new crossrefs+flextable+docx interaction

[cscheid]

In .docx format, crossreferenceable code cells with flextable outputs cause Microsoft Word to emit a warning about a malformed document.

This doesn't happen when the code cell isn't crossreferenceable, so we're doing something bad to it.

[cscheid]

This is part of #4944.

[cscheid]

I spent a couple of hours trying to figure out what is going wrong and failed here - I can't tell what we might be emitting that's bad.

[cscheid]

Let's check non-table crossrefs (duh)

[cderv]

Just adding an example about this for context

---
title: demo
format: docx
---

```{r lib}
library(flextable)
```

```{r}
#| label: tbl-test
#| tbl-cap: "Caption"

flextable(head(mtcars)) 
```

[altonrus]

Thank you to the developers working on this! I discovered something interesting when using Quarto's new custom float cross-reference types to implement a workaround that may help you debug.

In the YAML header you can define a new custom table type. I used 'table' as the key instead of 'tbl'.

---
title: demo
format: docx
crossref: 
  custom:
    - kind: float
      key: table
      latex-env: table
      reference-prefix: Table
      space-before-numbering: true
      latex-list-of-description: Table
---

::: {#table-sample}

```{r}
flextable(head(mtcars)) 
```

Table caption here.

:::

As shown in @table-sample

This works without the "unreadable content" warning. BUT if I tell Quarto I want the caption on top of the table, as follows, I then get the unreadable content issue.

crossref: 
  custom:
    - kind: float
      key: table
      latex-env: table
      reference-prefix: Table
      space-before-numbering: true
      latex-list-of-description: Table
      caption-location: top

[cscheid]

@altonrus I edited your comment slightly. You can use more backticks in your code block declaration to allow backticks in the code.

[jhk0530]

@altonrus
It's amazing.
It solved my problem.
Thanks a lot.

[rps13]

Based on @altonrus finding the following works for me for docx output:

---
title: "Table test"
format:
  docx:
    tbl-cap-location: bottom
---

## Table test with reference

```{r, include=FALSE}
library("flextable")
```

```{r}
#| label: tbl-mt
#| tbl-cap: "mtcars with flextable"
head(mtcars) |> flextable()
```

See @tbl-mt.

The problem only seems to be the caption location for docx output.

[dchiu911]

I can confirm the warning only appears using default tbl-cap-location: top. Any updates to fix this?

[mcanouil]

Thank you for your interest.
Please refrain from asking updates, if there was one it would have been posted right here.
Instead, use the reactions on the original message to show you are interested in this issue to be fixed. This would help prioritise this over other issues. Again thanks for your interest.