Difficulty Accessing Logo Path in Typst Extension Due to Escaped Underscore and YAML Structure Concerns

[produnis]

Description

I’ve translated one of my LaTeX extensions to Typst, and while it mostly works, it took a lot of trial and error. My issue revolves around a logo file I export in the _extensions folder. When I try to access this file in my Typst template, the underscore in the path is escaped to \_.

I read that this problem can be solved with object.replace("\\", ""), which I tried implementing. However, I ended up needing two lines of code to handle the logo path correctly from the YAML header:

#let logo_path = "$logo$"
#let logo_path = logo_path.replace("\\", "")

This seems overly complicated, and I feel like there might be a more efficient way to handle this.

Additionally, my typst-show.typ file is almost empty because I’m fetching all YAML parameters directly in typst-template.typ. My understanding, though, is that all parameters/variables should ideally be defined or manipulated in typst-show.typ and then made available in typst-template.typ.

A minimal example can be found here: https://github.com/produnis/minimal_examples/tree/typstde

Any suggestions on simplifying the logo path handling or better structuring the YAML parameter usage would be greatly appreciated! :-)

[gordonwoodhull]

Yes, as I understand it the escaping is a limitation of Pandoc in that it processes metadata as markdown. I have places where I need to pass raw Typst code via metadata, and I ended up removing the backslashes and, even worse, running eval on the Typst side. 😱

But it works.

Best I can suggest is declaring a function to do the unescaping and then it can be done in one line in typst-show.typ. Like this, only hopefully you don't need the eval:

quarto-cli/src/resources/formats/typst/pandoc/quarto/typst-show.typ

Line 62 in adc7186

heading-color: unescape-eval("$brand.typography.headings.color$"),

[cscheid]

FWIW, there's a technique we use internally that is (partly) applicable here. A raw inline or block can be declared as pandoc-native, and Quarto will send the contents of that element through Pandoc's native reader. As a result

---
key1: '`Str "no--en--dashes--please"`{=pandoc-native}'
key2: yes--en--dashes--please
---

{{< meta key1 >}}

{{< meta key2 >}}

This doesn't help end users much, because the syntax is atrociously ugly to teach. But @gordonwoodhull you might be able to use this. @produnis I don't know how much syntax pain you're willing to tolerate...

What we should 100% have is a mechanism for some metadata to declare itself as "never-markdown", and then we convert those entries ahead of sending them to Pandoc.

[gordonwoodhull]

In my case I'm generating metadata in Lua, so I was able to mark the attribute value as raw Typst directly:

          color = pandoc.RawInline('typst', color)

Much nicer, no evil eval. See 5e37696

[produnis]

Today, archlinux updated to quarto 1.6.37,
and if you declared a cls in your YAML, quarto will insert a #set bibliography(style: csl) without giving you the chance to #let csl = csl.replace("\\", ""), leaving you with wrong "\" inside the path.

My workaround is to declare my own variable, like mycsl. This way, quarto won't trigger a #set bibliography() and I can replace the "\\" and call #set bibliography(style: mycsl) on my own.

[cscheid]

Could you give us a complete reprex? We'll open an issue.

[produnis]

Hi there, I uploaded my example to https://github.com/produnis/minimal_examples/tree/quartotypstcsl.

In _extensions/hsnr-article/_extension.yml I set the default csl to _extensions/hsnr-article/apa-single-spaced.csl.

In typst-template.typ, I tried to replace it in the first lines... I commented my #set bibliogrpahy call to show that quarto adds its own call...

[cscheid]

Thanks. Can you find an example that doesn't go through an extension?

[produnis]

sure, a "real" minimal example without any extension is here: https://github.com/produnis/minimal_examples/tree/quartotypstcsl2 (with a 2 at the end)

[cscheid]

Thank you! Tracking the regression here: #11552