Dynamically generating figures with captions in Word output from Rmarkdown document

Question

I'm trying to generate a Word document with figures. I use {officedown} and {officer} packages. I need to do it dynamically, in a loop since I don't know how many figures there will be. This is my Rmarkdown code:

---
output:
  officedown::rdocx_document:
    plots:
      caption:
        style: Table Caption
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE, message = FALSE, warning = FALSE)
```

```{r}
library(dplyr)
library(flextable)
library(officer)
```


```{r}
block_toc(seq_id = "fig")
```


```{r results='asis'}
ttp <- c(3, 7)
test_items <- c("item A", "item B", "item C")

fpars <- lapply(test_items, function(ti) {
  fpar(
    ftext("Application of "),
    ftext(ti),
    ftext(" Variable text - describe any test item-related effects"),
    ftext(" (see "),
    run_reference("fig:results1"),
    ftext(")."),
    fp_p = fp_par(padding.bottom = 12)
  )
})

do.call(block_list, fpars)
```


```{r}
titles <- lapply(seq_len(length(ttp)), function(i) {
  sprintf(
    "My custom figure caption with %s, having %s side effects",
    paste(test_items, collapse = ", "),
    ttp[i]
  )
})
```


```{r}
tmps <- lapply(seq_len(length(ttp)), function(i) {
  tmp <- tempfile(fileext = ".png")
  png(tmp, width = 6, height = 5, units = "in", res = 120)
  plot(iris[sample(1:150, 30), i + 1:2])
  dev.off()
  return(tmp)
})
```


```{r}
fpars <- lapply(seq_len(length(ttp)), function(i) {
  fpar(
    run_autonum(
      seq_id = "fig",
      pre_label = "Figure ",
      bkm = paste0("fig:results", i),
      bkm_all = TRUE,
      prop = fp_text(bold = TRUE, font.size = 12)
    ),
    titles[[i]],
    external_img(src = tmps[[i]], width = 6, height = 5)
  )
})

do.call(block_list, fpars)
```

The problem is when I generate the table of figures in the rendered document. It looks like this:

An entry is kept together with the image itself, I don't know why. I save temporary png files to be able to use them inside fpar function. Using plot function directly inside fpar causes bad effects. Maybe there's another/better way?

I found this construction useful, but unfortunately it puts captions under the figures by default. My goal is figure captions behave more like table captions, ie a caption is above a figure.

```{r fig.cap=unlist(titles)}
plot(iris[1:10, 1:2])
```

How can I generate the plots with captions dynamically with {officedown} or {officer} packages?

Answer 1

The only issue is about the last lapply, you need to put the image in a separate paragraph, so a for loop will be easier to stack 2 paragraphs into a list instead of 1 for each iteration.

---
output:
  officedown::rdocx_document:
    plots:
      caption:
        style: Table Caption
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE, message = FALSE, warning = FALSE)
```

```{r}
library(dplyr)
library(flextable)
library(officer)
library(officedown)
```

```{r}
block_toc(seq_id = "fig")
```

```{r}
ttp <- c(3, 7)
test_items <- c("item A", "item B", "item C")

fpars <- lapply(test_items, function(ti) {
  fpar(
    ftext("Application of "),
    ftext(ti),
    ftext(" Variable text - describe any test item-related effects"),
    ftext(" (see "),
    run_reference("fig:results1"),
    ftext(")."),
    fp_p = fp_par(padding.bottom = 12)
  )
})

do.call(block_list, fpars)
```


```{r}
titles <- lapply(seq_len(length(ttp)), function(i) {
  sprintf(
    "My custom figure caption with %s, having %s side effects",
    paste(test_items, collapse = ", "),
    ttp[i]
  )
})
```


```{r}
tmps <- lapply(seq_len(length(ttp)), function(i) {
  tmp <- tempfile(fileext = ".png")
  png(tmp, width = 6, height = 5, units = "in", res = 120)
  plot(iris[sample(1:150, 30), i + 1:2])
  dev.off()
  return(tmp)
})
```


```{r}
fpars <- list()
for (i in seq_along(ttp)) {
  fpars[[length(fpars)+1]] <- fpar(
    run_autonum(
      seq_id = "fig",
      pre_label = "Figure ",
      bkm = paste0("fig:results", i),
      bkm_all = TRUE,
      prop = fp_text(bold = TRUE, font.size = 12)
    ),
    titles[[i]]
  )
  fpars[[length(fpars)+1]] <- fpar(
    external_img(src = tmps[[i]], width = 6, height = 5)
  )
}

do.call(block_list, fpars)
```

This is an answer for "how to do it with officer" from scratch.

But the following is much more simple. There is an option fig.topcaption that do the same thing.

---
output:
  officedown::rdocx_document:
    plots:
      caption:
        style: Table Caption
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE, message = FALSE, warning = FALSE)
```

```{r}
library(dplyr)
library(flextable)
library(officer)
library(officedown)
```

```{r}
block_toc(seq_id = "fig")
```

```{r fig.cap = "miaou", fig.topcaption=TRUE}
plot(cars)
```

```{r fig.cap = "ouaf", fig.topcaption=TRUE}
plot(cars)
```