Generating two distinct html outputs from the same document

[zackbatist]

Description

I wonder if it would be feasible to use the same text to generate distinct html outputs. As far as I understand it, only one set of formatting parameters can be applied for each format type (html, pdf, reveal, etc), but this seems like a very arbitrary limitation.

This could be useful for distributing and making decisions about different formatting options without having to revert all changes for each iteration. It could also be useful for preparing different versions of documents that include or exclude cut content using conditional content parameters ({.content-visible when-format="html-v1/2/x"}, for example).

I think this request aligns with the whole ethos of markdown-based writing, which holds that one text may be used to produce various styled outputs.

[mcanouil]

It's already possible to do things like that.

---
format:
  html-one:
    html-one: true
  html-two:
    html-two: true
---

{{< lipsum 1 >}}

:::: {.content-visible when-meta="html-one"}

This content is only visible in **html-one** format.

:::

:::: {.content-visible when-meta="html-two"}

This content is only visible in **html-two** format.

:::

You can also implement more complex logic using QUARTO_EXECUTE_INFO: https://quarto.org/docs/blog/posts/2025-10-13-1.8-release/#accessing-execution-information

[cderv]

HTML output are usually excluded from format links. When you want to serve several HTML file, using website project is usually more natural.

Though other-links can be leverage for custom navigation

---
title: testing format-links
format:
  html+one:
    html-one: true
    output-file: one.html
  html+two:
    html-two: true
    output-file: two.html
format-links: false
other-links: 
    - href: ./one.html
      text: Link to HTML One
      icon: filetype-html
    - href: ./two.html
      text: Link to HTML Two
      icon: filetype-html
---

{{< lipsum 1 >}}

:::: {.content-visible when-meta="html-one"}

This content is only visible in **html-one** format.

:::

:::: {.content-visible when-meta="html-two"}

This content is only visible in **html-two** format.

:::

[mcanouil]

And for what I recall from the internal, the modifier syntax is using + "officially" (meaning from comment in the codebase 😅 )

format:
html+one:
html-one: true
html+two:
html-two: true
Though we probably do not protect againt using - usually used for opting out a pandoc variants.

Why would block - while that's what is used for custom formats?😅
+ can be used to add Pandoc extensions.
I believe variant is to be used to control Pandoc extensions.

[zackbatist]

HTML output are usually excluded from format links.

Yes, this seems to be the case, unless I manually add them. Although I realize its not a priority, it might be nice to make this more programmatic.

[mcanouil]

HTML output are usually excluded from format links.

Yes, this seems to be the case, unless I manually add them. Although I realize its not a priority, it might be nice to make this more programmatic.

I would say it's unlikely to happen in a foreseeable future as this requires the various HTML files to have different names and I don't see how Quarto could possibly choose relevant file names for the user automatically.

Using both Reveal.js and HTML is already a source of issues regarding ressources, etc.

[cderv]

Why would block - while that's what is used for custom formats?

The custom formats is using - to separate the 'format name' to 'format target' e.g. acm-pdf
Which is different from pdf-acm. The latter would look for a custom format, while the former would consider acm to be modifier or a variant.

I am not saying it would block, but the design from code comment is to use + as modifier. But again this is old undocumented things that can benefit a new look as long it is not breaking.

quarto-cli/src/core/pandoc/pandoc-formats.ts

Lines 217 to 220 in 28d535a

	// Group the items into variants and modifiers
	// variants are valid markdown variants
	// modifiers are gmail style `+` syntax to allow the same base format
	// to be used with varying options (e.g. pdf+draft, pdf+final)

I believe variant is to be used to control Pandoc extensions.

Not sure about your comment, but in doubt, I am not talking about variant: YAML config. I mean that
acm-pdf+foo is valid for example, and acm-pdf+foo-smart would also be valid. smart would be matched to Pandoc's extension.
But you're right to see that + or - can be used for Pandoc's extentions. So a pandoc extensions name can't be used as modifier, not even with +