columns vs layout-ncol

[cscheid]

The following document works in HTML but not in PDF:

---
title: A title
format: html
---

:::: columns

::: column
First column
:::

::: column
Second column
:::

::::

The following document works in PDF but not in HTML:

---
title: A title
format: pdf
---

:::: {layout-ncol="2"}

::: column
First column
:::

::: column
Second column
:::

::::

This is very disorienting. We need to fix it.

[cscheid]

(Tareef reported this while working on a book.)

[mcanouil]

column* was designed by Pandoc for presentations format only.

layout-* and column* also do not produce the exact same thing.

[mcanouil]

• layout-ncol not working in beamer #5137

[mcanouil]

I've just tried the following and it works (break point at 768px width):

---
title: A title
format: html
---

:::: {layout-ncol="2"}

::: column
First column
:::

::: column
Second column
:::

::::

[cscheid]

gosh dang it, foiled by the HTML breakpoints again. Thanks!

I wish there was a way for us to see when columns are not rendered "optimally", like a debug mode for layout or something

[cscheid]

The wild thing is that columns works (yes, it's designed for other formats, but it works in HTML, and we don't warn users or anything). So the whole situation is extremely confusing and messy.

[cscheid]

In addition, the columns class also works in Epub, and I'm not sure if layout-ncols="2" will.

[cscheid]

Part of the issue is that the columns syntax is so obvious that people stumble into it - I suspect LLMs will make this issue worth. People test it in HTML, which works (and works independently of breakpoints!) Then, when they try it in docx or PDF, it doesn't work, and that's very surprising and annoying.

Simple syntax should always work in as many formats as we can get them to...

[mcanouil]

I totally agree, I personally "teach" about and use only layout-* but it's quite hard to find in the documentation.
I had too many issues when working multiple formats (HTML+Typst+Reveal.js) using conditional content without having to duplicate code.

Here is the documentation issue about "columns" being the only visible/searchable approach:

• Make using layout for arbitrary components more discoverable #6192

[cderv]

column* was designed by Pandoc for presentations format only.

This is documented for presentation only in Pandoc, it does get handles in all HTML format because they do style div.columns and div.column in the template
https://github.com/jgm/pandoc/blob/d3ed33bd005a7b54a11fbaf43b60ee5e28ab070d/data/templates/styles.html#L188-L189
including epub template
https://github.com/jgm/pandoc/blob/d3ed33bd005a7b54a11fbaf43b60ee5e28ab070d/data/epub.css#L152-L166

and on our side we tried to revert latest pandoc change on those columns by the way

quarto-cli/src/resources/formats/html/_quarto-rules.scss

Lines 649 to 662 in 56eb16a

	/* restore previous pandoc columns behavior
	(too many reports of slide layout breaking)
	see https://github.com/jgm/pandoc/pull/8237
	*/
	div.columns {
	display: initial;
	gap: initial;
	}
	div.column {
	display: inline-block;
	overflow-x: initial;
	vertical-align: top;
	width: 50%;
	}

All this is not conditional to slide format.

Simple syntax should always work in as many formats as we can get them to...

This would mean to me that we need to (re)approriate the columns syntax... This way in format like Docx we could use layout-ncol that we made work already.

Currently I would say mixing column div nested in layout-ncol div should be a warning (or even linting problem).
it is either columns format, or layout-ncol one.