JG: avoid blank lines in bulleted lists

[hturner]

Comment from @ajrgodfrey

Blank lines between items in bulleted lists cause screen readers to say "empty line" in between each item. It also produces messy HTML.

Example: RJ-2011-011

It also affects the visual formatting as a blank line is apparent between each list item - if The R Journal wants more space this should be controlled by the CSS rather than the R markdown/HTML.

[Abhi-1U]

I am a bit confused by this part, as the list's seem close without any spaces. My theory is that the screen reader might be skipping CSS marker(::marker) pseudo element found in the bullet lists.
Reference: https://developer.mozilla.org/en-US/docs/Web/CSS/::marker .

[hturner]

Hmm, @ajrgodfrey was able to create a reproducible example with and without the issue. Unfortunately I did not take a copy and cannot reproduce it now.

@ajrgodfrey do you still have this example, or can you recreate it?

[ajrgodfrey]

OK, cleaned up examples in attached file.

[hturner]

Looks like attachments don't come through to GitHub, maybe send to me by email?

[ajrgodfrey]

Done. I couldn't paste Rmd into the email as it gets mangled by Outlook. From: Heather Turner ***@***.***> Sent: Sunday, September 10, 2023 2:28 AM To: Abhi-1U/texor ***@***.***> Cc: Jonathan Godfrey ***@***.***>; Mention ***@***.***> Subject: Re: [Abhi-1U/texor] JG: avoid blank lines in bulleted lists (Issue #60) Looks like attachments don't come through to GitHub, maybe send to me by email? - Reply to this email directly, view it on GitHub<#60 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ADCZKGVXMO2BB5MVQLK6IXTXZR4HNANCNFSM6AAAAAA4QV3WHM>. You are receiving this because you were mentioned.Message ID: ***@***.******@***.***>>

[hturner]

Okay, this is a simplified version:

---
title: "bulleted list issues"
---

## Good bullets

- one
- two
- three

## Bad bullets

-   one blah

-   two what

-   three

However, we tested with html_document vs rjtools::rjournal_web_article. For the latter, both cases are "bad" and the bad bullets have a <p> tag nested within each <li> tag.

So this is mainly an rjtools issue I think, though assuming we can fix it there, it would be good if texor could ensure the Rmd source does not have blank lines between list elements.

[ajrgodfrey]

This comes through very badly in my email client. The input looks the same when I read it as an incoming message, but it looks as intended when it appears in the reply. <sigh> The first example should have one line break and no blank line whereas the second (bad) example has two line breaks and a blank line. The latter comes out very badly when rendered using rmarkdown::render(). The impact when listening to the screen reader is huge even though (as I understand it) there is only a small visual difference

[Abhi-1U]

I have tried to remove the extra paragraph element from the bullet list using a simple Lua filter.
Now this would not change the articles which have already been converted, I can really only do it with the remaining articles. Something similar can be done on R journal template level, but this might need some testing and verification.

Also this will only affect BulletLists and not other lists like OrderedLists or DescriptionList. So if similar issues exist for other list types, do let me know.

Meanwhile try out the latest patch of texor on the supplementary articles and check if the issues are resolved or not.

[hturner]

The patch seems to fix it for the bullet lists. The same problem exists for OrderedLists - in fact it seems to be worse as you always get <p> tags regardless of whether there are blank lines in the (R)markdown. I'm not sure how to test for DescriptionLists, but if they also end up with <p> in the HTML I would try to remove those.

[Abhi-1U]

list.zip
Try out this example with/ without the lua filter.
list.lua :

function BulletList(el)
    for i = 1,#el.content,1 do
        el.content[i][1] = el.content[i][1].content
    end
    return el
end

function OrderedList(el)
    for i = 1,#el.content,1 do
        el.content[i][1] = el.content[i][1].content
    end
    return el
end


function DefinitionList(el)
    print(el.content)
    for i = 1,#el.content,1 do
        new_dl ={}
        for k,v in pairs(el.content[i]) do
            if (v[1] ~= nil and k ~= 1 ) then
                print(el.content[i][k])
                el.content[i][k][1] = pandoc.Plain(el.content[i][k][1][1].content)
            end
        end

    end
    return el
end

list.rmd

---
title: "bulleted list issues"
output:
  html_document:
    pandoc_args:
      - --lua-filter=list.lua
---


#### Bullet List

-   A

-   B

#### Ordered List

1.  A

2.  B

#### Definition List

*rebib*
:   Convert and Aggregate Bibliographies


*texor*
:   Converting 'LaTeX' 'R Journal' Articles into 'RJ-web-articles'

[Abhi-1U]

Or try out the updated texor package with the supplement/metadata in the texor-rjarticle

[cderv]

Regarding the <p> elements you see in lists, they come from Pandoc itself

> pandoc -t html
## Good bullets

- one
- two
- three

## Bad bullets

-   one blah

-   two what

-   three

^Z
<h2 id="good-bullets">Good bullets</h2>
<ul>
<li>one</li>
<li>two</li>
<li>three</li>
</ul>
<h2 id="bad-bullets">Bad bullets</h2>
<ul>
<li><p>one blah</p></li>
<li><p>two what</p></li>
<li><p>three</p></li>
</ul>

You are comparing here the two possible syntax for Bullet List that Pandoc's Markdown offers: "compact" list vs “loose” list. See in their manual: https://pandoc.org/MANUAL.html#bullet-lists

If you want a “loose” list, in which each item is formatted as a paragraph, put spaces between the items

So I believe this is expected for the syntax with space between the items to have <p> in them.

• If this is an issue for accessibility, this should be reported in https://github.com/jgm/pandoc
• If you want to disallow loose list, you can probably use a Lua filter to make any loose list a compact list. It happens probably in the Pandoc Markdown reader directly, that will return Para and not Plain in AST. So you can't change the type, but you can make any Para a Plain.

   BulletList = function(b)
     -- Modify Bullet list content
     b.content = b.content:map(
       function(i)
       -- Change Para to Plain
         if #i and i[1].tag == "Para" then
           i[1] = pandoc.Plain (i[1].content)
           -- return modified element
           return i
         end
       end
     )
     -- return modified BulletList
     return b
   end

• This could be done while converting in texor or maybe in rjtools if you want to enforce that to the HTML format.

Hope it helps understand