Is it possible to change the fig.cap chunk option within knitr? - r

Question

I'd like to change the fig.cap chunk option within a chunk for a knitr document. I tend to write a lot of reporting code that looks like the following to take a plot out of a tibble and use the associated caption with it.
```{r fig, fig.cap=d_plot$caption}
d_plot <- [load the plotting tibble from prior work]
knit_print(d_plot$figure[[1]])
```
Something similar to what I'd like to do is the following, but where the caption actually shows up. And, better yet would be if it would modify fig.cap and fig.scap with the possibility of having multiple knit_print() calls with multiple sets of figures.
---
title: "Untitled"
author: "William Denney"
date: '2022-04-19'
output: pdf_document
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo=FALSE, warning=FALSE, error=FALSE)
library(tidyverse)
library(knitr)
```
# Test
```{r functions, include=FALSE}
knit_print.fig_n_cap <- function(x) {
lapply(x$figure, knit_print)
opts_chunk$set(fig.cap=x$caption)
}
as_fig_n_cap <- function(x) {
stopifnot(is.data.frame(x))
stopifnot("figure" %in% names(x))
stopifnot("caption" %in% names(x))
class(x) <- c("fig_n_cap", class(x))
x
}
p <- ggplot(data.frame(x=1:3, y=1:3), aes(x=x, y=y)) + geom_line()
d <- as_fig_n_cap(tibble(figure=list(p), caption="My caption"))
```
```{r}
knit_print(d)
```