Support for Dynamic Table Captions in Loops (R Markdown with LaTeX/PDF Output)

[vpoguru]

Description

Environment

• Quarto version: 1.7.34
• R version: 4.5.1
• OS: macOS Sequoia 15.7

Currently, Quarto does not support dynamic table captions generated inside loops in R chunks when rendering to PDF. This limits the ability to create programmatic or parameterized reports with tables generated in iterative structures.

Minimal Working Example

---
title: "Loop Demo"
format: pdf
---

```{r}
library(kableExtra)
```

```{r}
functionLoop <- function(id) {
  df <- data.frame(Type = "Loop", ID = id)
  kbl(df, caption = paste("Loop", id)) %>% print()
}
```

```{r}
#| label: loop
#| results: asis
for (i in 1:3) {
  functionLoop(i)
}
```

This results in the following warning:

Raw LaTeX table found with non-tbl label: tab:loop
Won't be able to cross-reference this table using Quarto's native crossref system.

Desired Behavior

1. Dynamic table captions inside a loop (especially when tables are printed using functions like kableExtra::kbl()).
2. Graceful handling of such captions in PDF output (LaTeX backend), including proper cross-referencing or a way to suppress the warning.

Use Case

This functionality would be helpful when programmatically generating multiple tables (e.g., by ID, group, or time point) in scientific and analytical reports, where captions must reflect the loop context.

Related

• kableExtra integration
• Cross-reference system and tbl-cap logic

[mcanouil]

Could you properly format your post using code blocks for code and terminal outputs? Thanks.
If your code contains code blocks, you need to enclose it using more backticks, i.e., usually four ````.
See https://quarto.org/bug-reports.html#formatting-make-githubs-markdown-work-for-us.

[mcanouil]

Where do you see it's not possible?
You need to write the right markup.

• https://mickael.canouil.fr/posts/2023-03-05-quarto-auto-table-crossref/

Note that your request is about computations which is not really the role of Quarto.
That's your job and the one of helper libraries to write the code to do this.

Changing this to Q&A as there are various discussions including on this GitHub repository on how to do this.
In the future, please search through discussions first:

• How to render multiple tables with subcaptions using kable() and a for loop? #5935
• How do I print data frames in for loop without using print function? #6033
• Using tabs in Quarto #9481
• Dynamic table names when using parameters in quarto #11249
• Implementing dynamic figure captions for multiple heatmaps within a loop in a Quarto document. #11853

[vpoguru]

Many thanks, @mcanouil, for your kind help — your suggestions and the links you provided were especially informative.

Your example works well in simple cases, including both your example and my minimal working example. However, in more complex documents — particularly when output is generated within functions — the use of child documents can interfere with the expected ordering of output. Unfortunately, even using kable_styling(latex_options = "hold_position") with kbl does not fully resolve the issue.

If I may ask, why you think this behavior falls outside the scope of Quarto? I’m asking because the warning appears before the first xelatex render step, which seems to suggest it might originate from Quarto itself. Additionally, the same code (with addition of the kbl option label) does not produce this warning when rendered with R Markdown, which further raises the question of whether Quarto’s processing might be involved.

[mcanouil]

Your example works well in simple cases, including both your example and my minimal working example. However, in more complex documents — particularly when output is generated within functions — the use of child documents can interfere with the expected ordering of output. Unfortunately, even using kable_styling(latex_options = "hold_position") with kbl does not fully resolve the issue.

This is R/knitr. Quarto does not change order of anything. It only takes the results of the engine. If something does not display the "right" way, then it's likely something in your code is wrong. When using knitr, to better understand the logic of literate programming, you can look at the resources such as:

• https://bookdown.org/yihui/rmarkdown-cookbook/
• https://bookdown.org/yihui/rmarkdown/

You need to understand what your code and the libraries you are using are producing (use keep-* options to keep the appropriate intermediate files).
Then look if that's what Quarto expects.

For instance, you should not emit tables with cross-reference which is what kableExtra does.
What you should do is to use Quarto's syntax described in the documentation:

• https://quarto.org/docs/authoring/cross-references-divs.html
• https://quarto.org/docs/authoring/tables.html#cross-references