Parameter in Quarto Typst not working with quarto::render function

[nithinmkp]

Description

I am basically trying to do some dynamic documents using quarto and typst. but I am not able to pass colours from R code to typst.

The issue is this:
I have penguins.qmd which is parameterised. The qmd file works as expected and creates a dynamic report which has also some nice colour codes based on the input parameter. But when I use render.R to create reports for all species, everything works except the colour coding. I can’t find a way to do this. Now since i need this report for three species of penguins in my analysis, i can change my params argument in penguins.qmd to generate report. This works as expected as shown below.

The report is also colour coded. Now i can use render.R to generate all reports at once. But the issue is although some contents change when we use this approach some contents do not change. as show below

as can be seen color is still of adelie in side bar. also in header it is still adelie. I guess it is beacause of my template issues. Hope i have made my issue clear!

Github Repo

[mcanouil]

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[mcanouil]

Parameters are for computations as already stated in your previous issue, they are not metadata, so you cannot do as --execute-param won't update the default metadata:

• https://github.com/nithinmkp/typst-paramter/blob/main/typst-show.typ#L9

So use actual metadata such as top level "species" and generate that metadata in your code.

```{r}
#| output: asis
#| echo: false
cat(sprintf("\n\n---\nspecies: %s\n---\n\n", params[["species"]]))
```

In the future, please share small example and don't use library(tidyverse) which means to install more than 100 packages for no reasons here.
The following is quite enough.

---
title: "Penguins"
format:
  typst:
    template-partials:
      - typst-show.typ
      - typst-template.typ
params:
  species: Adelie
engine: knitr
---

```{=typst}
#v(-1em)
*#text(size: 1.6em)[`{r} params[["species"]]`]*  
```

[nithinmkp]

Sure! noted!. But with this how will i control the position? and also about colour?

[mcanouil]

Please try the code shared in your example.

[nithinmkp]

Thanks a lot. Just one clarification. The ```{r}
#| output: asis
#| echo: false
cat(sprintf("\n\n---\nspecies: %s\n---\n\n", params[["species"]]))

[cderv]

For anyone searching for this:

Regarding using parameters for execution as Pandoc's metadata to be used in a document, a lua filter, or a template, you need to explicitly pass them. This is not done automatically. You can pass them all, or some of them.

See the latest article in Quarto R 📦 : quarto-dev.github.io/quarto-r/articles/dynamic-metadata.html#advanced-use-case-conditional-content-based-on-parameters

[nithinmkp]

I had solved this problem already. But little curious. How would you pass the meta variable from quarto to typst template?

[cderv]

Metadata can be used in Pandoc's template. So if you use as shown in the article, then you would have some metadata set for pandoc. and then they are available in template too.

[nithinmkp]

So if i understand correctly, only when we use write_yaml_meta_data function, we can access params using meta short code? what if we write params dynamically using cat function? will we be still able to access params using meta shortcode?

[cderv]

I am not sure to understand the cat() question.

Let me try to explain differently in a generic way.

• In quarto params field in YAML is not passed to Pandoc. It is only used to define some default parameters for knitr. Jupyter engine does not use this syntax. This is all explained at https://quarto.org/docs/computations/parameters.html

• params object is only accessible in computations. It won't be written anywhere to be passed to later processing by Pandoc in Quarto workflow. So if as any computation value, if it needs to be used later for a Lua filter or a Pandoc's template, it needs to be passed to Pandoc processing step.

• Metadata are a way to pass information to Lua filter in Pandoc, and they are also used as variables for pandoc's template. Defining metadata is done using YAML either in main header block, or later in the document. Using YAML block syntax

   
   ---
   key: value
   key2:
    - value1
    - value2
   key3:
     subkey: value3
   ---
   
  

• So for passing from R to Pandoc, one needs to write such block. Either using inline computation

   
   ---
   key: `{r} var_from_R`
   ---
   
  

  or using write_yaml_meta_data() help that will write this block for you.

I hope this clarify. Understanding the mechanism will let you adapt to what you want to do. And maybe the cat thing fits in there.

Hope it helps

[nithinmkp]

Perfect!! Thanks for the clarification

…

On Fri, 7 Nov 2025 at 3:25 PM, Christophe Dervieux ***@***.***> wrote: I am not sure to understand the cat() question. Let me try to explain differently in a generic way. - In quarto params field in YAML is not passed to Pandoc. It is only used to define some default parameters for knitr. Jupyter engine does not use this syntax. This is all explained at https://quarto.org/docs/computations/parameters.html - params object is only accessible in computations. It won't be written anywhere to be passed to later processing by Pandoc in Quarto workflow. So if as any computation value, if it needs to be used later for a Lua filter or a Pandoc's template, it needs to be passed to Pandoc processing step. - Metadata are a way to pass information to Lua filter in Pandoc, and they are also used as variables for pandoc's template. Defining metadata is done using YAML either in main header block, or later in the document. Using YAML block syntax --- key: value key2: - value1 - value2 key3: subkey: value3 --- - So for passing from R to Pandoc, one needs to write such block. Either using inline computation --- key: `{r} var_from_R` --- or using write_yaml_meta_data() help that will write this block for you. I hope this clarify. Understanding the mechanism will let you adapt to what you want to do. And maybe the cat thing fits in there. Hope it helps — Reply to this email directly, view it on GitHub <#13339 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/APQKHSZVIVYCLIFJLKM6CCD33RUBHAVCNFSM6AAAAACFZYD2ZGVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTIOJQGA4DGOA> . You are receiving this because you authored the thread.Message ID: ***@***.*** com>