was used to add the presets. In other words, you’ll have to wait for a future update before can use the correct terms. In the meantime, I’d suggest avoiding all of the above.
Additionally, a number of terms have deprecated and are no longer recommended for use:
annoref. I’m not sure yet how epubcheck will report these, but whatever future version incorporates the changes will likely only emit an informational note about their use. Still, best to avoid deprecated things.
You’ll also need to avoid the
figure semantic, as it’s not valid in XHTML content. Like the table and list semantics, it was added to enhance the navigability of media overlays (i.e., to allow escaping and skipping of structures). But unlike the table and list semantics, which have been rightly excluded from InDesign’s list,
figure was not. Go figure.
These semantic flaws are minor in the grand scheme of things, as I’m not sure what uptake adding them will gain. It’s more likely the education semantics won’t see wide usage until EDUPUB is more stable, at which point InDesign would need a patch to align with it.
So while pure fixed layouts don’t look too appealing for accessible reading, not all is doom and gloom with InDesign. The markup coming out of the reflowable export is very nice.
If I were a betting man, I’d interpret the way fixed layouts have been implemented as providing a meaningful route to accessible reflowable publications, while retaining the concept of a pixel precise page. While some features may net no benefit for fixed layouts, like setting the reading order, they will net you a good reflowable alternative, so it’s not like they’re useless and not worth doing.
As it is, though, the fixed layout output itself is a probably a step down from a tagged PDF, at least as far as structure retention goes. There’s hope the markup and accessibility will improve with time, as the reflowable output has, but for now a fixed layout EPUB coming out of InDesign isn’t reaching the pinnacles of accessible markup.
As I said out the outset, though, having the text available is still miles ahead of any program that generates bitmap images to make fixed layouts.
And once the Multiple Renditions Publications spec is finalized, who knows, maybe Adobe will add the option to export both versions and let the end user choose which they prefer.