Supply google slide notes to fig.alt

[cansavvy]

If no fig.alt is specified in the options, we want ottrpal to try to grab captions from the google slide notes and use that for the fig.alt option.

This will involve making some tweaks to the include_slide() function so that it checks for fig.alt spec and if none is given uses get_object_id_notes() function to get the notes and supply those as the fig.alt spec.

Happy to pair code on this where needed @howardbaek

[cansavvy]

For example:

We need google slide notes to be captions and vice versa for accessibility and for loqui video making.

So when people set fig.alt this is what happens when you hover your mouse over the image.

But we want this to automatically happen without us specifying a fig.alt option like this:

{r, echo = FALSE, fig.alt= "Major point!! example image"}
ottrpal::include_slide("https://docs.google.com/presentation/d/1YmwKdIy9BeQ3EShgZhvtb3MgR8P6iDX4DfFD65W_gdQ/edit#slide=id.gcc4fbee202_0_141")

Instead, we want to grab from Google slide notes to make the fig.alt so we don't have to specifiy UNLESS we want to OVERRIDE that caption from Google slides.

{r, echo = FALSE}
ottrpal::include_slide("https://docs.google.com/presentation/d/1YmwKdIy9BeQ3EShgZhvtb3MgR8P6iDX4DfFD65W_gdQ/edit#slide=id.gcc4fbee202_0_141")

The flow will look like this:

• Check if an image has a fig.alt spec. If not:
• Check if an image has Google slide notes (use the thing you worked on get_object_id_notes()). If not:
• Then put blank text.

This will involve edits to ottrpal::include_slide function and things it calls.

[howardbaek]

Regarding the flow, if the image does NOT have Google Slide notes, should we put something like "Alt text is empty"?

[howardbaek]

@cansavvy and I tried setting the current code chunk inside include_slide() with

include_slide <- function(url, output_dir = knitr::opts_chunk$get("fig.path"), overwrite = TRUE, ...) {

 # If fig.alt is not set
  if (is.null(knitr::opts_current$get("fig.alt")) {
    # Insert code to grab the individual google slide notes
    gs_notes <- "individual slide notes"
   
   # Unlock opts_current before calling $set()
    knitr::opts_current$lock(FALSE)

    # Try to set the fig.alt option
    knitr::opts_current$set(fig.alt = gs_notes)

    # Other ways we tried to set fig.alt:
    # options$fig.alt <- gs_notes
    # knitr::include_graphics(outfile, fig.alt = gs_notes)
  }
  outfile <- gs_png_download(url, output_dir, overwrite = overwrite)
  knitr::include_graphics(outfile, ...)
}

and failed.

To ask for help, I left a comment on a knitr issue: yihui/knitr#1798 (comment) and asked on Posit community: https://community.rstudio.com/t/setting-fig-alt-using-knitr-knit-hooks/174159

[sckott]

What about eval https://stackoverflow.com/a/47399915

[howardbaek]

@sckott Could you elaborate more? I can't figure out how this relates to the fig.alt chunk option